Academic literature on the topic 'Mechanical Integrity Test (MIT)'
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Journal articles on the topic "Mechanical Integrity Test (MIT)"
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Davis, Allen G. "Assessing Reliability of Drilled Shaft Integrity Testing." Transportation Research Record: Journal of the Transportation Research Board 1633, no. 1 (January 1998): 108–16. http://dx.doi.org/10.3141/1633-14.
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The reliability of an engineering system can be described as the degree of confidence in the system performing as it is designed or intended to do. This can be assessed by a purely subjective, “gut feeling” reaction from the engineer making judgments based on the test results, or it can be expressed mathematically by considering the reliability of individual system components, together with their relative effects on the performance of the total system. Nondestructive testing (NDT), when used in the quality control of drilled shafts, can be viewed from two extremes: either NDT helps engineers confirm that their design and intended performance criteria are being met, or NDT checks that the contractor has supplied the owner with the product for which the owner has paid (material quality, minimal geometric requirements, etc.). NDT methods currently available are more suited to the first scenario (performance specification). This is supported by analysis of the parameters controlling NDT results and by experience in the United States and in the rest of the world.
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Muñiz-Calvente, Miguel, and Alfonso Fernández-Canteli. "Special Issue: Probabilistic Mechanical Fatigue and Fracture of Materials." Materials 13, no. 21 (October 31, 2020): 4901. http://dx.doi.org/10.3390/ma13214901.
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When designing structural and mechanical components, general structural integrity criteria must be met in order to ensure a valid performance according to its designed function, that is, supporting loads or resisting any kind of action causing stress and strains to the material without catastrophic failure. For these reasons, the development of solutions to manage the test conditions, failure mechanism, damage evolution, component functionalities and loading types should be implemented. The aim of this Special Issue “Probabilistic Mechanical Fatigue and Fracture of Materials” is to contribute to updating current and future state-of-the-art methodologies that promote an objective material characterization and the development of advanced damage models that ensure a feasible transferability from the experimental results to the design of real components. This is imbricated in some probabilistic background related to theoretical and applied fracture and fatigue theories, and advanced numerical models applied to some real application examples.
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Haffke, Marcin, Matthias Pahn, Catherina Thiele, and Szymon Grzesiak. "Experimental Investigation of Concrete Sandwich Walls with Glass-Fiber-Composite Connectors Exposed to Fire and Mechanical Loading." Applied Sciences 12, no. 8 (April 12, 2022): 3872. http://dx.doi.org/10.3390/app12083872.
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Precast concrete sandwich panels (PCSPs) are known for their good thermal, acoustic and structural properties. Severe environmental demands can be met by PCSPs due to their use of highly thermally insulating materials and non-metallic connectors. One of the main issues limiting the wider use of sandwich walls in construction is their unknown fire resistance. Furthermore, the actual behaviour of connectors and insulation in fire in terms of their mechanical performance and their impact on fire spread and the fire resistance of walls is not fully understood. This paper presents an experimental investigation on the structural and thermal behaviour of PCSPs with mineral-wool insulation and glass-fiber-reinforced polymeric bar connectors coupling two concrete wythes. Three full-size walls were tested following the REI certification test procedure for fire walls under fire and vertical eccentric and post-fire mechanical impact load. The three test configurations were adopted for the assessment of the connectors’ fire behaviour and its impact on the general fire resistance of the walls. All the specimens met the REI 120-M criteria. The connectors did not contribute to the fire’s spread and the integrity of the walls was maintained throughout the testing time. This was also confirmed in the most unfavourable test configuration, in which some of the connectors in the inner area of the wall were significantly damaged, and yet the structural connection of the concrete wythes was maintained. The walls experienced heavy heat-induced thermal bowing. The significant contribution of connectors to the stiffness of the wall during fire was observed and discussed.
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Li, Qiong, and Carol A. Rubin. "Virtual Prototype Design and Test-Simplifying the CAD/Analysis Interface." Applied Mechanics and Materials 284-287 (January 2013): 3473–76. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.3473.
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The design of mechanical structural parts is now predominantly a digital process. As an important element of the virtual design cycle, these parts must be tested for their structural integrity using finite element analysis (FEA) software. However, the interface between CAD and FEA is imperfect. The process of preparing CAD models for FEA consumes a great deal of the stress analyst’s time. Existing “automatic” CAD to FEA translators tend to treat all part features as “solid”; this leads to longer computation times and less accurate results for features that can be better characterized as “thin” or “long.” In addition, many features of CAD parts (e.g. fillets and chamfers) are important for their size and shape in the manufactured product, but have relatively little impact on the strength of the part and needlessly complicate the stress analysis—these features are usually removed by the analyst prior to FEA; they may need to be evaluated with additional analyses to test if it is safe to remove them. The Automatic CAD-FEA Interface Project (ACFI), is developing algorithms to make the translation from CAD to FEA seamless and automatic; these algorithms are based on mathematical theory and the principles of theoretical mechanics. This paper presents the latest ACFI advances for (i) automatically evaluating and reworking three dimensional CAD part geometries to prepare them for finite element meshing, (ii) exporting the revised geometries to a preprocessor, and (iii) identifying element type to be associated with each feature geometry. The algorithms used in this work approximate the medial axis transform (MAT) of the CAD part, a “power shape” that represents the three-dimensional solid part. This part can then be evaluated for its geometric properties. This approach has been shown to be a robust method for shape interrogation of three dimensional geometries.
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Karolak-Michalska, Magdalena. "Byłe republiki ZSRR wobec aneksji Krymu do Rosji – analiza porównawcza reakcji państw." Studia Gdańskie. Wizje i rzeczywistość XIV (June 3, 2018): 333–48. http://dx.doi.org/10.5604/01.3001.0015.5411.
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The aim of the article is to analyze the reaction of the former USSR towards the annexation of the Crimea to Russia. The author points out that the crisis Ukrainian-Russian met a series of reactions, which were particularly important response to those located in the immediate vicinity of Russia. Violation of the integrity of the borders of Ukraine provoked a wave of unrest in the region of the former republics of the communist empire, which faced a need to respond to the rapidly changing political reality. Analyzing the responses of individual countries, the author concludes that either option of the conflicting parties, it was the first test for the condition of the political and economic policies of particular countries, and secondly verified relations with Russia, revealing interdependencies and concerns, and also gave Kremlin authorities with information on how much they can afford to continue violating international order.
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Abbassi, Amira, Ali Trabelsi, Sofien Akrichi, and Noureddine Ben Yahia. "Assessment of cylindricity and roughness tolerances of holes drilled in marble using multiple regression and artificial intelligence." Advances in Mechanical Engineering 13, no. 8 (August 2021): 168781402110406. http://dx.doi.org/10.1177/16878140211040647.
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The Calacatta-Carrara marble is widely used due to its excellent physico-chemical characteristics and attractive aspect. However, the sensitivity of this materiel, when performing delicate manufacturing operations, presents for the engineers a hard challenge to overcome. This issue is mainly encountered with complex shapes of parts, for which it is difficult to preserve surface integrity and avoid geometric defects. The paper aims at finding out optimal drilling parameters of cutting in the Calacatta-Carrara white marble material, in order to minimize the holes cylindricity (HC) and surface roughness (HR) using six controlled operating factors, namely, the rotation speed ( N), the feed speed ( F), the drill bit diameter (BD), the drill bit height (BH), the number of pecking cycles ( P), and the drilling depth (DD). The experimental design uses a [Formula: see text] fractional factorial plan that is replicated once for cost consideration. The optimization process, that is, minimum cylindricity and roughness tolerances, is carried out using the Gray Relational Analysis (GRA) technique. Numerical modeling of machining parameters is performed using Multi-Layer Perceptron Artificial Neural Network (MLP ANN) and Multiple Regression Model (MR) to predict surface quality. For the sake of completeness these two models were compared in terms of fitness and predictability. The models were assessed statistically using the correlation coefficient. Results showed that either solution predicts a roughness tolerance which is in good agreement with the test data (both R-sq.(adj.) and R-sq.(pred.) >94%). However, the holes cylindricity tolerance response was shown to be superior with MLP-ANN model (R-sq.(adj.) 50.64% and R-sq.(pred.) 48.67%). The GRA analysis shows that minimum cylindricity and roughness are met when N and F are set high, BD and BH low, P high and DD low.
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Salem, Ahmed Z. "Using Glass Mat Thermoplastic as Automotive Bumper’s Material to Enhance Pedestrian Safety." Advanced Materials Research 875-877 (February 2014): 455–61. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.455.
