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Статті в журналах з теми "FEMA DOCUMENT"
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Lukkunaprasit, Panitan, Nuttawut Thanasisathit, and Harry Yeh. "Experimental Verification of FEMA P646 Tsunami Loading." Journal of Disaster Research 4, no. 6 (December 1, 2009): 410–18. http://dx.doi.org/10.20965/jdr.2009.p0410.
Повний текст джерелаАнотація:
The 2004 catastrophe of the Indian Ocean tsunami prompted scientists and engineers to develop better guidelines for economically designed essential buildings that are capable of withstanding tsunami forces. A recent design guidelines document – FEMA P646 [1] published by the US Federal Emergency Management Agency (FEMA) – proposes a practical method to estimate the tsunami design forces at a given locality with a known maximum tsunami runup height. This paper focuses on verifying the method stipulated in FEMA P646 through laboratory experiments, assuming the beach condition similar to Kamala beach in Phuket, Thailand, which suffered great losses by the 2004 Indian Ocean tsunami. Our experimental results confirm that the predicted forces provide a reasonable upper bound for the measured forces.
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Malley, James O., Charles J. Carter, and C. Mark Saunders. "Seismic Design Guidelines and Provisions for Steel-Framed Buildings: FEMA 267/267A and 1997 AISC Seismic Provisions." Earthquake Spectra 16, no. 1 (February 2000): 179–203. http://dx.doi.org/10.1193/1.1586090.
Повний текст джерелаАнотація:
One of the important surprises of the Northridge earthquake of January 17, 1994, was the widespread and unanticipated brittle fracture of welded steel beam-to-column connections. Although no casualties or collapses occurred during the Northridge earthquake as a result of these connection failures, and many WSMF buildings were not damaged at all, a wide spectrum of brittle connection damage did occur, ranging from minor cracking to completely severed columns. This paper summarizes two of the most important documents that have been developed in response to the damage suffered to steel moment frame buildings in the Northridge earthquake. The first, FEMA 267, Interim Guidelines: Evaluation, Repair, Modification and Design of Welded Steel Moment Frame Structures, was generated from studies undertaken as part of a project initiated by the U.S. Federal Emergency Management Agency (FEMA) to reduce the earthquake hazards posed by steel moment-resisting frame buildings. The second document addressed in this paper is the 1997 edition of the American Institute of Steel Construction (AISC) Seismic Provisions for Structural Steel Buildings (commonly referred to as the AISC Seismic Provisions) that incorporates the new information generated by the FEMA-sponsored project and other investigations on the seismic performance of steel structures, and has been adopted by reference into the 2000 International Building Code (IBC).
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Han, Sharon. "Weathering the Twitter Storm." Information Technology and Libraries 38, no. 2 (June 17, 2019): 37–48. http://dx.doi.org/10.6017/ital.v38i2.11018.
Повний текст джерелаАнотація:
After a disaster, news reports and online platforms often document the swift response of public libraries supporting their communities. Despite current scholarship focused on social media in disasters, early uses of social media as an extension of library services require further scrutiny. The Federal Emergency Management Agency (FEMA) recognized Hurricane Sandy as one of the earliest U.S. disasters in which first responders used social media. This study specifically examines early uses of Twitter by selected public libraries as an information tool during Sandy’s aftermath. Results can inform uses of social media in library response to future disasters.
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Ismail, Refaat Taleb, K. Rama Mohana Rao, and Srikanth Devi. "Estimation of Lateral Load Distribution Pattens in Nonlinear Static Procedures for RCC Framed Buildings." International Journal for Research in Applied Science and Engineering Technology 11, no. 1 (January 31, 2023): 356–63. http://dx.doi.org/10.22214/ijraset.2023.48575.
Повний текст джерелаАнотація:
Abstract: In the context of the seismic evaluation of building structures, nonlinear static analysis that makes use of pushover processes is becoming an increasingly common technique in engineering practice. In order to carry out a pushover study, the document FEMA-356 (2000) suggests using a variety of distributions of lateral forces. The use of these force distributions, on the other hand, does not adequately reflect the effects of modifying dynamic parameters across the inelastic response or the influence of higher modes. Four different lateral load patterns are investigated in this body of work by contrasting the pushover responses of RCC moment frame buildings with five and twelve stories.
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Sobelson, PhD, Robyn K., Corinne J. Wigington, MPH, and Victoria Harp, BA. "A whole community approach to emergency management: Strategies and best practices of seven community programs." Journal of Emergency Management 13, no. 4 (July 1, 2015): 349. http://dx.doi.org/10.5055/jem.2015.0247.
Повний текст джерелаАнотація:
Objective: In 2011, the Federal Emergency Management Agency (FEMA) published the Whole Community Approach to Emergency Management: Principles, Themes, and Pathways for Action, outlining the need for increased individual preparedness and more widespread community engagement to enhance the overall resiliency and security of communities. However, there is limited evidence of how to build a whole community approach to emergency management that provides real-world, practical examples and applications. This article reports on the strategies and best practices gleaned from seven community programs fostering a whole community approach to emergency management.Design: The project team engaged in informal conversations with community stakeholders to learn about their programs during routine monitoring activities, site visits, and during an in-person, facilitated workshop. A total of 88 community members associated with the programs examples contributed. Qualitative analysis was conducted.Results: The findings highlighted best practices gleaned from the seven programs that other communities can leverage to build and maintain their own whole community programs. The findings from the programs also support and validate the three principles and six strategic themes outlined by FEMA. Conclusions: The findings, like the whole community document, highlight the importance of understanding the community, building relationships, empowering action, and fostering social capital to build a whole community approach.
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Mayes, Ronald, Nicholas Wetzel, Ben Weaver, Ken Tam, Will Parker, Andrew Brown, and Dario Pietra. "Performance based design of buildings to assess damage and downtime and implement a rating system." Bulletin of the New Zealand Society for Earthquake Engineering 46, no. 1 (March 31, 2013): 40–55. http://dx.doi.org/10.5459/bnzsee.46.1.40-55.
Повний текст джерелаАнотація:
The Christchurch earthquakes have highlighted the mismatch in expectations between the engineering profession and society regarding the seismic performance of buildings. While most modern buildings performed as expected, many buildings have been, or are to be, demolished. The ownership, occupancy, and societal costs of only targeting life-safety as the accepted performance standard for building design are now apparent in New Zealand.
While the structural system has a significant effect on the seismic performance of the entire building, including the contents, it is only about 20% of the total building cost. Hence, structural engineers should view the seismic performance in a wider context, looking at all the systems of the building rather than just the damage to structural items and life-safety.
The next generation of performance-based seismic design procedures, outlined in the FEMA P-58 document, provide engineers with the tools to express the seismic performance of the entire building in terms of the future life loss, facility repair cost and repair time. This paper will outline the FEMA P-58 procedure and present the results of a comparative study of six different structural systems for a three storey commercial and laboratory building: moment frame; buckling restrained braced frame; viscously damped moment frame; Pres-Lam timber coupled-walls; cast-in-place reinforced concrete shear wall; and base isolated braced frame. Each system was analysed as a fully non-linear structure and the calculated drifts and floor accelerations were input into the FEMA P-58 PACT tool to evaluate the overall building performance. The PACT tool performs loss calculations for the expected casualties, repair cost, and repair time from which a QuakeStar or SEAONC rating for the building can be obtained.
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Celenza, James. "Protecting Disaster Site, Support, and Recovery Workers." NEW SOLUTIONS: A Journal of Environmental and Occupational Health Policy 18, no. 3 (September 30, 2008): 329–32. http://dx.doi.org/10.2190/ns.18.3.f.
Повний текст джерелаАнотація:
When a disaster strikes, FEMA activates the worker safety and health provisions (annex document) of the National Response Plan (NRP). The annex describes actions needed to ensure that threats to safety and health are recognized, evaluated, and controlled consistently so that responders are properly protected during incident management operations. The activation of the Worker Safety and Health Annex gives the Occupational Safety and Health Administration (OSHA) the responsibility to coordinate a comprehensive response involving federal, state, and local agencies and private-sector organizations to ensure the safety and health needs of responders are met. There is confusion, however, as to whether OSHA is acting as an advisory “coordinator” or as an enforcement agency. OSHA personnel at the WTC and the Gulf region reported they were not clear what role they must perform (and the language in the National Response Plan is not explicit). Thus, the need for a clear and comprehensive mandatory program.
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Robertson, Ian, Gary Chock, and Juan Morla. "Structural Analysis of Selected Failures Caused by the 27 February 2010 Chile Tsunami." Earthquake Spectra 28, no. 1_suppl1 (June 2012): 215–43. http://dx.doi.org/10.1193/1.4000035.
Повний текст джерелаАнотація:
Following the 2010 Chile earthquake and tsunami, the authors participated in the EERI reconnaissance team that traveled to Chile to document damage and structural performance. The authors focused on tsunami damage following the earthquake. A summary of tsunami damage to structures is given. Based on a series of well-defined structural element failures at sites where inundation depth was measured, the team was able to evaluate the hydrodynamic loading required to cause these failures and derive estimated lower bound flow velocity overland during the event. It was estimated that the velocity exceeded 3.2 m/s in Talcahuano harbor and 4.3 m/s in the coastal town of Dichato. When found in proximity to damaged buildings and other larger structures of interest, these simple structures can serve as “flow surrogate instruments” to estimate the local flow velocity. Failure analysis of these simple structures indicated that the hydrodynamic loading estimates provided by FEMA P646 may be unconservative.
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Zsarnóczay, Ádám, Tamás Balogh, and László Gergely Vigh. "On the European Norms of Design of Buckling Restrained Braced Frames." Open Civil Engineering Journal 11, no. 1 (June 30, 2017): 513–30. http://dx.doi.org/10.2174/1874149501711010513.
