Letteratura scientifica selezionata sul tema "Displacement damages"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Displacement damages".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Articoli di riviste sul tema "Displacement damages"
1
Zhu, Jia Wei, Dan Ting Zhou e Qiu Wei Yang. "Damage Localization for a Continuous Beam by the Displacement Variation". Applied Mechanics and Materials 744-746 (marzo 2015): 366–69. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.366.
Testo completoAbstract (sommario):
Using the static displacement data, this paper presented a damage localization method for a continuous beam. This method is based on the estimation of changes in the static displacements of the structure. The most significant advantage of the method is that it does not require development of an analytical model of the structure being tested. All predictions are made directly from the measurments taken on the structure. The efficiency of the proposed method is demonstrated using simulated data of a three-span continuous beam. The results showed that the region in which the displacement variation is maximum is the damaged region for the continuous beam. Regardless of damages being small or large, the proposed method can identify locations of structural damages accurately only using the displacement changes under the applied static load. The proposed procedure is economical for computation and simple to implement. The presented scheme may be useful for damage localization of the continuous beam.
2
Tiongson, Samuel Francisco, e Ryan Ramirez. "Mapping of ground surface deformations and its associated damage using SAR interferometry: a case study of the 2020 Masbate earthquake". E3S Web of Conferences 347 (2022): 03014. http://dx.doi.org/10.1051/e3sconf/202234703014.
Testo completoAbstract (sommario):
The 2020 Masbate earthquake in the Philippines, with a moment magnitude 6.6, occurred on August 18, 2020. The earthquake dealt considerable damage to the surrounding areas. This study uses Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) to investigate earthquake-induced damages. Conventional repeat-pass InSAR is used to quantify the ground surface displacement along the radar line-of-sight (LOS). The InSAR technique shows ground surface displacements greater than 15 cm. This study also implements a two-step coherence difference analysis coupled with a statistical temporal coherence threshold to map and delineate the locations of damages associated with the earthquake. The InSAR-derived damage locations are consistent with the actual locations of damages, as reported from a field survey. This study confirms the effectiveness and accuracy of Sentinel-1 InSAR techniques for earthquakeinduced damage mapping applications.
3
Xiao, Feng, Weiwei Zhu, Xiangwei Meng e Gang S. Chen. "Parameter Identification of Frame Structures by considering Shear Deformation". International Journal of Distributed Sensor Networks 2023 (16 agosto 2023): 1–12. http://dx.doi.org/10.1155/2023/6631716.
Testo completoAbstract (sommario):
This paper presents a method to identify the damages in frame structures with slender beams. This method adjusts the parameters of the structure to match the analytical and the measured displacements. The effect of transverse shear deformation on the nodal analytical displacement is analyzed, and the parameter identification of frame structures with slender beams is performed. The results demonstrate that parameter-identification accuracy can be considerably improved by considering the transverse shear deformation in the frame structure with slender beams. The proposed method can accurately identify the damages in frame structures with slender beams using displacement measurements.
4
Li, Cui Hong, Qiu Wei Yang e Xue Shen. "Damage Detection for Cantilever Beam Structures Using Two-Stage Method". Applied Mechanics and Materials 351-352 (agosto 2013): 1084–87. http://dx.doi.org/10.4028/www.scientific.net/amm.351-352.1084.
Testo completoAbstract (sommario):
This paper presents a two-stage method for damage identification in cantilever beam structures using the incomplete measured static and dynamic paramenters. The first stage locates damages preliminary by using the static displacement changes, which is obtained by the static test of structure. It has been shown that the point from which the static displacement difference starts increasing linearly is the location of damage. After the suspected damaged elements are determined in the first stage, the first order sensitivity of the structural natural frequency is used to identify damages more precise in the second stage. The significant advantage of the proposed method is that it is economical in computation and is simple to implement. A cantilever beam structure is analyzed as a numerical example to verify the present method. Results show that the proposed method performs well even if the measurement errors inevitably make the damage assessment more difficult. It has been shown that the presented two-stage methodology may be a promising tool to be used by research groups working on experimental damage detection.
5
Bhargav Sai, Cherukuri, e D. Mallikarjuna Reddy. "Dynamic Analysis of Faulty Rotors through Signal Processing". Applied Mechanics and Materials 852 (settembre 2016): 602–6. http://dx.doi.org/10.4028/www.scientific.net/amm.852.602.