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The usage of softer systems in automotive bumper is a growing trend currently especially to serve the pedestrians safety function. The term softer here does refer to the bumper system’s dynamic behavior rather than its material’s flexure or tension modules. However, the usage of such softer systems would raise issues of structural integrity of the bumper during crash. There is a strong drive currently to adopt materials such as glass mat thermoplastic (GMT), high-strength sheet molding compound (SMC) for the bumper material and plastic polypropylene (PEP) for the bumper holders [1, 2, 3] in this regard. While both the GMT and SMC do enhance the pedestrian safety condition, they both show plastic deformation at crash, even in low-speed scenarios [2, 3]. The PEP holders react only as shock absorbers and act like mechanical fuses to be destroyed in car crash, preventing the main bumper from being damaged [4]. In this paper, we propose a remedy for this problem by changing the common system that the GMT and SMC materials are usually fitted at. We propose coating the bumper beam with a Rubber padding layer that eliminates the plastic strain at low-speed crash. We also examine the behavior of the PEP during such crash scenarios. We present here the results of a low-speed head-on automotive-pedestrian crash simulation scenario for these material models, using the explicit dynamics finite element code LS-DYNA within ANSYS integration setting. A simplified parameterized finite element model of the Ford Crown Victoria car’s bumper form is used in several crash simulations that are carried out to test the validity of this modified bumper system. Based on the results of these tests, we show that, applying the Rubber coating material for the GMT and SMC bumper beams eliminates the plastic stains at low-speed crash.
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Lee, J. H., S. K. Hong, H. C. Hur, and Y. J. Choi. "Improvement of the resolution in direct membrane integrity test by controlling solution surface tension." Water Science and Technology 59, no. 11 (June 1, 2009): 2205–11. http://dx.doi.org/10.2166/wst.2009.251.
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Membrane-based treatment technologies have been introduced as a promising tool for the removal of water-borne pathogens. To ensure successful application of membrane processes, the integrity of the membrane system should be maintained. Related with evaluation of the membrane integrity, USEPA guidance recommends pressure-based membrane integrity (MIT). Based on the bubble point theory, the ability of detecting smallest integrity breakage during the MIT is defined as “Resolution”. However, the response to remarkably small breach demands significantly high initial test pressure of the pressure decay test. In this study, the surface tension of the test liquid was controlled to improve the resolution without increasing the corresponding test pressure. Three common chemicals were chosen to control the solution surface tension. It is concluded that 0.1 M of the citric acid can decrease the initial test pressure significantly for the same pore size. Subsequently, the improvement of the resolution with controlled surface tension was confirmed by the results of pressure decay test and marker test.
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Urbano, Jose, Andrej Golowin, Stefan Löhnert, and Dieter Bestle. "Mechanical Integrity of Steel Discs with Corrosion Pits." MATEC Web of Conferences 165 (2018): 04012. http://dx.doi.org/10.1051/matecconf/201816504012.
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Currently, prediction of crack initiation by corrosion pits is only possible by assuming regular geometrical shapes, such as semi-spheres or semi-ellipsoids. Moreover, typical fatigue life diagrams associate the crack initiation life with geometrical features, such as pit depth or aspect ratio, often leading to unsatisfactory correlations due to high pit shape variability and data scatter. In the context of blade-disc fixation in aero engine turbines, this limitation translates into highly conservative life estimations. Therefore, a new crack initiation predictor is formulated based on experimental testing and numerical analysis of 28 artificial corrosion pits. A low-cycle fatigue test campaign is conducted using three-point bending test specimens to simulate maximum takeoff operation conditions of the aero engine and the associated loading of the blade root designed as firtree. An artificial pit is located at the critical point of each test specimen, respectively. The prediction criterion is based on finite element analysis and is formulated as the lowest plastic strain of a plastic region with a certain volume in the corrosion pit. This reference volume is varied until an optimum correlation with experimental crack initiation life is obtained. The criterion shows a superior correlation with crack initiation life compared to pure geometrical parameters such as pit depth.
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Hossiep, Rüdiger, and Sabine Bräutigam. "Tests und Tools." Zeitschrift für Personalpsychologie 6, no. 2 (April 2007): 85–90. http://dx.doi.org/10.1026/1617-6391.6.2.85.
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Zusammenfassung. Vorgestellt wird das IBES (Inventar berufsbezogener Einstellungen und Selbsteinschätzungen), das erste publizierte deutschsprachige Verfahren der Gattung “Integrity Test”. Ziel des Instrumentes ist die Vorhersage kontraproduktiven Verhaltens in Unternehmen (z. B. Absentismus, Diebstahl, Aggression). Die Konstruktion erfolgte in enger Anlehnung an Inhalte prominenter amerikanischer Integrity Tests. Das IBES besteht aus einem einstellungsorientierten Teil mit 60 Items, die den vier Skalen “Vertrauen”, “Geringe Verbreitung unerwünschten Verhaltens”, “Nicht-Rationalisierung” und “Verhaltensabsichten” zugeordnet sind sowie einem eigenschaftsorientierten Teil mit 55 Items, unterteilt in die fünf Skalen “Gelassenheit/Selbstwertgefühl”, “Zuverlässigkeit/Voraussicht”, “Vorsicht”, “Zurückhaltung” und “Konfliktmeidung”. Die Anwendbarkeit des Verfahrens in der Praxis wird insbesondere vor dem Hintergrund der Datenbasis und des Itemmaterials kritisch diskutiert.
Dissertations / Theses on the topic "Mechanical Integrity Test (MIT)"
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Réveillère, Arnaud. "The development of the concern for tightness in the salt cavern industries, of accurate tightness test techniques and of the concept of Mechanical Integrity Tes." Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS564.
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Les cavités salines ont été initialement un sous-produit de l'extraction industrielle de sel. Dans les années 40, elles ont commencé à être utilisées pour y stocker des hydrocarbures. Il y a aujourd'hui 2000 cavités salines dans le monde stockant des fluides liquides, gazeux ou supercritiques. La nécessité de tester l'étanchéité des cavités de stockage est venue avec leur développement. Une grande diversité de techniques a été proposée, variant dans le temps, selon les sociétés et les pays. Par ailleurs, plusieurs critères d'acceptation de ces tests ont été, et sont encore, utilisés. Si les premiers critères ont tenté de relier le succès ou l'échec d'un test à de possibles impacts, l'industrie a préféré utiliser des critères qui ont démontré leur applicabilité et leur efficacité via un historique limité d'accidents lorsqu'ils étaient appliqués. Ce travail présente toutes ces initiatives et leur contexte historique. Les incertitudes de mesure sont propagées afin de permettre de comparer la précision des principaux tests. Inventé dans les années 70, le "Mechanical Integrity Test" azote/saumure est progressivement devenu la référence des tests d'étanchéité de cavités salines. La comparaison des précisions montre qu'il est excellent. Parmi les options de stockage massif, les cavités salines ont aujourd'hui une propriété singulière: leur étanchéité peut être testée très précisémentSalt caverns started being produced as a by-product of the salt production industry. In the 1940s, these caverns started being used for storage of hydrocarbons. There are now 2000 salt caverns globally storing liquid, gaseous or supercritical fluids. The necessity to test the tightness of the storage caverns came along with their development. A large variety of techniques have been proposed, varying over time, companies and countries. In addition, several acceptance criteria of these tests have been, and are still, used. While first attempts were to relate a fail/pass criteria to possible impacts, the industry rather relied on criteria that have shown their applicability and their effectiveness through a track record of a limited number of accidents when applied. This work presents all these initiatives and their historical context. Measurements uncertainties are propagated in order to enable to compare the accuracies of the main tightness test techniques. Invented in the 1970s, the nitrogen/brine "Mechanical Integrity Test" progressively became the reference tightness test technique for salt caverns. The comparison of tests accuracies shows it is excellent. Among massive storage options, salt caverns now have a singular property: their tightness can be tested very accurately
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Samosky, Joseph T. (Joseph Thomas). "Spatially-localized correlation of MRI and mechanical stiffness to assess cartilage integrity in the human tibial plateau." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/31105.
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Thesis (Ph.D.)--Harvard--Massachusetts Institute of Technology Division of Health Sciences and Technology, 2002.Includes bibliographical references (p. 216-225).
Osteoarthritis is a painful degenerative joint disease affecting millions of people in the U.S. The pathogenesis of articular cartilage disease is characterized by softening of cartilage and loss and disruption of constituent macromolecules including proteoglycans and collagen. In current orthopaedic surgical practice, the gold standard for evaluating articular cartilage integrity is the use of a hand probe during arthroscopy. Mechanical probing, however, is invasive and requires anesthesia. Tightly confined areas of the articular surface can be difficult to reach and assess, and manual probing provides a subjective rather than a quantitative assessment of cartilage mechanical integrity. This thesis was motivated by the desire for a noninvasive and nondestructive means to map the variation in mechanical stiffness of an articular surface. Such a method could potentially have application to guiding surgeons during procedures and quantitatively assessing the efficacy of medical and surgical therapies. It could also potentially provide patient-specific, in vivo tissue mechanical property data for surgical simulation and preoperative procedure planning. The macromolecule glycosaminoglycan (GAG) is a significant determinant of cartilage stiffness. GAG content can be assessed noninvasively in vivo and in vitro by an MRI-based technique known as delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), which measures the MRI parameter TI after equilibration with the ionic contrast agent Gd(DTPA)2-. With dGEMRIC, TlGd serves as an index of GAG content: we therefore examined whether cartilage stiffness could be related to dGEMRIC-measured TlGd in samples of human tibial plateaus.