Повний текст джерелаАнотація:
The application of buckling restrained braced frames is hindered in Europe by the absence of a standardized design procedure in Eurocode 8, the European seismic design standard. The presented research aims to develop a robust design procedure for buckling restrained braced frames. A design procedure is proposed by the authors. Its performance has been evaluated for buckling restrained braced frames with two-bay X-brace type brace configurations using a state-of-the-art methodology based on the recommendations in the FEMA P695 document. A special numerical material model was developed within the scope of this research to represent the behavior of buckling restrained braces more appropriately in a numerical environment. A total of 24 archetype designs were prepared and their nonlinear dynamic response was calculated using real ground motion records in incremental dynamic analyses. Evaluation of archetype collapse probabilities confirms that the proposed design procedure can utilize the advantageous behavior of buckling restrained braces. Resulting reliability indices suggest a need for additional regulations in the Eurocodes that introduce reasonable structural reliability index limits for seismic design.
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Ergunes, Orhan Ilkay, and Tulay Aksu Ozkul. "Seismic Assessment of Tall Buildings Designed According to the Turkish Building Earthquake Code." Civil Engineering Journal 8, no. 3 (March 1, 2022): 567–79. http://dx.doi.org/10.28991/cej-2022-08-03-011.
Повний текст джерелаАнотація:
For the first time, the 2018 edition of the Turkish Building Earthquake Code has added a dedicated chapter for the design of high-rise buildings in earthquake-prone areas. Keeping in view the widely practised design option of rigid shear walls at the centre of a high-rise structure, the latest code has additionally defined limits for shear-wall axial forces in high-rise buildings. The new shear-wall axial force limits have not been independently investigated for optimal design and criticality. This calls for a detailed investigation of the newly defined axial force limits for the design of high-rise buildings in Turkey, where seismic activity has historically remained high. This study, therefore, investigates the effect of variation in limit values of shear wall axial forces on the collapse prevention of such buildings. A high-rise building designed entirely according to the code was chosen as the base model. The location of the building is in Istanbul, which has the highest number of tall buildings as compared to other cities in Turkey. A total of 7 alternative models were created by changing the concrete material class and the thickness of shear walls. This approach allowed us to quantify the effect of shear-wall thickness and its criticality against another important design consideration, i.e., the compressive strength of concrete. Forty different earthquake ground motion records were used to analyse the models to determine how critical the axial force ratio of the shear walls is in terms of collapse probability. The method proposed in the Federal Emergency Management Agency (FEMA) document FEMA P695 was followed to determine the collapse levels for the high-rise structures. A nonlinear analysis was performed to analyse the failure safety of the models. Results indicate that an increase or decrease in the axial force ratios by more than 15% renders the structure either overdesigned or deficient. Doi: 10.28991/CEJ-2022-08-03-011 Full Text: PDF
Дисертації з теми "FEMA DOCUMENT"
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Cosgrove, Samantha Jo. "Drop, Cover, and Hold On: Analyzing FEMA's Risk Communication through Visual Rhetoric." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6211.
Повний текст джерелаАнотація:
This project seeks to understand the relationship between visual rhetoric and power structure between FEMA’s Earthquake publications and their audience. Research shows images leave a longer impression on readers than text, causing more studies to focus on visuals rather than just text in technical communication. Author uses Critical Discourse Analysis to analyze the images in relation to text, design, and intended audience to determine what information is being privileged. It is determined that homeowners are being privileged with information over non-homeowners, established through a collection of images and image types. The lack of information for non-homeowners could result in injury or death of potential disaster victims, making it crucial for technical document revision.
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Borowiec, Anita. "New acrolein production route starting from alcohols mixtures over FeMo-based catalysts." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10153/document.
Повний текст джерелаАнотація:
L'acroléine est le plus simple des aldéhydes insaturés, qui - en raison de sa réactivité élevée - trouve des applications comme produit intermédiaire dans l'industrie chimique (par exemple pour la synthèse d'acide acrylique et la production de méthionine (i.e. acide aminé essentiel)). Récemment, on a observé une augmentation de la demande mondiale de produits dérivés de l'acroléine, qui devrait croître de façon continue au cours des prochaines années. De nos jours, l’acroléine est obtenue par oxydation du propylène, et donc ce procédé est basé sur des ressources fossiles qui ne cessent de décroitre. Ce travail propose une nouvelle méthode de production d'acroléine à partir de matières premières renouvelables – un mélange d’alcools formé de méthanol et d'éthanol. Cette réaction a été étudiée et optimisée en travaillant sur : les conditions de réaction via l’établissement d’un plan d’expériences afin de minimiser le nombre de tests catalytiques à réaliser, les modifications de la formulation catalytique FeMoOx (i.e. différents rapports Mo / Fe, température de calcination, et l’ajout d’éléments basiques (e.g. La, Ce) pendant la synthèse) et enfin l’utilisation d’un second catalyseur pour balancer les propriétés acides-bases nécessaires à l’obtention de notre molécule cibleAcrolein is the simplest unsaturated aldehyde, which - due to its high reactivity - finds applications as an intermediate in the chemical industry (e.g., for acrylic acid and methionine production). Recently, a worldwide demand increase of acrolein derivatives was observed, which is expected to continuously grow within the next years. However, nowadays acrolein is commercially obtained by propylene oxidation, where the raw material comes from fossil resources. This work proposes a new method of acrolein production starting from renewable feedstock – methanol and ethanol mixture. This reaction was approached by reaction conditions optimization (i.e. Design of Experiment method do decrease the number of catalytic tests and save time), FeMoOx modifications (e.g. various Mo/Fe ratios, calcination temperature, and basic elements addition) and a second catalyst utilization (e.g. single commercial oxides and silica-based materials) in order to balance the acid base properties
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Sarkar, Prasanta. "Simulation de l'érosion de cavitation par une approche CFD-FEM couplée." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI016/document.
Повний текст джерелаАнотація:
Ce travail de recherche est dédié à la compréhension des mécanismes physiques de l’érosion de cavitation dans un fluide compressible à l’échelle fondamentale de l’implosion d’une bulle de cavitation. Suite à l’implosion d’une bulle de vapeur à proximité d’une surface solide, des très hautes pressions sont générées. Ces pressions sont considérées responsables de l’endommagement (érosion) des surfaces solides observé dans la plupart des applications. Notre approche numérique démarre avec le développement d’un solveur compressible capable de résoudre les bulles de cavitation au sein du code volumes finis YALES2 en utilisant un simple modèle de mélange homogène des phases fluides. Le solveur est étendu à une approche ALE (Arbitraire Lagrangien Eulérien) dans le but de mener des simulations d’interaction fluide-structure sur un maillage mobile. La réponse du matériau solide est calculée avec le code de calcul éléments finis Cast3M, et nous a permis de mener des simulation avec un couplage d’abord monodirectionnel, ensuite bidirectionnel, entre le fluide et le solide. On compare des résultats obtenus à deux dimensions, puis à trois, avec des observations expérimentales. On discute les chargements de pression estimés, et les réponses de différents matériaux pour des implosions de bulle à des différentes distances de la surface. Enfin, à travers l’utilisation de simulations avec couplage bidirectionnel entre fluide et solide, on identifie l’amortissement des chargements de pression pour les différents matériauxThis research is devoted to understanding the physical mechanism of cavitation erosion in compressible liquid flows on the fundamental scale of cavitation bubble collapse. As a consequence of collapsing bubbles near solid wall, high pressure impact loads are generated. These pressure loads are believed to be responsible for the erosive damages on solid surface observed in most applications. Our numerical approach begins with the development of a compressible solver capable of resolving the cavitation bubbles in the finite-volume solver YALES2 employing a simplified homogenous mixture model. The solver is extended to Arbitrary Lagrangian-Eulerian formulation to perform fluid structure interaction simulation with moving mesh capabilities. The material response is resolved with the finite element solver Cast3M, which allowed us to perform one-way and two-way coupled simulations between the fluid and solid domains. In the end, we draw comparisons between 2D and 3D vapor bubble collapse dynamics and compare them with experimental observations. The estimated pressure loads on the solid wall and different responses of materials for attached and detached bubble collapses are discussed. Finally, the damping of pressure loads by different materials is identified with two-way coupled fluid-structure interaction
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Ifis, Abderrazzaq. "La nouvelle approche hybride MAX-FEM pour la modélisation thermomécanique des couches minces." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0044/document.
Повний текст джерелаАнотація:
De cette thèse, une nouvelle méthode éléments finis hybride MAX-FEM dédiée à la modélisation thermomécanique des structures avec couches minces a été développée. Cette nouvelle approche se base sur un couplage analytique-numérique de deux méthodes : les Développements Asymptotiques Raccordés (MAE) et la Partition de l'Unité (PUM). Ce couplage consiste à construire l'enrichissement de la PUM par MAE est mène à une forme corrigée de la méthode des éléments finis classique (FEM). Cette correction est obtenue à travers des matrices de correction contenant les informations géométriques et caractéristiques du matériau de la couche mince. Les matrices introduites par l'approche MAX-FEM simplifient son implémentation numérique sous différents codes de calculs (MATLAB, ABAQUS, ...) et permettent l'obtention de la solution globale en un seul calcul. Les résultats obtenus par la MAX-FEM pour des applications 1D et 2D thermomécaniques montrent une très bonne précision avec un temps de calcul minimal et sans raffinement de maillage. De plus, la MAX-FEM surmonte les limitations de la MAE ainsi que celle de la PUM en termes de nombre de calculs, de la sensibilité aux propriétés des matériaux, des conditions aux limites ainsi que l'intégration numérique. Finalement, l'approche MAX-FEM est exploitée pour le développement d'un nouveau protocole expérimental dédié à la caractérisation thermique des couches minces. Ce protocole vise l'identification, de manière simple, de la conductivité thermique de la couche mince après son élaboration et sous les deux régimes transitoire et permanent. L'approche consiste à confronter la nature du transfert thermique d'une éprouvette homogène à une contenant une couche mince. La différence relevée est directement liée à la conductivité thermique de la couche mince. Les résultats obtenus, après réalisation du banc d'essais, montrent une bonne précision de l'approche avec une méthodologie de mesure simple à mettre en oeuvreThis work introduces a new simplified finite elements method MAX-FEM based on hybrid analytical-numerical coupling. This method is intended to the multi-scales analysis of transient thermomechanical behavior of mediums containing thin layers such as bounded and coated structures. The MAX-FEM consists in correcting the classical Finite Elements Method (FEM) by correction matrices taking into account the presence of thin layers without any mesh refinement. The proposed correction is based on the analytical approach of Matched Asymptotic Expansions (MAE) and the numerical method of Partition of Unity Method (PUM). The developed approach can easily implemented under different numerical codes (MATLAB, ABAQUS, ...) and can be used to perform mechanical, thermal and thermomechanical analyses of 1D and 2D bounded and coated structures. The obtained results show a good accuracy with short computation time, and without any required mesh refinement. Also, the developed method overcomes the limitation of the MAE and PUM methods by exploiting the advantages of their coupling. Finally, the MAX-FEM approach was also used to develop an experimental test bench intended to the thermal characterization of thin layers. Indeed, a simple confrontation between the heat transfer in an homogeneous structure and a second structure with thin layer allows identifying the thermal conductivity in both transient and stationary regimes. The test bench is simple to release and the obtained results for brazed structure show a good accuracy of the developed approach
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Bourrel, Tristan. "Influence des longueurs internes sur la tenue mécanique d'un film anti-rayure." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE002/document.