Testo completoAbstract (sommario):
In this study, an effective method based on wavelet transform, for identification of damage on rotating shafts is proposed. The nodal displacement data of damaged rotor is processed to obtain wavelet coefficients to detect, localise and quantify damage severity. Because the wavelet coefficients are calculated with various scaled indices, local disturbances in the mode shape data can be found out in the finer scales that are positioned at local disturbances. In the present work the displacement data are extracted from the MATLAB model at a particular speed. Damage is represented as reduction in diameter of the shaft. The difference vectors between damaged and undamaged shafts are used as input vectors for wavelet analysis. The measure of damage severity is estimated using a parameter formulated from the distribution of wavelet coefficients with respect to the scales. Diagnosis results for different damage cases such as single and multiple damages are presented.
6
Zhao, Bingchao, Pan Chen, Jingbin Wang, Jingui Zhang e Di Zhai. "A Comprehensive Evaluation and Analysis of Ground Surface Damage Due to Mining under Villages Based on GIS". Applied Sciences 13, n. 18 (8 settembre 2023): 10136. http://dx.doi.org/10.3390/app131810136.
Testo completoAbstract (sommario):
This paper aims to evaluate the severities and causes of ground surface building and cropland damages after coal mining in a better way, and to clarify the correlation between the damage assessment indexes that influence mining. Against the backdrop of multi-seam mining in certain coal mines in China, the estimated results of each displacement and deformation were analyzed using GIS technology. The damage range determined for each deformation index is divided according to the displacement and deformation combined with the virtue of damage judgment threshold. The damage ranges on the ground surface based on the comprehensive value of each displacement and deformation index were obtained through superimposing those ranges delineated by each displacement and deformation index, and the law on influence from displacement indexes upon various levels of damage was analyzed in a quantitative manner accordingly. The results showed that coal mining destroyed 14 buildings and a cropland area of 11.96 hm2; among them, building damage was only associated with displacement indexes E (horizontal deformation) and T (inclined deformation). Seven buildings were solely destroyed by T alone; five buildings were solely damaged by E; two buildings were damaged jointly by E and T; and, moreover, with the aggravation in building damage level, the proportion of building damage due to E decreased while the proportion of building damage under the same level due to T increased. Regarding cropland destruction, the damage due to T accounted for 33.48% while the damage jointly caused by W (Subsidence), E and T accounted for 30.45%. Moreover, the proportion of damaged cropland area due to inclined deformation T was positively correlated with cropland damage level. These findings can provide a reference for rational judgment regarding civilian building and cropland destruction on the ground surface after coal mining.
7
Auersch, L. "Characteristics of train passages over slab tracks from measurements and different track–soil models: Damage detection and ground vibration reduction". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 234, n. 2 (6 marzo 2019): 142–60. http://dx.doi.org/10.1177/0954409719835036.
Testo completoAbstract (sommario):
The characteristics of train passages over intact or damaged slab tracks on different soils have been calculated by the finite-element boundary-element method or the wavenumber-domain method. The influence of track and soil parameters on the distribution of track displacements and soil forces has been analysed. The measured and calculated displacement time histories of train passages could be used to identify track damages such as loose sleepers or a loose track plate. The time histories and spectra of soil forces can explain the measured ground vibration reduction in the slab tracks. The calculated displacement and force distributions of slab tracks on continuous soils do not fulfil the Winkler hypothesis, and Winkler models should not be used for track analysis.
8
Guo, De Ping, e Masanori Hamada. "Lessons Learnt from Seismic Damage Induced by the 2008 Wenchuan Earthquake". Applied Mechanics and Materials 226-228 (novembre 2012): 889–96. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.889.
Testo completoAbstract (sommario):
The 2008 Wenchuan earthquake with a surface wave magnitude of 8.0 induced numerous infrastructure damages. The typical seismic damages of 61 bridges, 18 tunnels and slope reinforcements are presented. The results show longitudinal or transverse displacement was the most widespread bridge seismic damage and resulted in girder dropping, shear key failure, joint expansion and support damage. Pillar was sheared off or crushed failure due to strong motions and lack of sufficient hoop steels. Tunnel damage was mainly observed at portal, which was mostly caused by slope failure. Strong ground shaking caused multi-direction cracks in the lining, shear failure of lining resulted from serious surrounding rock relative displacement. Investigation of slope reinforcements suggests anchor cable and frame beam had good anti-seismic property. Furthermore, some suggestions about resistant countermeasures to future earthquake are proposed.