(cont.) We developed an experimental methodology to permit indentation test sites and regions in dGEMRIC scans to be registered with submillimeter accuracy. We found that the load response to focal indentation (a measure of local stiffness) and locally-averaged TlGd were in general highly correlated (Pearson correlation coefficients r = .80, .90, .64, .81 (p < .002) for four different patient samples, 130 total test locations). We further demonstrated that the observed correlation is not a simple consequence of cartilage thickness effects. We observed that the parameters of the stiffness-TIGd relationship differed in some samples between the region of the tibial plateau covered by the meniscus in vivo and the more central region normally in contact with the femoral condyle. This suggests that another factor such as surface architecture or collagen integrity also influences the indentation response of the articular surface.
by Joseph Thomas Samosky.
Ph.D.
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Gregori, Alberto. "Synthesis of Conjugated Polymers and Adhesive Properties of Thin Films in OPV Devices." Thesis, Pau, 2015. http://www.theses.fr/2015PAUU3028/document.
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La production d’énergie avec des cellules photovoltaïques organiques (OPV) est une des applications les plus prometteuses des semi-conducteurs organiques, en raison de leur compatibilité avec les substrats flexibles permettant des produits légers, peu chers et décoratifs. Pendant longtemps, poly(3-hexylthiophène) (P3HT) a été le polymère de choix dans l’OPV combiné au [6,6]-phényl-C61-butanoate de méthyle (PC61BM) comme accepteur. Toutefois, des recherches récentes ont porté sur des polymères avec meilleures absorption et processabilité, qui peuvent assurer des rendements et des durées de vie plus élevés. Des rendements de conversion en puissance (PCE) au-dessus de 11% ont récemment été démontrés. Cette thèse rapporte sur la synthèse et la caractérisation de deux séries de polymères dits à faible bande interdite, LBGs "push-pull" (ou donneur-accepteur), constitués de l'unité donneuse 4,4-bis(2-ethylhexyl)-5,5'-dithieno[3,2-b:2',3'-d]silole (DTS) combinée au 3,6-dithiophén-2-yl-2,5-dihydro-pyrrolo[3,4-c]pyrrole-1,4-dione (DPP) ou au 5,7-di(thiényl)thiéno[3,4-b]pyrazines (DTP), comme unité acceptrice. Toutes les molécules et les polymères ont été caractérisés chimiquement et leur propriétés optoelectroniques, morphologiques et photovoltaïques ont été determinées. La série DTS-DPP a été choisie parce qu'elle est représentative d'un grand nombre de polymères LBG et a fourni un modèle facilement accessible pour évaluer l'importance de la chaîne latérale utilisée sur leur propriétés optoélectroniques et thermiques. Les premières études sur les dispositifs à base de DTS-DPP:PC61BM ont été menées, pour déterminer les propriétés photovoltaïques. Le meilleur dispositif permet d’obtenir un PCE de 1,7% avec JSC de 5,9 mA cm-2, VOC de 0,54 V et FF de 0,58. La série DTS-DTP a été choisie pour la stabilité chimique élevée des deux unités et pour la facilité de substitution des groupes latéraux. La polymérisation a partiellement abouti, en donnant seulement des oligomères. La caractérisation chimique a pu être effectuée, mais leur application dans l’OPV n'a pas été explorée. En termes de stabilité, les mécanismes de défaillance électrique des dispositifs OPV ont été étudiés, montrant une méconnaissance de leur stabilité mécanique. Les contraintes caractéristiques de chaque couche mince présentes dans les cellules solaires organiques constituent la force motrice à l’origine de la délamination des interfaces faibles ou même leur decohésion, causant une perte de l'intégrité et des performances du dispositif. Une technique pour sonder les couches ou les interfaces fragiles dans les cellules solaires polymère:fullerene est présentée. Elle a été développée par l'établissement d'un nouveau set-up pour le test pull-off, développé en utilisant un dispositif à géométrie inverse, de structure verre/ITO/ZnO/P3HT:PC61BM/PEDOT:PSS/Ag. Les dispositifs délaminés ont montré que le point le plus faible est localisé à l'interface AL/HTL, en bon accord avec la littérature. La technique a été étendue en variant les deux couches sensibles, en utilisant differents polymères LBG pour l’AL (PSBTBT et PDTSTzTz) en combinaison avec deux formulations de PEDOT:PSS, CleviosTM HTL Solar à base d'eau et un nouveau HTL Solar 2 à base de solvant organique. Une différence entre la contrainte à la rupture des dispositifs avec différentes combinaisons de AL et HTL est visible, suggérant différents chemins de fracture, tel que confirmé par la caractérisation de surface et qui pourrait être corrélée avec la différence de comportement de la couche active avec les deux formulations de PEDOT:PSS. Une autre voie adoptée, a été d’introduire une couche d’interface de copolymère à blocs amphiphile afin d'améliorer la compatibilité des deux couches. Cette stratégie n'a pas abouti et la nouvelle architecture présente une adhésion réduite. La poursuite de l’amélioration des procédés de fabrication de ces dispositifs pourrait faire de cette nouvelle architecture, une alternative viableOrganic photovoltaic (OPV) devices are one of the most promising applications of organic semiconductors due to their compatibility with flexible plastic substrates resulting in light weight, inexpensive and decorative products. For a long time poly(3-hexylthiophene) (P3HT) has been the polymer of choice in OPV devices in combination with [6,6]-phenyl-C61-butyric acid methylester (PC61BM) as acceptor. However, recent research has focused on polymers with improved absorbance and processability that can ensure higher efficiencies and longer lifetimes (Low BandGap polymers (LBGs)). This has been fully demonstrated with a power conversion efficiency (PCE) above 11%. This thesis reports synthesis and characterization of two series of so-called “push-pull” (or donor-acceptor) LBGs based on the donor unit 4,4′-bis(2-ethylhexyl)-5,5’-dithieno[3,2-b:2′,3′-d]silole (DTS) and either 3,6-dithiophen-2-yl-2, 5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP) or 5,7-di(thienyl)thieno[3,4-b]pyrazines (DTP), as acceptor unit. All π-conjugated molecules and polymers were characterized by chemical investigation and their optoelectronic, morphological, and photovoltaic properties are reported. The DTS-DPP series was chosen because representative of a large number of LBG polymers and provided an easily accessible and useful template to discover the importance of the type of side-chain used on the polymer optoelectronic and thermal properties. First studies on DTS-DPP:PC61BM devices have been conducted, in order to investigate any effect on their photovoltaic properties. The best device obtained had a PCE of 1.7% with JSC of 5.9 mA•cm-2, VOC of 0.54 V and FF of 0.58. The DTS-DTP series was chosen for the high stability of the two units and for the ease of substitution of the side-groups. The synthesis was partially successful and only oligomers were obtained. Nonetheless, chemical characterization was performed but their application in OPV was not explored. In terms of device stability, the electrical failure mechanisms in OPV devices have been investigated, while little is known about their mechanical stability. The characteristic thin film stresses of each layer present in organic solar cells, in combination with other possible fabrication, handling and operational stresses, provide the mechanical driving force for delamination of weak interfaces or even their de-cohesion, leading to a loss of device integrity and performance. A technique to probe weak layers or interfaces in inverted polymer:fullerene solar cells is presented. It was developed by establishing a new set-up for the pull-off test. The technique was developed using inverted device, with the structure glass/ITO/ZnO/P3HT:PC61BM/PEDOT:PSS/Ag. The delaminated devices showed that the weakest point was localized at the active layer/hole transporting layer interface, in good agreement with the literature. The technique was extended varying both sensitive layers, using different p-type low bandgap (co)polymers for the active layer (PSBTBT and PDTSTzTz) in combination with two different PEDOT:PSS formulations, the water based CleviosTM HTL Solar and a new organic solvent based HTL Solar 2. The half-devices produced upon destructive testing have been characterized by contact angle measurement, AFM and XPS to locate the fracture point. A difference in the stress at break for devices made with different combinations of active and hole transporting layers is visible, suggesting different fracture paths, as confirmed by surface characterization and could be correlated to the different behavior of the active layer with the two PEDOT:PSS formulations. Another solution adopted, it had been the introduction of amphiphilic block-copolymer interlayer to enhance the compatibility of the two layers. This strategy was not successful and the new architecture showed reduced adhesion strength. Further development of device processing could make this new architecture a viable alternative
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Hare, Brian. "Evaluation of Packaging Film Mechanical Integrity Using a Standardized Scratch Test." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9796.