Повний текст джерелаАнотація:
Notre connaissance des effets d'une rayure sur les surfaces polymères reste à approfondir. L'expérimentation donne des observations précieuses des phénomènes qui apparaissent durant la rayure, cependant, l'accès aux champs de contraintes et de déformations dans le matériau n'est pas possible, ce qui est pourtant un élément clé pour la prédiction de l'amorce des fissures.Nous utilisons un essai de rayure sur des matériaux transparents, qui permet la visualisation in situ des endommagements, des dimensions de la zone de contact et du frottement. Les endommagements, en termes de craquelures, fissurations et bandes de cisaillement sont identifiés sur trois polymères massifs (PMMA, CR39 & PC). En parallèle, nous utilisons la modélisation 3D par éléments finis pour étudier la réponse mécanique pendant la rayure de ces trois matériaux polymères, afin d’identifier des critères d'amorçage de fissures. Enfin, des systèmes revêtus sont étudiés et le délaminage et la fissuration du film sont discutés. Ces considérations font entrevoir les perspectives possibles en termes de pistes d'amélioration pour la protection des substrats par dépôt de films mincesOur knowledge of scratch effects on polymeric surfaces is still limited. The experimental approach gives precious observations of phenomena which occur during scratching, however, it does not allow to get insight the stress distribution within the material, a key feature for crack initiation prediction.A scratch test is used on transparent materials, that allows to visualize in situ damages appearance, the dimension of the contact zone and friction. The damages, in terms of crazing, cracking and shear bands are identified on three bulk polymers (PMMA, CR39 & PC).In parallel, we use 3D finite element modelling to study the mechanical response during a scratch test on these three polymeric materials, in order to identify crack initiation criteria.Finally, coated systems are studied and delamination/cracking of thin films are discussed. These considerations point to possible prospects in terms of improvement paths for the protection of substrates by thin films coating
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Wenzel, Christian. "Local FEM Analysis of Composite Beams and Plates : free-Edge effect and Incompatible Kinematics Coupling." Thesis, Paris 10, 2014. http://www.theses.fr/2014PA100107/document.
Повний текст джерелаАнотація:
Cette thèse traite des problèmes des concentrations de contraintes locales, en particularité des effets des bords libres dans des structures stratifiés. À l'interface entre deux couches avec des propriétés élastiques différentes, les contraintes ont un comportement singulier dans le voisinage du bord libre en supposant un comportement de matériau élastique linéaire. Par conséquent, ils sont essentiels pour promouvoir le délaminage. Via Formulation unifiée de la Carrera (CUF) différents modèles cinématiques sont testés dans le but de capter les concentrations de contraintes. Dans la première partie de ce travail, les approches de modélisation dimensionnelle réduits sont comparées. Deux classe principale sont présentés: la couche équivalent (ESL) et l'approche par couche, LW. Par la suite leurs capacités à capter les singularités sont comparées. En utilisant une fonction a priori singulière, via une expression exponentielle, une mesure des contraintes singulières est introduite. Seulement deux paramètres décrivent pleinement les composantes des contraintes singulières au voisinage du bord libre. Sur la base des paramètres obtenus les modèles sont comparés et aussi les effets sous des charges d'extension et de flexion et pour différents stratifiés. Les résultats montrent une nécessité des modèles complexes dans le voisinage du bord libre. Cependant loin des bords libres, dans le centre de plaques composite, aucune différence significative ne peut être noté pour les modèles plutôt simples. La deuxième partie de ce travail est donc dédiée au couplage de modèles cinématique incompatibles. Modèles complexes et coûteux sont utilisés seulement dans des domaines locaux d'intérêt, tandis que les modèles économiques simples seront modéliser le domaine global. La eXtended Variational Formulation (XVF) est utilisé pour coupler les modèles de dimensionnalité homogènes mais de cinématique hétérogènes. Ici pas de recouvrement de domaine est présent. En outre, le XVF offre la possibilité d'adapter les conditions imposées à l'interface en utilisant un paramètre scalaire unique. On montre que, pour le problème de dimensionnalité homogène, que deux conditions différentes peuvent être imposées par ce paramètre. Un correspondant à des conditions fortes des Multi Point Constraints (MPC) et un second fournir des conditions faibles. La dernière offre la possibilité de réduire extrêmement le domaine qui utilise le modèle cinématique complexe, sans perte de précision locale. Comme il s'agit de la première application de la XVF vers les structures composites, le besoin d'un nouvel opérateur de couplage a été identifié. Un nouveau formulaire est proposé, testé et sa robustesse sera évaluéeThis work considers local stress concentrations, especially the free-Edge effects of multilayered structures. At the interface of two adjacent layers with different elastic properties, the stresses can become singular in the intermediate vicinity of the free edge. This is valid while assuming a linear elastic material behaviour. As a consequence this zones are an essential delamination trigger. Via the Carrera Unified Formulation (CUF), different kinematical models are testes in order to obtain the correct local stress concentration. In the first part of this work, the reduced dimensional modelling approaches are compared. Two main class are presented: Equivalent Single Layer (ESL) models treating the layered structure like one homogenous plate of equal mechanical proper- ties, and the Layer Wise approach, treating each layer independently. Subsequently their capabilities to capture the appearing singularities are compared. In order to have a comparable measurement of those singularities, the obtained stress distributions will be expressed via a power law function, which has a priori a singular behaviour. Only two parameters fully describe therefore the singular stress components in the vicinity of the free edge. With the help of these two parameters not only the different models capabilities will be compared, but also the free edge effect itself will be measured and compared for different symmetrical laminates and the case of extensional and uniform bending load. The results for all laminates under both load cases confirm the before stated need for rather complex models in the vicinity of the free edge. However far from the free edges, in the composite plates centre, no significant difference can be noted for rather simple models. The second part of this work is therefore dedicated to the coupling of kinematically incompatible models. The use of costly expensive complex models is restricted to local domains of interest, while economic simple models will model the global do- main. The Extended Variational Formulation (XVF) is identified as the most suitable way to couple the kinematically heterogenous but dimensional homogenous models. As it uses a configuration with one common interface without domain overlap, the additional efforts for establishing the coupling are limited. Further the XVF offers the possibility to adapt the conditions imposed at the interface using a single scalar parameter. It will be shown that for the homogenous dimensional problem under consideration only two different conditions can be imposed by this parameter. One matching the strong conditions imposed by the classical Multi Point Constrains (MPC) and a second one providing a weak condition. The last one is shown to provide the possibility to reduce further the domain using the complex kinematical model, without the loss of local precision. As this is the first application of the XVF towards composite structures, the need for a new coupling operator was identified. A new form is proposed, tested and its robustness will be evaluated
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Chen, Shuai. "Investigation of FEM numerical simulation for the process of metal additive manufacturing in macro scale." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI048/document.
Повний текст джерелаАнотація:
La fabrication additive (FA) est devenue une nouvelle alternative pour la fabrication des pièces dans l'industrie. Cependant, il existe encore des limites pour ce procédé, en particulier la forme finale défavorable et les propriétés macroscopiques indésirables des pièces métalliques construites dans les systèmes de FA. La distorsion ou la fissure due à la contrainte résiduelle de ces pièces pose généralement de graves problèmes pour certains types de technologie de la FA métallique. Dans un système de FA, la qualité finale d'une pièce métallique dépend de nombreux paramètres de procédé, qui sont normalement optimisés par une série d'expériences sur des machines de FA. La simulation macroscopique dédiée au procédé de FA est une alternative potentielle pour les pièces métalliques fabriquées par la fabrication additive. Dans cette thèse, nous étudions d'abord le pré-processing de la simulation de FA par la méthode des éléments finis (FEM). Le procédé de fabrication additive est un phénomène multi-physique des champs couplés (champs thermique, mécanique et métallurgique). La simulation macroscopique est réalisée à deux niveaux différents. Au niveau de la couche, la reconstruction du modèle 3D est effectuée à partir du fichier de chemin de balayage de la machine de FA, basée sur la manipulation inverse de l'algorithme d'offsetting-clipping. Au niveau de la pièce, le modèle 3D de CAO est reconstruit dans un maillage des voxels, ce qui est pratique pour une pièce avec une géométrie complexe. Avec les températures de préchauffage différentes et les paramètres du procédé différents, la contrainte résiduelle d'une pièce est analysée. Ces simulations impliquent la technique potentielle pour réduire la contrainte résiduelle par l'optimisation des paramètres du procédé, au lieu de moyens traditionnels par augmenter la température de préchauffage. Basées sur la plateforme de simulation de FEM ci-dessus, deux simulations au niveau de ligne sont également étudiées dans cette thèse, visant à la relation entre le procédé de FA et la qualité finale de la pièce. Ces exemples démontrent la possibilité d'utiliser des simulations macroscopiques pour améliorer le contrôle de la qualité pendant le procédé de FA. Dans la première tâche, l'ensemble de données des paramètres de chauffage et la contrainte résiduelle sont générés par la simulation de FA. La corrélation entre eux est étudiée en utilisant des algorithmes de régression, tel que le réseau neuronal artificiel. Dans la deuxième tâche, un contrôleur de PID pour la boucle de rétroaction puissance-température est intégré dans la simulation de procédé de FA et l'auto-réglage de PID est numériquement étudié au lieu d'utiliser la machine de FA. Les deux tâches montrent le rôle important de la simulation de procédé macroscopique de FA, qui peut remplacer ou combiner les nombreuses expériences essai-erreur dans la fabrication additive métalliqueAdditive manufacturing (AM) has become a new option for the fabrication of metallic parts in industry. However, there are still some limitations for this application, especially the unfavourable final shape and undesired macroscopic properties of metallic parts built in AM systems. The distortion or crack due to the residual stress of these parts leads usually to severe problems for some kinds of metal AM technology. In an AM system, the final quality of a metallic part depends on many process parameters, which are normally optimized by a series of experiments on AM machines. In order to reduce the considerable time consumption and financial expense of AM experiments, the numerical simulation dedicated to AM process is a prospective alternative for metallic part fabricated by additive manufacturing. Because of the multi-scale character in AM process and the complex geometrical structures of parts, most of the academic researches in AM simulation concentrated on the microscopic melting pool. Consequently, the macroscopic simulation for the AM process of a metallic part becomes a current focus in this domain. In this thesis, we first study the pre-processing of AM simulation on Finite Element Method (FEM). The process of additive manufacturing is a multi-physics problem of coupled fields (thermal, mechanical, and metallurgical fields). The macroscopic simulation is conducted in two different levels with some special pre-processing work. For the layer level, the reconstruction of 3D model is conducted from the scan path file of AM machine, based on the inverse manipulation of offsetting-clipping algorithm. For the part level, the 3D model from CAD is reconstructed into a voxel-based mesh, which is convenient for a part with complex geometry. The residual stress of a part is analysed under different preheat temperatures and different process parameters. These simulations imply the potential technique of reducing residual stress by the optimisation of process parameters, instead of the traditional way by increasing preheat temperature. Based on the FEM simulation platform above, two simulations at line level are also studied in this thesis, aiming at the relation between the AM process and part's final quality. These examples demonstrate the feasibility of using macroscopic simulations to improve the quality control during the AM process. In the first task, dataset of heating parameters and residual stress are generated by AM simulation. The correlation between them is studied by using some regression algorithm, such as artificial neural network. In the second task, a PID controller for power-temperature feedback loop is integrated into AM process simulation and the PID auto-tuning is numerically investigated instead of using AM machine. Both of the two tasks show the important role of AM macroscopic process simulation, which may replace or combine with the numerous trial and error of experiments in metal additive manufacturing
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Hammood, Mohammed Naji. "A Meso-Macro Numerical Approach for Chloride Diffusivity Modeling Taking into Account Chloride Binding and Crack Evolution in Concrete." Thesis, Nantes, 2017. http://www.theses.fr/2017NANT4066/document.
Повний текст джерелаАнотація:
La pénétration des ions chlorure est la principale cause de la dégradation des structures en béton, par corrosion des armatures, entraînant un impact sévère sur leur durabilité et leur durée de vie. La pénétration de ces agents agressifs pourrait être favorisée davantage par la présence de fissures. Dans cet thèse, nous avons utilisé la méthode des éléments finis (EF) pour résoudre l'équation de la loi de Fick couplée à la capacité de fixation d’ions chlorure afin de modéliser la diffusion des ions chlorure à l’échelle mésoscopique. Dans un premier temps, nous avons considéré une représentation 3D d’un matériau, sain, hétérogène biphasé (comme le béton) ou les inclusions (granulats) sont noyées dans une matrice de mortier. Le problème des interfaces (inclusion/matrice) a été résolu en utilisant la méthode E-FEM (Embedded Finit Element Method). Au niveau de ces interfaces, nous avons introduit une discontinuité faible du champ de concentration de chlorures. Une approche d’homogénéisation par moyennes spatiales se basant sur les travaux de Pouya est également utilisée pour prédire les tenseurs de diffusivité macroscopiques des matériaux biphasiques. La comparaison avec l'équation de Maxwell et des résultats expérimentaux a été réalisée pour montrer la précision de l’approche numérique proposée. Dans un second temps, l’approche méso-macro est représentée pour introduire un modèle numérique capable de fournir des informations macroscopiques (tenseur de diffusion moyen) intégrant le niveau d’ouverture de fissure, le chemin de fissuration et l’hétérogénéité des matériaux quasi fragiles tels que les matériaux cimentaires (béton, mortier, ….). Dans ce cas, des points clés du processus de fissuration comme l’évolution d’une fissuration répartie vers une fissuration localisée (macro-fissure(s)), la tortuosité de la fissure et son anisotropie sont intégrées naturellement dans la diffusivité macroscopique. En fin, le tenseur défini est ensuite utilisé afin d'estimer la durée de vie des structures en béton, y compris l'effet de l'endommagement et de la mésostructure interneThe penetration of chloride ions has an essential responsibility in the degradation of concrete structures caused by reinforcement corrosion leading to a severe impact on the durability and service life of concrete structures. The problem becomes more critical with the existence of cracking which accelerate the penetration of chloride ions into concrete cover. In this work, the FE formulation for the numerical modelling of chloride ions diffusion accounting for chloride binding capacity in mesoscale concrete is introduced. The mesostructure is based on a twophase 3D representation of heterogeneous materials, such as concrete, where stiff aggregates are embedded into a mortar matrix. For this purpose, we turn to the Embedded Finite Element Method (E-FEM). This is performed by introducing a weak discontinuity in the chloride concentration field for finite elements where the physical interface is present. Numerical spatial homogenization experiments based on Pouya’s works are also performed on 3D mesostructures to compute macroscopic diffusivity tensors accounting for two-phase material. Comparison with Maxwell's equation and experimental results are carried out to show the accuracy of the proposed numerical approach. Finally, the meso-macro approach is presented to introduce a numerical model capable of providing macroscopic information (mean diffusivity tensor) integrating the level of crack opening, crack path and heterogeneity of materials in quasi-brittle concrete. The mesoscale coupling with the mass transport part is based on Fick’s Law with a modified diffusion coefficient taking into account crack opening and aggregates. The macroscopic diffusivity tensor integrates more complex features such as the cracking evolution process, tortuosity of the crack’s path, inducedanisotropy and presence of aggregates. The defined tensor is used afterwards in order to estimate the service-life of concrete structures, including the effect of the cracking and the internal mesostructure
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Cheng, Xianchao. "Contraintes thermiques dans les dépôts de couches minces pour les optiques rayons-X sous forte charge thermique." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY028/document.
Повний текст джерелаАнотація:
Les optiques multicouches pour rayons-X sont généralement constituées de centaines de périodes de couches alternées. L'épaisseur d'une période est de quelques nanomètres. Une multicouche est souvent déposée sur un substrat de silicium avec une taille typique de 60 × 60 × (60~300) mm3. Le rapport de dimensions (~107) entre la taille de l'optique et de l'épaisseur de l'empilement est très élevé et il peut conduire à un très grand nombre d'éléments (~1016). Certains éléments spéciaux avec fonctions de couche sont disponibles dans ANSYS (de 2011), ce qui signifie que les propriétés de chaque couche peuvent être définies. Par l'utilisation des éléments nommés « layer-functioned », le modèle d'analyse thermique-structurelle a été mise en œuvre pour les optiques multicouches. Le nombre d'éléments est réduit par un facteur supérieur à 30 et le nombre effectif de sous-couches gérables par les ordinateurs actuels augmente beaucoup. Basé sur la modèle d'éléments finis de l'optique multicouche, la distribution tridimensionnelle non-uniforme de température peut être simulée avec des paramètres variables de charge thermique, de conditions de refroidissement, de propriétés des matériaux, de géométries du substrat et des films de revêtement. Les contraintes et déformations thermiques peuvent être résolues quantitativement.Des miroirs à réflexion totale et des monochromateurs multicouches refroidis à l'eau et à l'azote liquide ont été étudiés avec des paramètres typiques de charge thermique, de refroidissement et de géométrie. Les effets de refroidissement de l'optique et de la charge thermique du faisceau de rayons-X ont été décrits. Il est montré que les influences de la température sur le revêtement et la déformation sont négligeables. La contrainte dans le substrat n'est que légèrement augmentée (<0.1%). Cependant, des fortes contraintes sont induites dans les couches en raison de la différence de CTE, ce qui peut être critique pour la survie de l'optique. Pour la condition de refroidissement à l'eau, la couche est sous contrainte de compression de plusieurs dizaines de MPa, ce qui est normalement inférieur à la résistance du matériau de la couche. Pour la condition de refroidissement à l'azote liquide, cependant, une grosse contrainte de traction de plusieurs centaines de MPa apparait dans la couche lorsque l'optique est refroidie jusqu'à la température de l'azote liquide (80 K). Cette contrainte de traction peut dépasser la résistance à la traction (UTS) pour certains types de matériaux de couche. La contrainte thermique dans l'optique multicouche dépend de la différence de CTE entre le matériau de la couche et le matériau du substrat, mais elle est indépendante de la différence des CTE entre les différentes sous-couches. En principe, pour minimiser la contrainte thermique, le matériau de revêtement doit avoir un CTE proche de celle du substrat, un module de Young et un coefficient de Poisson plus petits. En outre, une grande résistance du matériau de la couche est bénéfique pour sa capacité à résister à la contrainte thermique.Pour obtenir des informations appropriées sur le comportement des multicouches sous l'influence de la charge thermique, des propriétés telles que le module de Young, le ratio entre CTE et module de Poisson des multicouches sont déterminés indirectement en mesurant la variation de la courbure due au changement de température. Des couches simples de B4C, Pd et Cr et des multicouches [Pd/B4C] d'épaisseurs de l'ordre du nanomètre sont préparées et mesurées. Les résultats expérimentaux montrent que tous les matériaux étudiés présentent un CTE et/ou un module de Young inférieur par rapport aux données dans la littérature. Cela est particulièrement vrai pour les couches minces de B4C. Par conséquent, la contrainte thermique réelle et la contrainte dans les couches de revêtement d'un miroir ou de multicouches optiques sont sensiblement plus petites que les résultats calculés avec les propriétés des matériaux massifsMultilayer optics for X-rays typically consists of hundreds of periods of alternating sub-layers coated on a silicon substrate. The thickness of one period of sub-layers is a few nanometers. The silicon substrate is typically a block of 60 mm large, 60 mm wide and 60 to 300 mm long. The high aspect ratio (~107) between the size of the optics and the thickness of the multilayer can lead to a very large number of elements (~1016) for the numerical simulation (by FEA). Some special layer-functioned elements have been developed recently (in 2011) in ANSYS, which means the properties of each layer can be explicitly defined. In this work, the thermal-structural analysis model has been implemented for multilayer optics by use of these layer-functioned elements. The number of meshed elements is considerably reduced by a factor of more than 30 and the number of sub-layers feasible for the present computers is increased significantly. Based on the finite element model of multilayer optics, the non-uniform three-dimensional temperature distribution can be simulated with variable heat load parameters, cooling conditions, material properties and geometries of the substrate and the coating films. The thermal stress and deformation can be solved quantitatively.Single layer coated mirrors and multilayer monochromators cooled by water or liquid-nitrogen are studied with typical parameters of heat-load, cooling, and geometry. The effects of cooling-down of the optics and the X-ray beam heat-load are described. It is shown that the influences from the coating on temperature and deformation are negligible. The stress in the substrate is only slightly increased (<0.1%). However, large layer stresses are induced due to the different thermal expansion coefficients (CTE) between the layer and substrate materials, which are the critical issues for the survival of the optics. For the water cooling condition, the layer is under compressive stress of tens of MPa which is normally less than the strength of the layer material. For the liquid-nitrogen cooling condition, however, large tensile stress of several hundreds of MPa is formed in the layer as the optics is cooled more than 200 K down to the liquid-nitrogen temperature (80K). This tensile stress can exceed the ultimate tensile strength (UTS) for some kinds of layer materials. The thermal stress in multilayer optics depends on the difference in CTE between the layer material and the substrate material, but it is independent on the CTE difference between different sub-layers. In principle, to minimize the thermal stress, the coating material should have a CTE closer to that of the substrate, smaller Young's modulus and Poisson's ratio. Moreover, a higher strength of the layer material is beneficial for its ability to withstand the thermal stress.To acquire appropriate information about the behaviour of thin multilayer films under the influence of thermal loading, material properties such as Young's modulus, Poisson's ratio and CTE, of thin multilayer films are determined indirectly by measuring the curvature change due to uniform temperature change. B4C, Pd and Cr single layers and [Pd/B4C] multilayers of thicknesses in the nanometer range are prepared and measured. The experimental results show that all of the studied materials exhibit lower CTE and/or Young's modulus than expected from bulk data in the literature. This is particularly true for the thin B4C films. Therefore, the real thermal stress and strain in the coating layers of a mirror or multilayer optics are significantly smaller than the calculated results with bulk material properties.results with bulk material properties
10
Amdouni, Saber. "Numerical analysis of some saddle point formulation with X-FEM type approximation on cracked or fictitious domains." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0007/document.