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Polymeric packaging films see widespread use in the food packaging industry, and their mechanical integrity is paramount to maintaining product appearance, freshness, and overall food safety. Current testing methods, such as tensile or puncture tests, do not necessarily correlate well with field damages that are observed to be scratch-like. The standardized linearly increasing load scratch test is investigated as a new means of evaluating the mechanical integrity of packaging films.
Mechanical clamp and vacuum fixtures were considered for securing the films to a set of backing materials and tested under various testing rates and film orientation conditions. Film performance was evaluated according to their puncture load. Based on the above study, the vacuum fixture offers the most consistent and meaningful results by providing a more intimate contact between film and backing and minimizing uncontrolled buckling of the film during testing. Additional testing was also carried out on a commercial film to confirm similarity between damage observed in the scratched films and that from the field. The scratch test gives good correlation between field performance and scratch test results on a set of commercial films. The usefulness of the scratch test methodology for packaging film mechanical integrity evaluation is discussed.
Scratch-induced damages on multi-layer commercial packaging films are investigated using cross- and longitudinal-sectioning. Scratch test results show clear distinction between the two tested systems on both the inside and outside surfaces. Microscopy was performed to investigate the feasibility of utilizing this methodology as a tool for packaging film structure evaluation by determining the effect each layer has on the resistance of scratch damages. It is shown that the film showing superior scratch test results also shows significantly better stress distribution through its layers during the scratch test, as well as better layer adhesion during severe deformation. The scratch test shows good ability to provide more in-depth film mechanical integrity testing by allowing for layer-by-layer analysis of damages and layer adhesion after testing.
Books on the topic "Mechanical Integrity Test (MIT)"
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Technisches Englisch-Deutsch Wörterbuch Automobiltechnik Kraftfahrzeugtechnik Luftfahrt kfz-Mechatronik: Technische Fachbegriffe werden mit einer autocomplete-suche / auto-vervollständige suche gefunden. 63500 Seligenstadt, Germany: Verlag Lehrmittel Wagner, 2010.
Find full textBook chapters on the topic "Mechanical Integrity Test (MIT)"
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Bilke, Lars, Thomas Fischer, Dmitri Naumov, Daniel Pötschke, Karsten Rink, Amir Shoarian Sattari, Patrick Schmidt, Wenqing Wang, and Keita Yoshioka. "Code Descriptions." In GeomInt–Mechanical Integrity of Host Rocks, 243–54. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-61909-1_7.
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AbstractThe FFS method (see Sect. 10.1007/978-3-030-61909-1_3) was developed to simulate direct shear tests. To provide a tool for the project work and get things easier done a graphical user interface (GUI) was also created. The GUI simply calls all necessary functions by letting the user either fill form fields or choose input files from the working folder. The rock parameters and the conditions of the direct shear test with the normal stress levels and shear displacements have to be selected. If an experiment is simulated the lab results can be selected as a text file so a visual comparison is possible. The geometry has to be loaded as a point cloud or an artificial surface can be generated. With small modifications the code can do multiple executions using artificial surfaces.
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Lacombe, Alexandra, Yann Landon, Manuel Paredes, Clément Chirol, and Audrey Benaben. "Influence of the Hole Surface Integrity on the Fatigue Strength of an Aluminium Drilled Part." In Lecture Notes in Mechanical Engineering, 34–40. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-70566-4_7.
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AbstractFatigue strengths of aluminium 2024-T351 open-hole specimens drilled by axial and orbital drilling processes are compared. Two drilling diameters (Ø) are studied: 6.35 mm and 9.53 mm. Surface integrity characterization tests are conducted in order to study the link between drilling processes, surface integrity and fatigue life. Fatigue test results show an increase of the fatigue life for specimens drilled by axial drilling for Ø = 9.53 mm and no significant difference in fatigue life between the two drilling processes for Ø = 6.35 mm. Surface integrity results show no impact of the roughness on the fatigue strength but a potential positive influence of the hole microhardness on the fatigue life.
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Muvunzi, Rumbidzai, Ilesanmi Daniyan, Festus Fameso, and Khumbulani Mpofu. "Modelling and Simulation of Pump Impeller Produced Using Fused Deposition Modelling." In Lecture Notes in Mechanical Engineering, 647–56. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-28839-5_73.
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AbstractAdditive Manufacturing (AM) is a key Fourth Industrial Revolution (4IR) technology in which parts are manufactured directly from 3-dimensional models through selective deposition of materials. As a digital technology, AM can be used to produce complex parts that are difficult to make using traditional methods without the need for tooling. Hence, the aim of this study is to investigate the performance of Fused Deposition Modelling (FDM) in the manufacture of pump impellers. This involves performing simulation to test the performance of pump impeller under real-life working conditions at different operating speeds and pressures. The model of the impeller as casted in the FDM process was developed in the complete Abaqus modelling environment. The model part was created as single solid homogenous part with no nodal separations or assembly ties or constraints between the base of the impeller and its blades, in relation to its as-cast manufacturing state. The results obtained showed that extreme operating speeds of up to 1000 rad/s or pressures of 0.22 MPa are not suitable conditions under which the impeller will operate without compromising its efficiency and structural integrity. The study is useful in providing guidance on the application of FDM to produce functional parts. Through the study, the capability of AM as a suitable approach for enabling local sustainable production of spare parts is demonstrated.
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Dallam, Craig B., and Brian K. Damkroger. "Characterization of Welds." In Weld Integrity and Performance, 39–55. ASM International, 1997. http://dx.doi.org/10.31399/asm.tb.wip.t65930039.
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Abstract This article reviews nondestructive and destructive test methods used to characterize welds. The first process of characterization discussed involves information that may be obtained by direct visual inspection and measurement of the weld. An overview of nondestructive evaluation is included that encompasses techniques used to characterize the locations and structure of internal and surface defects, including radiography, ultrasonic testing, and liquid penetrant inspection. The next group of characterization procedures discussed is destructive tests, requiring the removal of specimens from the weld. The third component of weld characterization is the measurement of mechanical and corrosion properties. Following the discussion on the characterization procedures, the second part of this article provides examples of how two particular welds were characterized according to these procedures.
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Dzidic, Sanin, and Aldin Mahmutovic. "A Proposal for Design Model for Determining the Flexural Bearing Capacity of RC Beams Reinforced by Steel with Reduced Modulus of Elasticity." In Advances in Structural Integrity and Failure [Working Title]. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.1002342.
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The design of concrete structures and elements in Europe and wider is conducted according to EN 1992-1-1. Among other design assumptions, the Eurocode 2 assumes the design value of the modulus of elasticity Es of reinforcing steel to be 200 GPa. However, what happens in the RC beam if the actual modulus of elasticity is significantly reduced. Does it affect the flexural bearing capacity of RC beam and to what extent? Another logical question is how to determine the actual flexural bearing capacity of the RC beam reinforced with reinforcing steel with a reduced modulus of elasticity and which design model to use for such determination. This study tries to answer such questions using an experimental approach and assumed calculation model with a comparison of experimental and calculation results. The experimental research from this showed that test RC beams reinforced by steel with reduced modulus of elasticity have significantly reduced flexural capacity in comparison with the designed flexural capacity of beams reinforced by steel with “normal” modulus of elasticity. In this regard, it is recommended to test the mechanical properties of the steel reinforcement prior to the installation at the site and not to rely on the producer’s factory production control certificate only. Additional issues considered in this research are observed effects of the reduced modulus of elasticity of reinforcing bars to Serviceability Limit States (stress limitation, crack width, and deflection control). Answers to such questions can inform decisions if retrofit is needed, is it feasible and if yes—which retrofit method to be used. This study does not discuss the reasons for the reduced modulus of elasticity in reinforcing steel.
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Samal, M. K., and K. S. Balakrishnan. "Experiments on a Ring Tension Setup and FE Analysis to Evaluate Transverse Mechanical Properties of Tubular Components." In Modeling and Simulation Techniques in Structural Engineering, 91–115. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0588-4.ch004.
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Determination of transverse mechanical properties from ring specimens machined from tubular components is not straightforward due to presence of combined tension and bending stresses. Zircaloy tubes as used in nuclear reactors are manufactured through a complicated process of pilgering and heat-treatment and hence, the properties need to be determined in the as-manufactured condition. In this work, the authors perform ring-tensile tests on specimens of Zircaloy pressure tubes of Indian pressurized heavy water reactor in order to carry out integrity assessment of these tubes. As the loading condition in this test imposes both membrane and bending stresses in the cross-section of the ring, 3-D finite element analysis of the test setup was carried out in order to determine material stress-strain curve using an iterative technique. The effect of the design of the loading mandrel on the experimental stress-strain data has been investigated in detail. To validate the methodology, miniature tensile specimens have been tested and the data has been compared to those of ring specimens.
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Zhang, Xiaofei, Yuting Liu, Bo Zhang, and Peipei Wei. "Experimental Study on Basic Mechanical Properties of SiO2 Modified Basalt Fiber Concrete." In Advances in Frontier Research on Engineering Structures. IOS Press, 2023. http://dx.doi.org/10.3233/atde230225.
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The tensile performance of concrete is not good. In order to explore the improvement effect of highly active Nano-SiO2 (NS) particles on the basic mechanical properties of Basalt fiber (BF) concrete. BF particles with high cost performance and NS particles with high activity were added into concrete in the way of single and mixed, respectively. The compression and splitting tensile test were performed, and the microstructure and failure mechanism of concrete were analyzed by electron microscopic experiment. The results show that the increase rate of compressive strength and splitting tensile strength of BF doped concrete is up to 4.31% and 13.41% respectively. The increase rate of compressive strength and splitting tensile strength of single-doped NS concrete is up to 8.9% and 5.43% respectively. The maximum increase rate of compressive strength and splitting tensile strength of BF and NS concrete is 16.29% and 23.91%, respectively. According to the results of microscopic microscopy, the mixing of BF and NS can greatly improve the mechanical properties of the foundation, because the integrity of concrete is enhanced after the incorporation of NS, which makes the bond between BF and cement mortar close, and thus improves the compressive and splitting tensile strength of basalt fiber concrete.
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El Bahaoui, Jalal, Mohamed Chairi, Guido Di Bella, Chiara Borsellino, and Federica Favaloro. "Effect of Fiber Orientation and Matrix Type on Machining Behavior and Structural Integrity of Glass and Basalt Fiber-Reinforced Polymer Composites." In Machining Polymer Matrix Composites, 39–64. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-9927-6.ch002.
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The marine industry is adopting composite materials with a polymer matrix for shipbuilding due to new technologies and high-performance expectations. However, selecting the right material is challenging, especially considering the machining behavior required for manufacturing cylindrical composite structures. This study focused on evaluating the turning operation and mechanical properties of composites made of glass and basalt fibers with a polymer matrix specifically for maritime construction. The composites consisted of two fabric types, six layers, and two fiber orientation lay-ups, using vinyl ester resin and polyester as the matrix. Test specimens were machined and analyzed, revealing that the hardness and mechanical properties had an impact on the machining process. Glass fiber reinforced polymer (GFRP) samples were successfully machined, resulting in well-formed and undamaged FRP bars. In contrast, basalt fiber reinforced polymer (BFRP) specimens faced difficulties during machining, with matrix splitting, interfacial delamination, fiber ripping.
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Wu, Chen, Chengqing Liu, Yanning Lou, and Tao Sheng. "Experimental Study on Mechanical Properties of Laminated Bamboo Board Rubber Isolation Bearing for Rural Buildings." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220920.
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A new type of isolation bearing with advantages of low carbon, low cost and light weight is designed for rural buildings by using reinforced and recombined bamboo board instead of steel plates. First, the compression shear static load test of the reinforced composite bamboo board is carried out. The results show that: When the pure pressure is 20 MPa, the through cracks begin to appear along the grain direction of the bamboo board; When the pressure bearing capacity is 5 MPa and the shear bearing capacity is 3 MPa, there are a few cracks in the transverse direction, but they still have integrity. Then, taking a double story rural building in Wenchuan County, Sichuan Province as an example, a new type of bearing is used to design the base isolation scheme, and the quasi-static test was carried out. The results show that: (1) During the small earthquake, the bamboo board is not cracked, and the support remains intact. The shear stiffness in the longitudinal direction is about 30% higher than that in the transverse direction, and the equivalent damping ratio in the longitudinal and transverse directions is about 5%; (2) During the medium earthquake, a few cracks appear in the bamboo board, but the support is still intact. The stiffness along the grain direction is reduced by about 20%, but the damping ratio remains unchanged, and the mechanical properties along the grain direction are not affected; (3) During a large earthquake, there are many cracks in the bamboo board, but the bearing can still effectively bear the load. The stiffness in the longitudinal direction is further reduced by about 13%, and the transverse direction is basically unchanged. The damping ratio in the longitudinal and transverse directions is increased to 8–10% respectively. Therefore, the new isolation bearing is feasible.
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Cheshire, William P. "Cardiovagal Reflexes." In Clinical Neurophysiology, 661–76. Oxford University Press, 2009. http://dx.doi.org/10.1093/med/9780195385113.003.0039.
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Noninvasive cardiovascular tests are reliable and reproducible and are widely used to evaluate autonomic function in human subjects. The heart rate response to deep breathing is probably the most reliable test for assessing the integrity of the vagal afferent and efferent pathways to the heart. This is because respiratory sinus arrhythmia is a relatively pure test of cardiovagal function, whereas many other conditions, such as plasma volume, antecedent rest, and cardiac and peripheral sympathetic functions, factor into the Valsalva response. Heart rate variability to deep breathing is usually tested at a breathing frequency of 5 or 6 respirations per minute and decreases linearly with age. The Valsalva maneuver consists of a forced expiratory effort against resistance and produces mechanical (phases I and III) and reflex (phases II and IV) changes in arterial pressure and heart rate. When performed under continuous arterial pressure monitoring with a noninvasive technique, the Valsalva maneuver provides valuable information about the integrity of the cardiac parasympathetic, cardiac sympathetic, and sympathetic vasomotor outputs. The responses to the Valsalva maneuver are affected by the position of the subject and the magnitude and duration of the expiratory effort. In general, it is performed at an expiratory pressure of 40 mm Hg sustained for 15 seconds. The Valsalva ratio, the relationship between the maximal heart rate response during phase II (straining) and phase IV (after release of straining), has been considered a test of cardiac parasympathetic function. However, without simultaneous recording of arterial pressure, this may be misleading. An exaggerated decrease in arterial pressure during phase II suggests sympathetic vasomotor failure, whereas an absence of overshoot during phase IV indicates the inability to increase cardiac output and cardiac adrenergic failure.
Conference papers on the topic "Mechanical Integrity Test (MIT)"
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Yoo, Youngik, Kyounghong Kim, Kyongbo Eom, Seongki Lee, and Jongsung Yoo. "Finite Element Analysis for Fuel Assembly Structural Behavior." In 2018 26th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icone26-81621.
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Spent nuclear fuel (SNF) integrity evaluation related to its handling and transportation for mid-/long-term dry storage is a regulatory requirement. Especially, a drop event is the most fatal failure mode among regulatory conditions. For SNF drop accidents, it is required that the mechanical integrity of the SNF be evaluated using test results or analytic methodologies. The SNF mechanical test, however, takes much time and cost, and there are safety issues related to the release of radioactive materials. Thus, finite element analysis is used as an alternative to the experimental test method to solve this problem. In this study, a three dimensional (3D) finite element model was developed using ABAQUS software to simulate the structural behaviors of a fresh fuel assembly (FA) prior to applying SNF properties because of a lack of SNF test results. Static and dynamic mechanical behaviors were simulated with this model and compared with the fresh FA test results. The analysis results are in good agreement with the test results. Therefore, the analysis model consistent with the test results will be applied to the evaluation of the FA drop integrity reflecting the specific SNF characteristics.
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Araujo, Paulo, José Carlos Teixeira, Dionisio Silveira, Elisabete Silva, Delfim Soares, Raul Fangueiro, and Maria Cândida Vilarinho. "Development of Fiber Structures for High Performance Heat Resistant Curtains." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-24016.
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Abstract The protection of human life and goods assumes a growing concern in all forms of activities. The fire and smoke curtains have as main role to act as a physical barrier to prevent the fire from spreading between spaces as well as to staunch the smoke and heat transfer to adjacent areas. They can also be easily operated (opening and closing) causing a minimal interference with the flow of materials and humans within confines spaces, such as warehouses and industries, while providing adequate protection. Thus, there are a set of characteristics that these products must exhibit high fire protection, thermal resistance and gas impermeability. The classification of the heat resistance, described in the European Standard BS EN 1634-1: Fire resistance and smoke control tests for door, shutter and, openable window assemblies and elements of building hardware — fire resistance tests for doors, shutters and openable windows, is the procedure that allows determining the response of a product in contributing by its decomposition to a fire to which it is exposed, being according to three criteria: (i) integrity, (ii) insulation and (iii) radiation. Usually curtains are based on fiber-based structures which can be coated to enhance their protective capabilities. In addition, the fibrous structure can be tailored to optimize its behaviour using 2D and 3D complex architectures, with single or multiple materials. The performance assessment of the curtains regarding the aforementioned parameters is performed resorting to several experimental procedures that are detailed in the specific standards. The present paper reports the development of novel fibrous structures used for heat protection curtains. They are based on the various combinations of hybrid structures combining 2 or 3 different yarn materials. The tests are carried out in a purpose built oven that induces a steep temperature rate (approximately 600 °C in 5 min) on one side of the sample followed by a slower rate up to 950 °C in 60 min. The sample is placed under stress during the test in order to mimic that caused by its own weight. Thermocouples monitor the temperature on both sides of the sample and its integrity is assessed by both the occurrence of fabric rupture and smoke release due to ignition. Both the fabric integrity and the temperature on the back side of the sample are an indicator of its performance which follows the European Standard BS EN 13501-2: Fire classification of construction products and building elements. Classification using data from fire resistance tests, excluding ventilation services. From the results one can conclude that hybrid structures, including either basalt and glass fibers, are the most suitable.