Повний текст джерелаАнотація:
Ce mémoire de thèse à été réalisée dans le cadre d'une collaboration scientifique avec "La Manufacture Française des Pneumatiques Michelin". Il porte sur l'analyse mathématique et numérique de la convergence et de la stabilité de formulations mixtes ou hybrides de problèmes d'optimisation sous contrainte avec la méthode des multiplicateurs de Lagrange et dans le cadre de la méthode éléments finis étendus (XFEM). Tout d'abord, nous essayons de démontrer la stabilité de la discrétisation X-FEM pour le problème d'élasticité linéaire incompressible en statique. Le deuxième axe, qui représente le contenu principal de la thèse est dédié à l'étude de certaines méthodes de multiplicateur de Lagrange stabilisées. La particularité de ces méthodes est que la stabilité du multiplicateur est assurée par l'ajout de termes supplémentaires dans la formulation faible. Dans ce contexte, nous commençons par l'étude de la méthode de stabilisation de Barbosa-Hughes appliquée au problème de contact unilatéral sans frottement avec XFEM cut-off. Ensuite, nous construisons une nouvelle méthode basée sur des techniques de projections locales pour stabiliser un problème de Dirichlet dans le cadre de X-FEM et une approche de type domaine fictif. Nous faisons aussi une étude comparative entre la stabilisation avec la technique de projection locale et la stabilisation de Barbosa-Hughes. Enfin, nous appliquons cette nouvelle méthode de stabilisation aux problèmes de contact unilatéral en élastostatique avec frottement de Tresca dans le cadre de X-FEMThis Ph.D. thesis was done in collaboration with "La Manufacture Française des Pneumatiques Michelin". It concerns the mathematical and numerical analysis of convergence and stability of mixed or hybrid formulation of constrained optimization problem with Lagrange multiplier method in the framework of the eXtended Finite Element Method (XFEM). First we try to prove the stability of the X-FEM discretization for incompressible elastostatic problem by ensured a LBB condition. The second axis, which present the main content of the thesis, is dedicated to the use of some stabilized Lagrange multiplier methods. The particularity of these stabilized methods is that the stability of the multiplier is provided by adding supplementary terms in the weak formulation. In this context, we study the Barbosa-Hughes stabilization technique applied to the frictionless unilateral contact problem with XFEM-cut-off. Then we present a new consistent method based on local projections for the stabilization of a Dirichlet condition in the framework of extended finite element method with a fictitious domain approach. Moreover we make comparative study between the local projection stabilization and the Barbosa-Hughes stabilization. Finally we use the local projection stabilization to approximate the two-dimensional linear elastostatics unilateral contact problem with Tresca frictional in the framework of the eXtended Finite Element Method X-FEM
Книги з теми "FEMA DOCUMENT"
1
Lew, H. S. Supporting document for rehabilitation cost estimates of FEMA buildings. Gaithersburg, MD: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 1999.
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2
Lew, H. S. Supporting document for rehabilitation cost estimates of FEMA buildings. Gaithersburg, MD: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 1999.
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3
Lew, H. S. Supporting document for rehabilitation cost estimates of FEMA buildings. Gaithersburg, MD: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 1999.
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4
Çelebi, Mehmet. Seismic instrumentation of federal buildings: A strawman draft document for consideration by federal agencies, presented at the NEP meeting, July 8, 1997, FEMA building, Washington, D.C. [Menlo Park, CA]: U.S. Geological Survey, 1997.
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5
Çelebi, Mehmet. Seismic instrumentation of federal buildings: A strawman draft document for consideration by federal agencies, presented at the NEP meeting, July 8, 1997, FEMA building, Washington, D.C. [Menlo Park, CA]: U.S. Geological Survey, 1997.
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6
1977-, Perrin Clotilde, ed. Il fera beau, Julot! [France]: Rue du monde, 2004.
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7
Guzun, Vadim. Foametea, piatiletka și ferma colectivă: Documente diplomatice românești, 1926-1936. Baia Mare]: Editura Universității de Nord, 2011.
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8
Gines, Paul K. Comparison of FEM storage/retrieval machine documents to the ASME B30.13 specification. New York, NY: ASME Standards Technology, LLC, 2009.
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1798-1870, Baillargeon Charles-François, and Église catholique. Archidiocèse de Québec. Administrateur (1855-1867 : Baillargeon), eds. Circulaire: Permettez-moi d'appeler l'attention de Votre Grandeur sur le document ci-joint, qui lui fera connaître toute l'étendue de la calamité dont la ville de Québec vient d'être affligée .. [S.l: s.n., 1986.
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10
Aguilar Silva, Claudia. Técnicas de la Investigación. Universidad Nacional Autónoma de México, Facultad de Estudios Superiores Aragón, 2022. http://dx.doi.org/10.22201/fesa.9786073064576e.2022.
Повний текст джерелаАнотація:
Este texto ayuda a abordar herramientas que los estudiantes emplearán dentro y fuera de la licenciatura, como redactar adecuadamente, revisar fuentes, citar y realizar críticas a documentos, utilizar de manera correcta el método científico, así como construir instrumentos de recolección de datos son habilidades que puedes emplear no solo en la escuela, también en cualquier ámbito de la vida
Частини книг з теми "FEMA DOCUMENT"
1
Alsahly, Abdullah, Hoang-Giang Bui, Lukas Heußner, Annika Jodehl, Rodolfo Javier Williams Moises, Markus Obel, Marcel Stepien, et al. "Digital Design in Mechanized Tunneling." In Interaction Modeling in Mechanized Tunneling, 329–404. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-24066-9_6.
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AbstractDigital design methods are constantly improving the planning procedure in tunnel construction. This development includes the implementation of rule-based systems, concepts for cross-document and -model data integration, and new evaluation concepts that exploit the possibilities of digital design. For planning in tunnel construction and alignment selection, integrated planning environments are created, which help in decision-making through interactive use. By integrating room-ware products, such as touch tables and virtual reality devices, collaborative approaches are also considered, in which decision-makers can be directly involved in the planning process. In current tunneling practice and during planning stage, Finite Element (FE) simulations form an integral element in the planning and the design phase of mechanized tunneling projects. The generation of adequate computational models is often time consuming and requires data from many different sources. Incorporating Building Information Modeling (BIM) concepts offers opportunities to simplify this process by using geometrical BIM sub-models as a basis for structural analyses. In the following chapter, some modern possibilities of digital planning and evaluation of alignments in tunnel construction are explained in more detail. Furthermore, the conception and implementation of an interactive BIM and GIS integrated planning system, ‘‘BIM-to-FEM’’ technology which automatically extracts relevant information needed for FE simulations from BIM sub-models, the establishment of surrogate models for real-time predictions, as well as the evaluation and comparison of planning variants are presented.
2
Wilhite, Donald A., and Mark D. Svoboda. "Monitoring Drought in the United States: Status and Trends." In Monitoring and Predicting Agricultural Drought. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780195162349.003.0017.
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Drought occurs somewhere in the United States almost every year and results in serious economic, social, and environmental costs and losses. Drought is more commonly associated with the western United States because much of this region is typically arid to semiarid. For example, this region experienced widespread drought conditions from the late 1980s through the early 1990s. The widespread and severe drought that affected large portions of the nation in 1988 resulted in an estimated $39 billion in impacts in sectors ranging from agriculture and forestry to transportation, energy production, water supply, tourism, recreation, and the environment (Riebsame et al., 1991). In the case of agriculture, production losses of more than $15 billion occurred and especially devastated corn and spring wheat belts in addition to reducing exports to other nations. In 1995, the U.S. Federal Emergency Management Agency (FEMA) estimated annual losses attributable to drought at $6–8 billion (FEMA, 1995). Since 1995, drought has occurred in nearly all parts of the country, and many regions have been affected on several occasions and in consecutive years. Most of the eastern United States experienced an extremely severe drought in 1998– 99, and in parts of the southeast, drought occurred each year from 1999 through 2002, especially in Florida and Georgia. Figure 9.1 depicts nonirrigated corn yields for Nebraska for the period from 1950 to 2002. Nebraska is one of the principal agricultural states in the United States, and corn is one of its primary crops. The drought effects on yields are most apparent during the severe droughts of the mid-1950s, mid-1970s, 1980, 1983, 1988–89, and 2000. Extremely wet years, such as 1993 in the eastern part of the state, also depressed corn yields. Monitoring drought presents some unique challenges because of its distinctive characteristics (Wilhite, 2000). The purpose of this chapter is to document the current status of drought monitoring and assessment in the United States, particularly with regard to the agricultural sector.
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Basavaraju, Chakrapani, and Jason Lambin. "Subsection NB—Class 1 Components." In Companion Guide to the ASME Boiler & Pressure Vessel Codes, Volume 1, Sixth Edition, 6–1. ASME Press, 2023. http://dx.doi.org/10.1115/1.886519_ch6.
Повний текст джерелаАнотація:
Abstract This chapter discusses the structural limits in Section III NB and Section VIII Division 2 as related to specific structural failure modes considered applicable to pressure vessel and piping design. The rules and requirements for Section III NB and Section VIII Division 2 are based on the design-by-analysis philosophy addressing specific structural failure modes of structural collapse, rupture, instability, fatigue, and progressive deformation. The chapter begins with a discussion on the interactions between materials, environments, mechanical, and thermal loads as aided by other disciplines since this is critical for every part of every pressure vessel design. It provides a brief history of development of Code analytic tools and discusses the use of elastic 3D finite element analysis (FEA) results and the application of elastic-plastic (EP)-FEA. The chapter then discusses the intent of the primary stress limits in the Code. Consideration is given to the definitions in the Code and the discussion in the Criteria document. The chapter then addresses why the primary-plus-secondary stress intensity range is necessary and shows how to apply it. Two procedures for calculating stress intensity are presented, and the impact of thermal stresses is discussed for definition and application. The chapter also discusses six areas in which the Code presents fundamental procedures and expands on these fundamentals by presenting guidelines for a singular view of acceptable procedures that are consistent with the original intent for Section III and consistent with the current rules. Finally, it comments on the elastic-plastic FEA methods to protect against plastic collapse, to determine protection against local failure, and to assess fatigue and ratchet limits. History Tom Ahl was the original author of this chapter for the first edition. Marcus N. Bressler updated this chapter for the second and third editions. Chakrapani Basavaraju updated this chapter for the fourth, fifth and sixth editions. The current online edition has been updated by Chakrapani Basavaraju and Jason Lambin.
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Alarcon, Vladimir J., Joseph D. Nigro, William H. McAnally, Charles G. O’Hara, Edwin T. Engman, and David Toll. "Assessment of NASA’s Physiographic and Meteorological Datasets as Input to HSPF and SWAT Hydrological Models." In Geographic Information Analysis for Sustainable Development and Economic Planning, 1–19. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-1924-1.ch001.
Повний текст джерелаАнотація:
This chapter documents the use of simulated Moderate Resolution Imaging Spectroradiometer land use/land cover (MODIS 12 Q1), NASA-LIS generated precipitation and evapo-transpiration (ET), and Shuttle Radar Topography Mission (SRTM) datasets (in conjunction with standard land use, topographical and meteorological datasets) as input to hydrological models routinely used by the watershed hydrology modeling community. The study is focused in coastal watersheds in the Mississippi Gulf Coast, although one of the test cases focuses in an inland watershed located in northeastern Mississippi, USA. The decision support tools (DSTs) into which the NASA datasets were assimilated were the Soil Water & Assessment Tool (SWAT) and the Hydrological Simulation Program Fortran (HSPF). These DSTs are endorsed by several US government agencies (EPA, FEMA, USGS) for water resources management strategies. These models use physiographic and meteorological data extensively. Precipitation gages and USGS gage stations in the region were used to calibrate several HSPF and SWAT model applications. Land use and topographical datasets were swapped to assess model output sensitivities. NASA-LIS meteorological data were introduced in the calibrated model applications for simulation of watershed hydrology for a time period in which no weather data were available (1997-2006). The performance of the NASA datasets in the context of hydrological modeling was assessed through comparison of measured and model-simulated hydrographs. Overall, NASA datasets were as useful as standard land use, topographical, and meteorological datasets. Moreover, NASA datasets were used for performing analyses that the standard datasets could not made possible, e.g., introduction of land use dynamics into hydrological simulations.
Тези доповідей конференцій з теми "FEMA DOCUMENT"
1
Parker, Stephen M., Matthew C. Walter, and Daniel V. Sommerville. "Effects of Multiple Co-Linear Flaws on Crack Opening Area." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63689.
Повний текст джерелаАнотація:
Cracking in boiling water reactor (BWR) core shroud welds has been identified in operating nuclear plants worldwide. The nuclear industry has taken extensive efforts to disposition and evaluate core shroud cracking, most notably within the BWR Vessel and Internals Project (BWRVIP) where many industry guidance documents have been published regarding core shroud integrity [1, 2, 3, 4]. This guidance is predominately focused on evaluating crack stability. Calculating through-wall leakage was not previously a focus of the existing BWRVIP inspection and evaluation (I&E) guidelines for the core shroud; however, there is some guidance in the current documentation. In recent years there has been some evidence of through-wall indications in the core shroud where the through-wall indications were aligned in an array of co-linear, short, flaws. There is currently no BWRVIP document or other open literature, to the authors’ knowledge, that provides insight into whether the crack opening displacements (CODs) for an array of co-linear, through-wall cracks are larger than that calculated for a single through-wall crack. Developing an understanding of the effect of co-linear cracks on the CODs and subsequent crack opening areas (COAs) of each crack is important in augmenting the existing guidance on how to appropriately disposition through-wall cracking in reactor internal components. Specifically, it is important to know if multiple co-linear cracks can lead to individual COAs that are larger than for a single crack of the same length, in order to perform accurate leakage rate calculations. The purpose of the study documented in this paper is to characterize the COA for axial co-linear crack distributions compared to the COA of an individual crack. Cracks that are aligned in series with an uncracked ligament between them are considered to be co-linear. To better understand how these crack distributions behave, an evaluation is conducted to analyze axial co-linear flaw configurations in core shrouds using traditional linear-elastic fracture mechanics (LEFM) and finite element analysis (FEA) techniques. Through FEA, the COAs and displacements of various co-linear flaw configurations are calculated and compared to the COAs for single flaw configurations. These flaw geometries are useful for the purpose of determining the potential core leakage associated with through-wall co-linear cracks. Co-linear crack configurations for a range of crack sizes and geometries are parametrically evaluated based on the ligament length between the co-linear cracks. Results show that crack openings of co-linear flaw configurations compared to a single flaw can vary substantially depending the crack size and ligament length. Trends of these crack openings are summarized within this report. While the object of this work is to provide criteria for the evaluation of reactor internals, the results can be applied to evaluate COD and COA in any component for which the cracking configuration and inherent assumptions of LEFM are applicable.
2
Liu, Lin, and David Binney. "Nonlinear Finite Element Analysis of a Sharp Radius on the Shank of a Ring Locked Stud." In Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17618.
Повний текст джерелаАнотація:
This paper documents an investigation of the effect of a sharp radius on the shank of a ring locked stud. An industry specification for studs does not define a minimum size for the radius and very sharp radii have been found during inspection of some studs. Finite element analysis (FEA) is used to evaluate the stud as part of an assembled joint subject to fatigue loading. A parametric study is conducted, and high-fidelity modeling is adopted to correlate the FEA results with stud testing results. After a validated FEA model is confirmed, the elastic-plastic stress strain curve is applied in the FEA model. Three sizes of the radius are introduced in the model to evaluate the radius size effect on the vibratory stress under operational loads. The evaluation demonstrates that the radius size has a significant impact on its vibratory stress which in turn affects the calculated fatigue life.
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Udoyen, Nsikan, and David W. Rosen. "Description Logic Representation of Finite Element Analysis Models for Automated Retrieval." In ASME 2006 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/detc2006-99451.
Повний текст джерелаАнотація:
Adaptive reuse of archived parametric finite element analysis (FEA) models to model similar, new problems is an important part of the process of learning to apply the finite element method to specific domains. Retrieval of relevant archived models and supporting documents from electronic repositories is difficult when a modeler is unable to describe information needs precisely in a query using keywords. The use of description logic concepts to describe archived models and build expandable classification hierarchies to facilitate retrieval is proposed and illustrated. A domain-independent retrieval algorithm based on the traversal of description logic concept hierarchies is introduced. Its usefulness is asserted by: • showing that intent behind FEA models can be represented precisely using a fairly inexpressive description logic; • showing that standard description logic inference supports retrieval of FEA models based on a modelers’ intent.
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Smith, Steven M., and David N. Hutula. "Twice-Yield Method Abaqus Implementation With Application to a Thermally Shocked Stepped Pipe." In ASME 2021 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/pvp2021-61367.
Повний текст джерелаАнотація:
Abstract The Twice-Yield method is an elastic-plastic finite element analysis (FEA) pioneered by Professor Arturs Kalnins at Lehigh University which approximates the stabilized cyclic response that would otherwise be obtained from a cycle-by-cycle elastic-plastic FEA. The Twice-Yield method is used to evaluate the load range conditions which occur between any two load states from the stabilized cyclic structural response. The rigorous implementation of the Twice-Yield method requires special handling of material properties. In particular, the method requires the average of the properties corresponding to the two load states. This paper documents a detailed technical basis of the Twice-Yield method’s implementation in Abaqus including the special handling of material properties. An assessment of the Twice-Yield method is performed based on analyzing a thermally shocked stepped pipe. Included in the assessment are comparisons of the cycle-by-cycle elastic-plastic FEA results and the Twice-Yield method elastic-plastic FEA results. The comparisons show the efficacy of the Twice-Yield method as a viable cyclic elastic-plastic analysis method.