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McKeighan, Peter C., David Y. Jeong, and Joseph W. Cardinal. "Mechanical Properties of Tank Car Steels Retired From the Fleet." In 2009 Joint Rail Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/jrc2009-63060.
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As a consequence of recent accidents involving the release of hazardous materials (hazmat), the structural integrity and crashworthiness of railroad tank cars have come under scrutiny. Particular attention has been given to the older portion of the fleet that was built prior to steel normalization requirements instituted in 1989. This paper describes a laboratory testing program to examine the mechanical properties of steel samples obtained from tank cars that were retired from the fleet. The test program consisted of two parts: (1) material characterization comprised of chemical, tensile and Charpy V-notch (CVN) impact energy and (2) high-rate fracture toughness testing. In total, steel samples from 34 tank cars were received and tested. These 34 tank cars yielded 61 different pre-1989 TC128-B conditions (40 shell and 21 head samples), three tank cars yielded seven different post-1989 TC128-B conditions (four shell and three head samples), and six tank cars yielded other material (A212, A515, and A285 steel) conditions (six shell and five head samples). The vast majority of the TC128-B samples extracted from retired tank cars met current TC128-B material specifications. Elemental composition requirements were satisfied in 97 percent of the population whereas the required tensile properties were satisfied in 82 percent of the population. Interpretation of the high-rate fracture toughness tests required dividing the pre-1989 fleet into quartiles that depended on year of manufacture or age, and testing three tank cars per quartile. Considering the high-rate fracture toughness results at 0°F for the pre-1989 fleet, 100 percent of the oldest two quartiles, 58 percent of the second youngest quartile, and 83 percent of the youngest quartile exhibited adequate or better fracture toughness (defined as toughness greater than 50 ksi√in). High-rate fracture toughness at –50°F was adequate for 83 percent of two quartiles (the youngest and second oldest), but the other two quartiles exhibited lower toughness with only 33 (2nd youngest) to 50 percent (oldest) exhibiting adequate properties.
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Janczewski, Jacek, Ulf Nilsson, Torsten Strand, and Christian Troger. "Heat Load on the Walls of an Annular DLE Combustor Calculation and Comparison With Experiments." In ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/98-gt-454.
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The knowledge of the hot gas side heat load is a necessary prerequisite for the design of the advanced cooling scheme of a dry low-NOx combustor and the mechanical integrity (MIT) calculations of the combustor walls. The magnitude and the spatial distribution of the heat fluxes has to be known in the very early phase of the design, where there is no hardware available. The evaluation of a combustor wall design has to be based on known process data, thermodynamic and combustion parameters and has to rely on computational methods and experience. A stepwise computational approach is presented to reach this target utilising • 1D flow and Nusselt-Number correlations • 2-D boundary layer code • computational fluid dynamics (CFD) For the validation of the method atmospheric and pressurised single burner combustor tests were performed. The relative merits and pitfalls of the different methods are discussed in detail. Recommendations for their utilisation within the design process and for their further development are given.
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Haggag, Fahmy M., and Larry D. Phillips. "Integrating Automated Ball Indentation With ASME B31G Code to Assess Integrity of Corroded Pipelines." In 2004 International Pipeline Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ipc2004-0357.
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In order to provide deterministic structural integrity assessment for safe and efficient operation of corroded pipelines, the following information is required: (a) the actual key mechanical properties (yield and ultimate strength, and fracture toughness) of the pipeline materials, (b) the present thickness and diameter of the pipeline, and (c) the profile of the maximum depth of corrosion pits over the pipeline axial length, and the size of sharp cracks. Both items (b) & (c) can be determined by conventional techniques. A patented in-situ Stress-Strain Microprobe (SSM) system was used to provide item (a), the required key mechanical properties (tensile and fracture toughness), in a nondestructive and localized fashion without any interruption of the pipeline transmission using its novel Automated Ball Indentation (ABI) test technique. The SSM system was used on a short segment of a 356-mm (14-inch) diameter Kerosene pipeline. Although there was no documentation of the pipeline steel grade, the minimum ABI-measured yield strength at four locations was 277 MPa (40.2 ksi) and the minimum ultimate tensile strength was 378 MPa (54.8 ksi) indicating that the steel met the requirements of Grade “A”. Both the Rstreng software and the ASME B31G code were used to calculate the maximum safe operating pressure for the corroded pipeline. The calculations showed that a profile with a few corrosion pits [3–6 mm (0.075–0.236 inch) maximum depth spaced over 483 mm (19 inches) length] reduced the maximum safe pressure significantly from 4.24 MPa (615 psi) to 0.74 MPa (107 psi). The operator of the pipeline limited the maximum operating pressure to 0.69 MPa (100 psi). Furthermore, it was recommended that the ABI measurements be performed on at least 10% of the 7-km Kerosene pipeline and on all patches and welds in order to provide the minimum yield strength values required for determining the remaining strength of the pipeline. This work proves that the integration of the ABI measurements with the corrosion pitting profile allows calculation of the maximum safe operating pressure in order to make the appropriate decision of replacement or repair of certain pipeline sections.
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Yu, Hailing, Yim H. Tang, Jeffrey E. Gordon, and David Y. Jeong. "Modeling the Effect of Fluid-Structure Interaction on the Impact Dynamics of Pressurized Tank Cars." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11926.
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This paper presents a computational framework that analyzes the effect of fluid-structure interaction (FSI) on the impact dynamics of pressurized commodity tank cars using the nonlinear dynamic finite element code ABAQUS/Explicit. There exist three distinct phases for a tank car loaded with a liquefied substance: pressurized gas, pressurized liquid and the solid structure. When a tank car comes under dynamic impact with an external object, contact is often concentrated in a small zone with sizes comparable to that of the impacting object. While the majority of the tank car structure undergoes elastic-plastic deformations, materials in the impact zone can experience large plastic deformations and be stretched to a state of failure, resulting in the loss of structural integrity. Moreover, the structural deformation changes the volume that the fluids (gas and liquid) occupy and consequently the fluid pressure, which in turn affects the structural response including the potential initiation and evolution of fracture in the tank car structure. For an event in which the impact severity is low and the tank car maintains its structural integrity, shell elements following elastic-plastic constitutive relations can be employed for the entire tank car domain. For events in which the impact severity is higher and the tank car is expected to be punctured, an equivalent plastic strain based fracture initiation criterion expressed as a function of stress triaxiality is adopted for the material in the tank car’s impact zone. The fracture initiation is implemented for ductile, shear and mixed fracture modes and followed by further material deterioration governed by a strain softening law. Multi-layered solid elements are employed in the impact zone to capture this progressive fracture behavior. The liquid phase is modeled with a linear Us–Up Hugoniot form of the Mie-Gru¨neisen equation of state, and the gas phase is modeled with the ideal gas equation of state. Small to moderate amounts of fluid sloshing are assumed for an impacted tank car in this study. As such, the FSI problem can be solved with the Lagrangian formulation of ABAQUS, and appropriate contact algorithms are employed to model the multi-phase interactions. The force, displacement and impact energy results from the finite element analysis show good correlations with the available shell (side) impact test data. The puncture energy of a tank car in a shell impact scenario is further analyzed. It is demonstrated that the FSI effect needs to be adequately addressed in an analysis to avoid overestimating the puncture resistance of a tank car in an impact event.
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Saiyed, S., S. A. Kudtarkar, R. Murcko, and K. Srihari. "Assessment of 20 Micrometer Diameter Wires for Wire Bond Interconnect Technology." In ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ipack2007-33691.
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In the domain of wire bonding technology, the size and pitch of bond pads and ball bonds are shrinking to accommodate the demand for higher I/Os and increased functionality per chip area. This trend serves as a catalyst for bonding wire manufacturers to continuously develop lower diameter bonding wires. One mil (25 μm) diameter bonding wire, used widely in this interconnection technique, is now being replaced by 0.8 mil (20 μm) diameter bonding wire. In keeping with the need for higher operating speeds and higher temperatures for today’s ICs, the reliability of ball bonds formed by small diameter wires is of concern and requires investigation. This study explores the effects of 0.8 mil (20 μm) diameter bonding wire on the wire bond ball joint reliability and compares these effects with 1.0 mil (25 μm) diameter bonding wire. The reliability of the ball bonds was assessed using mechanical tests (wire pull and ball shear) for units subjected to stress tests such as the unbiased highly accelerated stress test and high temperature storage tests. The results of this investigation reveal that both the wire diameters are able to sustain their integrity after moisture testing. But, the bond strength degrades after high temperature tests due to the Kirkendall voiding mechanism occurring between gold wire and the aluminum bond pad.
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Allameh, Seyed M., Hadi Allameh, Roger Miller, Avery Lenihan, and Dhruv Kota. "On the 3D Printing of Reinforced Concrete." In ASME 2023 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/imece2023-112719.
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Abstract Automation of construction industry has been long due given the rapid advances in construction technology. This is particularly true about the fabrication of structures such as houses, office buildings, bridges and other life-sustaining structures. From the contour crafting experiments of two decades ago to the recent building of modern homes in US and abroad, the technology has seen growth in quality of the concrete and the processing methodologies utilized. However, these structures are not currently made with reinforced concrete that sustains dynamic shear forces imposed on multiple-story structures, tensile forces in bridges and concrete beams and roofs. To develop the construction automation one step further and pave the way to do 3D printing of reinforced concrete, several issues have to be addressed. The first one is the feasibility of incorporation of rebar into concrete by co-printing of rebar and its ceramic matrix. While this has been demonstrated to be possible, the strength of the 3D printed rebar and its interfacial strength has to be validated. A number of tests of both monotonic and cyclic tensile types have been conducted, showing that the mechanical properties of printed rebar are comparable to those of conventional rebar at microscale. These include yield strength and fatigue limit. The results of these studies clearly show the microscale ultimate tensile strength of the 3D printed rebar using mild steel MIG wire stands at about 630MPa which is nearly identical to that of mild steel conventional rebar. Micro-fatigue test results show that both mild steel rebar and its 3D welded counterpart have similar fatigue limits nearing 430 MPa. The results of microtensile and microfatigue tests, both show higher UTS and fatigue limits compared to macroscale properties of conventional rebar. The results of prior work cited above suggest the reliability of 3D printing of reinforced concrete. However, it is necessary to examine other factors that make reinforced concrete such a valuable life-sustaining composite. One such factor is the interfacial integrity of the interface between the printed rebar with its concrete matrix which is the focus of this study. To examine the interfacial strength of 3D printed rebar and its role in strengthening reinforced concrete, several tests are designed and carried out. These include fabrication of a beam of reinforced concrete with conventional construction technology to be used as the control specimen. This method consists of placing conventional rebar in a mold and pouring concrete on the beam. A similar beam is then made by fabricating rebar by 3D printing using a MIG welder torch. The bottom rebars of the second concrete beam are then chosen from the 3D printed rebars, completing the task by pouring concrete in the mold over the rebars. After curing for 7 days, both concrete reinforced beams are tested in 4-point bend configuration. The results of the tests have shown lesser tensile strength for the 3D printed rebar compared to the conventional counterpart. Furthermore, flexural strength of the concrete beam with 3D printed rebar at as the bottom cords was found to be lesser than the control beam that contained only conventional rebar. However, even the lower tensile and flexural load capacities of 3D printed rebar and the resulting reinforced concrete are still high enough to be of interest to construction industry.
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Sammakia, Bahgat, and Sanjeev Sathe. "Thermal Issues That Arise due to Manufacturing Processes: Evaluation and Measurement Techniques." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0925.
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Abstract This paper describes the methodology used to design and evaluate the strength and reliability of the thermal interface between the chip and heat sink (coverplate) in a TBGA first level package. TBGA is a new technology that is part of the new generation of organic ball grid array chip carriers that are quickly gaining popularity for packaging various microprocessors and memory in portables, desktops, mid-range and high-end mainframes. The package consists of a Kapton or Upilex dielectric layer with one signal plane and one ground plane on either side, as shown in Figure 1. The chip is attached to the package with the signal side ‘down’, that is, facing the card. This leaves the backside of the chip available for coverplate (flat copper heat sink) attach. This direct access to the chip allows for a very effective thermal path from the chip directly to the heat sink, resulting in outstanding thermal performance. It is therefore essential to ensure that the interface between the chip and the heat sink remains intact through the end of the assembly processes for the package, including second-level attach to the board and rework. The interface must also remain intact through the life of the product. It is also necessary to ensure that the interface survives all of the necessary qualification stresses including accelerated thermal cycling, thermal age and deep thermal cycling, to name a few. First the results of a numerical analysis are presented showing the impact of surface de-lamination upon the thermal performance of the package. The model used is a full three-dimensional conjugate model accounting for conduction and radiation effects in the package, as well as the natural convection flow in the surrounding air. The results confirm that delamination of the interface degrades the thermal performance of the package. The model and test results also indicate that, due to the robustness of the package, voids or incomplete coverage of the chip with the thermal adhesive results in a relatively small degradation of the thermal performance of the package, provided total de-lamination of the chip or coverplate does not occur. The methodology used in evaluating different design options, such as adhesive material and heat sink surface treatment, is then described in detail. The primary method used for evaluating interfacial strength is a modified fracture toughness test (MFTT). This is the best measure of resistance to crack propagation. In conjunction with the MFTT, a sonographic technique was used to evaluate the integrity of the interface as a function of stress. Finally, a laser moiré tool is employed to evaluate the strains in the package due to thermal stress. The moiré results are shown for an intact package as well as for a completely de-laminated package, showing the differences in the mechanical response of the package due to delamination.
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Zheng, Gang, Feng Shen, Yi Peng, Fang Wu, Jundong Wang, and Lipei Chen. "A III+ Generation Pressurizer Stress Analysis and Evaluation." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63415.
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A large scale pressurizer is used in III+ generation Nuclear Power Plant (NPP) which requires a high safety standard. The finite element method was adopted in this study to analyse and evaluate a III+ NPP pressurizer. A 2D integral symmetric model was created for the Upper Head, Lower Head and Shell which comprise the pressurizer. The typical Safety Relief Nozzle was selected to be representative of the nozzles in this analysis. A 3D local model was created for the Safety Relief Nozzle. The pressurizer was loaded under design condition to test its structure integrity and was further evaluated by American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME B&PVC) [1]. Furthermore, a model optimization method was proposed for the 3D nozzle model under ANSYS Workbench. The results showed that the pressurizer stress analysis fully met the ASME B&PVC criteria under design condition. The model optimization method was demonstrated to be valid and could be used for nozzle analysis and evaluation.
Reports on the topic "Mechanical Integrity Test (MIT)"
1
Voegeli, Sam. PR-317-10701-R01 Temperature Logging as a Mechanical Integrity Test (MIT) for Gas-Filled Caverns. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2012. http://dx.doi.org/10.55274/r0010850.
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This report documents the work performed to evaluate the possibility that temperature log anomalies (�cold spots� or departures from temperature linearity with depth) can be indicators of well leaks. The natural gas cavern storage industry does not have a methodology for accurate gas-filled cavern well Mechanical Integrity Tests (MITs). Analyses of some temperature log anomalies in North American gas cavern well completions revealed that temperature log anomalies can be indicators of well leaks. The challenges in applying this technology to quantify gas-filled cavern MITs are threefold: (1) Does a temperature anomaly (�cold spot�) always indicate a leak? (2) Can a leak magnitude be correlated to a temperature log anomaly magnitude? and (3) What protocol should be used for executing such an MIT? This report is not intended to completely address all three issues noted above. However, the research presented here is one of many steps needed to evaluate the possibility of temperature logging as an MIT. Research activities discussed in this report involve computational fluid dynamics (CFD) modeling of both a well and cavern. Specifically, the response from a representative cold spot introduced in the cement sheath of a well and the response from an actual leak are addressed.
2
Li, Jun. Aboveground Injection System Mechanical Integrity Test Results Report. Office of Scientific and Technical Information (OSTI), January 2018. http://dx.doi.org/10.2172/2004876.
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Buchholz. L52308 Temperature Logging as a Cavern Mechanical Integrity Test. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), October 2010. http://dx.doi.org/10.55274/r0010397.
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This work documents case histories, develops an analytical solutions to predict a temperature decreases that occurs when gas leaks out of a well, and performs a computational fluid dynamics analyses of a generic gas well.
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Roberts, Barry L. Sensitivity Analysis of Salt Storage Cavern Mechanical Integrity Test Parameters. Office of Scientific and Technical Information (OSTI), April 2020. http://dx.doi.org/10.2172/1615452.