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Sva¨rd, Bjo¨rn, Jan-Anders Larsson, Philip Ma˚rtensson, and Bjo¨rn Lundin. "Experiences From Structural Dynamic Analysis Projects of BWR Plants Within the Scope of Power Uprate Projects Using FEA." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-30189.
Повний текст джерелаАнотація:
During recent years, power-uprate projects have been executed at several BWR-units in Sweden. As part of these projects, structural verification of the safety-related buildings as well as the new and old internal parts of the reactor pressure vessel, RPV, has been performed. In this document, some experiences will be presented from structural dynamic verification, using finite element analysis, FEA, within the scope of these power uprate projects. From this work, a number of conclusions can be drawn. Global models with dense meshes can successfully be used for a broad range of applications. Today, large FEA-models can be used efficiently, e.g. in global vibration and structural verification analyses, if suitable dynamic analysis methods are used. There can be strong dynamic interactions between the containment, fluids, the RPV and RPV-internals. Stress calculation and evaluation can be executed efficiently on large models. The structural models can with advantage be re-utilized in future projects.
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Wa¨stberg, Stig, Henryk Pisarski, and Ba˚rd Nyhus. "Guidelines for Engineering Critical Assessments for Pipeline Installation Methods Introducing Cyclic Plastic Strain." In ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/omae2004-51061.
Повний текст джерелаАнотація:
Conventional flaw assessment procedures are not explicitly developed for situations with large cyclic plastic strains, e.g. for pipelines installed by the Reeling method, and if used indiscriminately may give un-reliable results. In order to resolve this dilemma DNV, TWI and Sintef conducted a Joint Industry Project (Fracture Control for Installation Methods Introducing Cyclic Plastic Strain – Development of Guidelines for Reeling of Pipelines) to provide guidelines on testing and assessment procedures that can be employed by the industry. The project included Materials Testing, FEM Analyses and Validation Testing of Pipe Segments as well as Full Scale Pipes. This paper summarizes the Guideline document that was developed in the project.
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Ross, Michael, and Wim Fuls. "Development of a Dynamic Turbine Expansion Model Using a Paired Thermofluid and FEA Methodology." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-78258.
Повний текст джерелаАнотація:
Abstract With increased pressure for conventional coal-fired power plants to adopt a flexible operating principle, an increased need for computationally inexpensive thermal and structural turbine models has been observed. This paper documents the formulation of a paired thermofluid and FEA turbine modelling methodology to predict the radial and axial clearances within a 600MW candidate steam turbine during a full cold start procedure. This study formulates a method for sizing and modelling a representative turbine with limited OEM input through the implementation of the Nozzle Analogy theory for axial, multistage steam turbines. Following the development of a full turbine process model and representative 3D FEA turbine model, a successful validation of key turbine temperatures and differential expansions was carried out using real-world plant data within a high level of accuracy. The modelling methodology presented a computationally inexpensive method to predict internal turbine temperature boundaries as well as the structural behaviour of turbine components under transient loads, and proved invaluable in a thorough understanding of flexible turbine operation.
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Chaduvula, Siva C., Mikhail J. Atallah, and Jitesh H. Panchal. "sFEA: A Lightweight, Scalable, and Secure Finite Element Analysis Technique." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-85566.
Повний текст джерелаАнотація:
Designers need a way to overcome information related risks, including information leakage and misuse from their own collaborators during a collaborative product realization process. Existing cryptographic techniques aimed at overcoming these information related risks are computationally expensive and slow even for moderate problem sizes, and legal approaches (e.g., the use of non-disclosure agreements) are not effective. The computational practicality problem is particularly pronounced for simulation computations like finite element analysis (FEA), that involve both a geometric partitioning (meshing) and computations of cubic time complexity. In this paper, we propose a technological approach that enables designers to perform simulations, such as FEA computations, without the need for revealing their information to anyone, including their design collaborators. We demonstrate our approach using secure finite element analysis (sFEA) which enables designers to perform FEA without having to reveal structural/material information to their counterparts even though the computed answer depends on all the collaborators’ confidential information. We build sFEA using computationally efficient protocols implementing a secure co-design framework. One of our findings is that the most natural implementations of sFEA, using existing protocols, suffer from limited scalability. To overcome these limitations, we propose strategies that help improve the scalability of sFEA. We document and discuss the experiments we conducted to determine the computational overhead imposed by sFEA. The results indicate that the computational burden imposed by sFEA makes it challenging for large-scale FEA — our scheme significantly increases the problem sizes that can be handled when compared to implementations using previous algorithms and protocols, but large enough problem sizes will swamp our scheme as well (in some sense this is unavoidable because of the cubic nature of the FEA time complexity). This work is another step towards opening up new avenues for improving the way information is exchanged in collaborative simulation computations such as FEA.
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Lejeune, Hubert, and Yann Ton That. "Account for Metal to Metal Contact Between Gasket Centering Ring and Flange Facing in Calculation Using the XP CEN\TS 1591-3 Method: Comparison With Other Analytical Method and Finite Element Analysis." In ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28167.
Повний текст джерелаАнотація:
The european standard EN1591-1 [1], initially published in 2001, defines a calculation method for bolted gasketed circular flanges, alternative to the TAYLOR-FORGE method, used as the basic method in most codes. In 2007, a new part, XP CEN/TS 1591-3 [2], has been added to the EN1591 series. This technical specification enables to take into account the Metal to Metal Contact (MMC), appearing inside the bolt circle on some assemblies. Due to a lack of industrial feedback and detailed validation, this document has not been raised to the standard status. In that context, under the request of its Pressure Vessel and Piping commission, CETIM has performed a study comparing this calculation method to Finite Element Analysis (FEA) on several industrial configurations. After a description of the XP CEN/TS 1591-3 calculation method, the major results obtained for spiral wound gasketed joints where MMC appears between centering ring and flange facing are presented and compared with FEA results. Moreover, results obtained with other classical analytical calculation methods as TAYLOR FORGE and EN1591-1 on the same Bolted Flange Connections (BFC) configuration are also analysed and compared to XP CEN/TS 1591-3 results.
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Pontaza, Juan P., Mohan Kotikanyadanam, Piet Moeleker, Raghu G. Menon, and Shankar Bhat. "Fairing Evaluation Based on Numerical Simulation." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83883.
Повний текст джерелаАнотація:
It is well established that strakes are effective at suppressing vortex-induced vibrations (VIV). Fairings are an attractive alternative to helical strakes, because they are a low drag VIV suppression solution. The paper presents an evaluation of a fairing design, based on numerical simulations — to be complemented at a later stage with current tank testing. This paper documents the computational fluid dynamics (CFD) and finite element analysis (FEA) of the evaluation: (1) 3-D CFD in the laboratory scale: 4.5 inch pipe, 3 ft/s current speed, (2) 3-D CFD in the full scale: 14 inch riser, 4 knots current speed, and (3) 3-D FEA of the full-scale fairing module latching mechanism, under service loads corresponding to 4 knots current speed. The analysis results show that the fairing design (1) is effective at suppressing VIV, (2) yields a low drag coefficient (0.52 at Re ∼ 106), and (3) its latching mechanism is adequate for use in calm sea states with 4 knots current speeds.
Звіти організацій з теми "FEMA DOCUMENT"
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Lew, H. S. Supporting document for rehabilitation cost estimates of FEMA existing buildings. Gaithersburg, MD: National Institute of Standards and Technology, 1999. http://dx.doi.org/10.6028/nist.ir.6315.
Повний текст джерела
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McKinnon, Mark B., and Daniel Madrzykowski. Four Firefighters Burned in Residential House Fire - Georgia. UL's Fire Safety Research Institute, June 2022. http://dx.doi.org/10.54206/102376/gekk4148.
Повний текст джерелаАнотація:
On September 3, 2018, two career Fire Lieutenants and two career Firefighters suffered burn injuries as a result of a residential structure fire. On September 10, 2018, personnel representing several other fire departments in the area, including a member of the Fire Safety Research Institute (FSRI) Advisory Board visited the fire scene to document the incident and collect material samples from the structure. The narrative and analysis presented in this report rely on the photographs and evidence collected on September 10, 2018, dispatch transcript [5] and videos recorded at the time of the incident, and interviews conducted by a local investigator between September 3, 2018 and September 7, 2018 with fire service personnel involved in the incident and the resident of the structure [6]. The LaGrange Fire Department invited FSRI to study this incident as part of FSRI’s Near-Miss Project which is supported by a DHS/FEMA Assistance to Firefighters Grant. The goal of this project is to enhance the safety and situational awareness of the fire service by applying fire dynamics research results to near-miss or line of duty injury fire incidents. By identifying factors that contributed to the incident, perhaps future incidents may be prevented. FSRI’s analysis of this incident will apply research results and utilize fire research tools, such as computer fire models, to examine key fire phenomena and tactical outcomes. This report will explain the incident, what occurred, why it occurred, and what can be done differently in the future to result in a more favorable outcome
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Vail, Kylin, Bret Lizundia, David Welch, and Evan Reis. Earthquake Damage Workshop (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/plbd5536.
Повний текст джерелаАнотація:
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 6 (WG6): Interaction with Claims Adjustors & Catastrophe Modelers and focuses on a damage workshop effort undertaken to provide repair estimates of representative damaged single-family wood-frame case study buildings to compare the differences in costs between houses with and without retrofits to cripple walls and sill anchorage. At the request of the CEA, 11 experienced claims adjustors from insurance companies volunteered to provide the estimates. Electronic cost estimation files for each case study building were developed by the PEER–CEA Project Team using the Verisk Xactware Xactimate X1 platform and provided to the claims adjustors to complete their estimates. These adjustor estimates served as the baseline for comparison against the FEMA P-58 [FEMA 2012] methodology used on the project for loss estimation. The term “damage workshop effort” is used to emphasize that the scope of work included not just a successful workshop meeting, but the broader development of a damage description package describing case studies and associated Xactimate descriptions before the workshop meeting and revisions after it, two rounds of estimates and survey question responses by adjustors, interpretation and clarification of the estimates for consistency, and synthesizing of estimate findings and survey responses into conclusions and recommendations. Three building types were investigated, each with an unretrofitted and a retrofitted condition. These were then assessed at four levels of damage, resulting in a total of 24 potential scenarios. Because of similarities, only 17 scenarios needed unique Xactimate estimates. Each scenario was typically estimated by three to five adjustors, resulting in a final total of 74 different estimates.
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Porter, Ben. FEMC Field Standards of Practice (2023). Forest Ecosystem Monitoring Cooperative, April 2023. http://dx.doi.org/10.18125/69327f.
Повний текст джерелаАнотація:
The FEMC is firmly committed to practicing the principles of Diversity, Equity, Inclusion, and Justice (DEIJ). We believe that this document is made complete by incorporating DEIJ principles into all aspects of the field program. We recognize that we still have so much learning to do in this sphere, as individuals and as an organization, and therefore we are committed to modifying this document as frequently as needed to reflect that.
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Schiller, Brandon, Tara Hutchinson, and Kelly Cobeen. Cripple Wall Small-Component Test Program: Dry Specimens (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/vsjs5869.
Повний текст джерелаАнотація:
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measures and documents seismic performance of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Three primary tasks support the earthquake loss-modeling effort. They are: (1) the development of ground motions and loading protocols that accurately represent the diversity of seismic hazard in California; (2) the execution of a suite of quasi-static cyclic experiments to measure and document the performance of cripple wall and sill anchorage deficiencies to develop and populate loss models; and (3) nonlinear response history analysis on cripple wall-supported buildings and their components. This report is a product of Working Group 4: Testing, whose central focus was to experimentally investigate the seismic performance of retrofitted and existing cripple walls. This present report focuses on non-stucco or “dry” exterior finishes. Paralleled by a large-component test program conducted at the University of California, Berkeley (UC Berkeley) [Cobeen et al. 2020], the present report involves two of multiple phases of small-component tests conducted at University of California San Diego (UC San Diego). Details representative of era-specific construction–specifically the most vulnerable pre-1960s construction–are of predominant focus in the present effort. Parameters examined are cripple wall height, finish style, gravity load, boundary conditions, anchorage, and deterioration. This report addresses all eight specimens in the second phase of testing and three of the six specimens in the fourth phase of testing. Although conducted in different testing phases, their results are combined here to co-locate observations regarding the behavior of all dry finished specimens. Experiments involved imposition of combined vertical loading and quasi-static reversed cyclic lateral load onto eleven cripple walls. Each specimen was 12 ft in length and 2-ft or 6-ft in height. All specimens in this report were constructed with the same boundary conditions on the top, bottom, and corners of the walls. Parameters addressed in this report include: dry exterior finish type (shiplap horizontal lumber siding, shiplap horizontal lumber siding over diagonal lumber sheathing, and T1-11 wood structural panels), cripple wall height, vertical load, and the retrofitted condition. Details of the test specimens, testing protocol (including instrumentation), and measured as well as physical observations are summarized. Results from these experiments are intended to support advancement of numerical modeling tools, which ultimately will inform seismic loss models capable of quantifying the reduction of loss achieved by applying state-of-practice retrofit methods as identified in FEMA P-1100 Vulnerability-Base Seismic Assessment and Retrofit of One- and Two-Family Dwellings.
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Budzich, Jeffrey. PR-685-184506-R08 Field Validation of VIV Initiation Within Waterways. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2022. http://dx.doi.org/10.55274/r0012215.
Повний текст джерелаАнотація:
The purpose of this document is to compare a pipeline's natural frequencies obtained from finite element analysis (FEA) and those derived from the vibration data obtained in the field. The FEA model was developed from inputs such as elevation of pipeline's centerline, elevation of ground, properties of soil (assumed), geometry of the pipeline cross section, intermediate pipe supports (if any) and loading. Field data were obtained from accelerometer installed on the pipeline. Note this effort is one component of the larger multifaceted Modernize the Assessment of Pipeline Water Crossings project, and a continuation of Phase B1(Determination of Additional Hydrotechnical threats.
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Schiller, Brandon, Tara Hutchinson, and Kelly Cobeen. Cripple Wall Small-Component Test Program: Wet Specimens I (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/dqhf2112.
Повний текст джерелаАнотація:
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 4: Testing and focuses on the first phase of an experimental investigation to study the seismic performance of retrofitted and existing cripple walls with sill anchorage. Paralleled by a large-component test program conducted at the University of California [Cobeen et al. 2020], the present study involves the first of multiple phases of small-component tests conducted at the UC San Diego. Details representative of era-specific construction, specifically the most vulnerable pre-1960s construction, are of predominant focus in the present effort. Parameters examined are cripple wall height, finish materials, gravity load, boundary conditions, anchorage, and deterioration. This report addresses the first phase of testing, which consisted of six specimens. Phase 1 including quasi-static reversed cyclic lateral load testing of six 12-ft-long, 2-ft high cripple walls. All specimens in this phase were finished on their exterior with stucco over horizontal sheathing (referred to as a “wet” finish), a finish noted to be common of dwellings built in California before 1945. Parameters addressed in this first phase include: boundary conditions on the top, bottom, and corners of the walls, attachment of the sill to the foundation, and the retrofitted condition. Details of the test specimens, testing protocol, instrumentation; and measured as well as physical observations are summarized in this report. In addition, this report discusses the rationale and scope of subsequent small-component test phases. Companion reports present these test phases considering, amongst other variables, the impacts of dry finishes and cripple wall height (Phases 2–4). Results from these experiments are intended to provide an experimental basis to support numerical modeling used to develop loss models, which are intended to quantify the reduction of loss achieved by applying state-of-practice retrofit methods as identified in FEMA P-1100, Vulnerability-Base Seismic Assessment and Retrofit of One- and Two-Family Dwellings.
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Martín, A., L. Cirrottola, A. Froehly, R. Rossi, and C. Soriano. D2.2 First release of the octree mesh-generation capabilities and of the parallel mesh adaptation kernel. Scipedia, 2021. http://dx.doi.org/10.23967/exaqute.2021.2.010.
Повний текст джерелаАнотація:
This document presents a description of the octree mesh-generation capabilities and of the parallel mesh adaptation kernel. As it is discussed in Section 1.3.2 of part B of the project proposal there are two parallel research lines aimed at developing scalable adaptive mesh refinement (AMR) algorithms and implementations. The first one is based on using octree-based mesh generation and adaptation for the whole simulation in combination with unfitted finite element methods (FEMs) and the use of algebraic constraints to deal with non-conformity of spaces. On the other hand the second strategy is based on the use of an initial octree mesh that, after make it conforming through the addition of templatebased tetrahedral refinements, is adapted anisotropically during the calculation. Regarding the first strategy the following items are included:
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Danican(archived), Li. PR218-173602-R01 Assessment of Fitness-for-Service for Crack-within-Corrosion Anomalies. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), May 2020. http://dx.doi.org/10.55274/r0011675.
Повний текст джерелаАнотація:
Continuous crack defects in corroded areas of pipe have been identified as potential cause failures and significant accidents. PRCI was tasked with providing a model to pipeline operators with detailed step-by-step procedures for evaluating the effect of interacting corrosion and crack threats on the integrity of pipelines. There are several existing assessment methodologies for different types of anomaly such as blunt type and crack-like type. The predicted failure pressure PFP results from existing assessment methods were compared and reviewed in this research. Finite Element Analysis (FEA) is a well-documented tool for the accurate assessment of crack-in-corrosion (CIC). Hence, FEA was used in this research to conduct the PFP assessment the results of which were verified with burst tests performed at the Kiefner laboratory as well as data from previous PRCI research: PR-186-113600, Grinding Limits for Repair of SCC on Operating Pipelines (see Ref 18). Additionally, data analytics methodology was used in conjunction with FEA results to develop a relationship between stress intensity and CIC geometry and material properties. The resultant data-analytics derived equation was subsequently verified against burst test results taken from Hosseini's 2010 publication (see Ref 3 and Ref 4).
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Schiller, Brandon, Tara Hutchinson, and Kelly Cobeen. Cripple Wall Small-Component Test Program: Wet Specimens II (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/ldbn4070.
Повний текст джерелаАнотація:
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 4 (WG4): Testing, whose central focus was to experimentally investigate the seismic performance of retrofitted and existing cripple walls. This report focuses stucco or “wet” exterior finishes. Paralleled by a large-component test program conducted at the University of California, Berkeley (UC Berkeley) [Cobeen et al. 2020], the present study involves two of multiple phases of small-component tests conducted at the University of California San Diego (UC San Diego). Details representative of era-specific construction, specifically the most vulnerable pre-1960s construction, are of predominant focus in the present effort. Parameters examined are cripple wall height, finish style, gravity load, boundary conditions, anchorage, and deterioration. This report addresses the third phase of testing, which consisted of eight specimens, as well as half of the fourth phase of testing, which consisted of six specimens where three will be discussed. Although conducted in different phases, their results are combined here to co-locate observations regarding the behavior of the second phase the wet (stucco) finished specimens. The results of first phase of wet specimen tests were presented in Schiller et al. [2020(a)]. Experiments involved imposition of combined vertical loading and quasi-static reversed cyclic lateral load onto ten cripple walls of 12 ft long and 2 or 6 ft high. One cripple wall was tested with a monotonic loading protocol. All specimens in this report were constructed with the same boundary conditions on the top and corners of the walls as well as being tested with the same vertical load. Parameters addressed in this report include: wet exterior finishes (stucco over framing, stucco over horizontal lumber sheathing, and stucco over diagonal lumber sheathing), cripple wall height, loading protocol, anchorage condition, boundary condition at the bottom of the walls, and the retrofitted condition. Details of the test specimens, testing protocol, including instrumentation; and measured as well as physical observations are summarized in this report. Companion reports present phases of the tests considering, amongst other variables, impacts of various boundary conditions, stucco (wet) and non-stucco (dry) finishes, vertical load, cripple wall height, and anchorage condition. Results from these experiments are intended to support advancement of numerical modeling tools, which ultimately will inform seismic loss models capable of quantifying the reduction of loss achieved by applying state-of-practice retrofit methods as identified in FEMA P-1100,Vulnerability-Base Seismic Assessment and Retrofit of One- and Two-Family Dwellings.