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Wei, Fulu, Ce Wang, Xiangxi Tian, Shuo Li, and Jie Shan. Investigation of Durability and Performance of High Friction Surface Treatment. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317281.
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The Indiana Department of Transportation (INDOT) completed a total of 25 high friction surface treatment (HFST) projects across the state in 2018. This research study attempted to investigate the durability and performance of HFST in terms of its HFST-pavement system integrity and surface friction performance. Laboratory tests were conducted to determine the physical and mechanical properties of epoxy-bauxite mortar. Field inspections were carried out to identify site conditions and common early HFST distresses. Cyclic loading test and finite element method (FEM) analysis were performed to evaluate the bonding strength between HFST and existing pavement, in particular chip seal with different pretreatments such as vacuum sweeping, shotblasting, and scarification milling. Both surface friction and texture tests were undertaken periodically (generally once every 6 months) to evaluate the surface friction performance of HFST. Crash records over a 5-year period, i.e., 3 years before installation and 2 years after installation, were examined to determine the safety performance of HFST, crash modification factor (CMF) in particular. It was found that HFST epoxy-bauxite mortar has a coefficient of thermal expansion (CTE) significantly higher than those of hot mix asphalt (HMA) mixtures and Portland cement concrete (PCC), and good cracking resistance. The most common early HFST distresses in Indiana are reflective cracking, surface wrinkling, aggregate loss, and delamination. Vacuum sweeping is the optimal method for pretreating existing pavements, chip seal in particular. Chip seal in good condition is structurally capable of providing a sound base for HFST. On two-lane highway curves, HFST is capable of reducing the total vehicle crash by 30%, injury crash by 50%, and wet weather crash by 44%, and providing a CMF of 0.584 in Indiana. Great variability may arise in the results of friction tests on horizontal curves by the use of locked wheel skid tester (LWST) due both to the nature of vehicle dynamics and to the operation of test vehicle. Texture testing, however, is capable of providing continuous texture measurements that can be used to calculate a texture height parameter, i.e., mean profile depth (MPD), not only for evaluating friction performance but also implementing quality control (QC) and quality assurance (QA) plans for HFST.
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Mohr, H. O. PR-209-9217-R01 Mechanical Connections for J-lay. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 1994. http://dx.doi.org/10.55274/r0012126.
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This report discusses the results of a testing program designed to simulate the operational conditions imposed on a J-lay installed, 13%" subsea pipeline assembled with mechanical connections. The program objective was to gain an understanding of the long-term sealing integrity of various mechanical connections. The connections were subjected to combinations of cyclic internal pressure, cyclic temperature, axial compression, and reverse torsion. The testing results show that the mechanically interlocked Reflange C-Con II connection and two premium threaded connections, the Hunting Fox and Sumitomo Varn Ace, when assembled utilizing suitable bonding agents, successfully resisted the imposed loads of this testing program. In addition, the selection of a proper bonding agent or adhesive to prevent reverse torque back out proved to be important as several of these agents were unreliable in preventing back out failures. The testing conditions applied to the mechanical connections in this test program are believed to be conservative, exceeding the maximum that in-service, J-lay installed pipelines are likely to experience. Therefore, this test program may be used to select a pipeline connection for this duty.
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Author, Unknown. PR-203-027-R01 Evaluation of Screen Testing Program for J-Lay Connections. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 1992. http://dx.doi.org/10.55274/r0012125.
Full textAbstract:
This report discusses the results of a testing program designed to simulate the operational conditions imposed on a J-lay installed, 13%" subsea pipeline assembled with mechanical connections. The program objective was to gain an understanding of the long-term sealing integrity of various mechanical connections. The connections were subjected to combinations of cyclic internal pressure, cyclic temperature, axial compression, and reverse torsion. The testing results show that the mechanically interlocked Reflange C-Con II connection and two premium threaded connections, the Hunting Fox and Sumitomo Varn Ace, when assembled utilizing suitable bonding agents, successfully resisted the imposed loads of this testing program. In addition, the selection of a proper bonding agent or adhesive to prevent reverse torque back out proved to be important as several of these agents were unreliable in preventing back out failures. The testing conditions applied to the mechanical connections in this test program are believed to be conservative, exceeding the maximum that in-service, J-lay installed pipelines are likely to experience. Therefore, this test program may be used to select a pipeline connection for this duty.
8
Haines and Rosenfeld. L52125 Physical Performance and Inspection Objectives to Inspect Currently Non Piggable Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2004. http://dx.doi.org/10.55274/r0011137.
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A significant portion of the pipeline infrastructure cannot be assessed for integrity using in-line inspection. There may also be reasons why some segments cannot be readily assessed by hydrostatic testing or by direct assessment. New standards and regulations for integrity management provide for using other technology that can be demonstrated to be as effective in assessing for the presence of integrity threats as the standard techniques. The first part of the report discusses a survey of PRCI member pipeline operating companies investigating the reasons why their systems are not piggable. The results are intended to be an aid to determining the direction of future PRCI research and development efforts. The results revealed that 62% of the pipe surveyed is presently piggable, and those members answering the survey plan to make another 21% of the system piggable. The survey further indicated that members plan to use direct assessment as the primary choice for inspecting nonpiggable segments. Consequently, the survey suggests that the primary goal of the Committee in addressing nonpiggable lines should be to validate direct assessment, followed by developing new above ground direct assessment and metal loss detection tools. The second part of the report discusses an analysis to establish suitable detection criteria for alternative assessment methods. Criteria for metal loss due to corrosion were established for 2 NPS to 24 NPS pipe of Grades B, X42, and X52 in all standard class locations so as to assure the same margin of safety afforded by the minimum hydrostatic test required per class. Criteria were also proposed for stress-corrosion cracking, selective corrosion in ERW seams, and mechanical damage.
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Jarram, Paul, Phil Keogh, and Dave Tweddle. PR-478-143723-R01 Evaluation of Large Stand Off Magnetometry Techniques. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), February 2015. http://dx.doi.org/10.55274/r0010841.
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Monitoring the integrity of buried ageing ferromagnetic pipelines is a significant problem for infrastructure operators. Typically inspection relies on pig surveys, lDCVG, CIPS and contact NDT methods that often require pipes to be uncovered and often at great expense. This report contains the results of trials carried out on a controlled test bed using a novel remote sensing technique known as Stress Concentration Tomography (SCT) which claims to be capable of detecting corrosion, metal defects and the effects of ground movement by mapping variations in the earth's magnetic field around pipelines. The physical law upon which SCT has been engineered is Magnetostriction which is the process by which internal domains inside the structure of ferromagnetic materials, such as carbon steel alloys, create magnetic fields when subjected to mechanical stress. This report contains the results of controlled trials of the technology which potentially offers pipeline operators, particularly those of non-piggable pipelines, the benefit of considerable inspection cost savings since it is a non-invasive technique and no modification to the line or its operational parameters is required.
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Tandon, Samarth, and Ravi Krishnamurthy. PR-328-223812-R01 Tools and Methods to Assess Pipe Material Properties from Inside the Pipeline. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), December 2023. http://dx.doi.org/10.55274/r0000047.
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With the energy transition to alternative fuels like ethanol and hydrogen, the use of existing pipeline networks to transport these fuels would be the most economical. Pipeline tensile and fracture toughness material property characterization would be essential for fitness-for-service for alternate fuel transportation. Pipeline and Hazardous Materials Safety Administration (PHMSA) Gas Transmission 49 Code of Federal Regulations (CFR) Part 192 states that if there is missing or inadequate material documentation, an operator must "implement a program to test pipe samples to establish material properties". The Maximum Operating Pressure (MOP) and Maximum Allowable Operating Pressure (MAOP) should be established using the record evidence and integrity management, requiring material properties like grade, yield, and tensile strength. Incomplete or partial records are inadequate for establishing MOP or MAOP. The current research explores tools and technologies that can reliably assess the material properties of components of a steel pipeline from the inside of the pipeline without requiring extensive excavation. The material properties in consideration are yield strength, toughness, ductility, hardness, and fracture toughness. Additionally, chemical composition and distribution and morphology of phases and grain structure characterization would be beneficial. The long seam weld type characterization assists with pipeline integrity management. Characterization of mechanical properties, including grade, fracture behavior, and metallurgical properties, is invaluable in confirming MOP and MAOP. More importantly, material characterization allows operators to determine these pipelines' suitability for alternative fuel transportation. The research explores mainly two different ILI technologies, MFL and Eddy Current, that can be used for material property characterization. Five different ILI technology providers were contacted, and their ILI technology reviewed for material property determination. One robotic inspection technology for hardness measurement was also explored. The study reviews the technologies, provides performance measures and recommendations for future research work.