9
Ruan, Zhigang, e Zuguang Ying. "Effectiveness analysis of structural anomaly diagnosis based on ANN model". Vibroengineering PROCEDIA 42 (16 maggio 2022): 21–26. http://dx.doi.org/10.21595/vp.2022.22446.
Testo completoAbstract (sommario):
Assessing and localizing damages are an important problem in structural engineering. Artificial neural networks (ANN) have an excellent pattern recognition capability. In this paper, a structural anomaly diagnosis method based on ANN model using displacement response signals is proposed to assess and localize damages, and applied to a five-story frame structure under random base excitation. The random displacement responses are used as the input to ANN for detecting structural damages, which differ from conventional methods such as using modal parameters extracted from responses. The ANN model is set up by training and then validation using random displacement responses. Damages in a structure are denoted by stiffness degradation. Detection results are mainly affected by incomplete measurement due to intensive noise, finite sampling time length and measured degree of freedom (DOF). Numerical results show the effects of the incomplete measurement on the accuracy of predicting damages based on the proposed method.
10
Çöğürcü, Mustafa Tolga, e Mehmet Uzun. "Effect of configuration of shear walls at story plan to seismic behavior of high-rise reinforced concrete buildings". Challenge Journal of Structural Mechanics 6, n. 1 (25 marzo 2020): 31. http://dx.doi.org/10.20528/cjsmec.2020.01.004.
Testo completoAbstract (sommario):
In developing countries, the need for shelter, working area, shopping and entertainment centers is increasing due to the increasing population effect. In order to meet this need, it is necessary to turn to high-rise buildings. Significant damages have been observed as a result of insufficient horizontal displacement stiffness of high-rise buildings in major earthquakes in previous years. It is known that as the height of the structure increases, the displacement demand of the structure also increases. Since it is accepted that the structure will make inelastic deformation in the design of the structure, these displacements increase to very high levels as the number of stories increases. For this reason, damages can be much higher than expected. In order to limit the level of damage that may occur in high-rise buildings, the horizontal displacement of buildings is limited in many regulations in our age. This limitation is possible by increasing the rigidity of the structures against horizontal displacement. In recent years, the use of shear wall has increased due to the horizontal displacement limitation in the regulations. The use of shear walls in buildings limits the horizontal displacement. However, the choice of where the shear walls will be placed on the plan is very important. Failure to place the shear walls correctly may result in additional loads in the structure. It can also lead to torsional irregularity. In this study, a 10-storey reinforced concrete building model was created. Shear wall at the rate of 1% of the plan area of the building was used in the building. The shear walls are arranged in different geometric shapes and different layouts. The earthquake analysis of 5 different models were performed. Equivalent Earthquake Load, Mode Superposition and Time History Analysis methods were used for earthquake analysis. The results were compared and a proposal was made for the geometry and configuration of the shear wall.
Tesi sul tema "Displacement damages"
1
Jouni, Ali. "Space radiation effects on CMOS single photon avalanche diodes (SPADs)". Electronic Thesis or Diss., Toulouse, ISAE, 2024. http://www.theses.fr/2024ESAE0012.
Testo completoAbstract (sommario):
Le sujet de cette thèse traite des effets des radiations spatiales sur des détecteurs CMOS à avalanches, et particulièrement sur les dispositifs SPADs (pour Single Photon Avalanche Diode en anglais, ou photodiode à avalanche à photon unique). Ces photodiodes présentent un gain interne presque infini et sont donc sensibles à des très faibles conditions de lumières. Ainsi, avec en plus une excellente résolution temporelle, ces capteurs peuvent être très intéressant pour des applications spatiales nécessitant des mesures de temps de vols, comme la topographie d’objets célestes ou les Rendez-vous spatiaux. Cependant, l’espace est un environnement hostile du fait des radiations provenant du Soleil, des particules piégées dans la magnétosphère terrestre ainsi qu’au-delà du système solaire. De ce fait, dans le cadre de ces travaux de thèse, un modèle est mis en place pour prédire la dégradation du courant d’obscurité des SPADs, le Dark Count Rate (DCR), après des irradiations aux protons. Expérimentalement, deux technologies de matrices de SPADs sont irradiées avec des protons, des rayons X et des rayons γ. De ce fait, les effets ionisants et non-ionisants sont investigués pour ces capteurs à avalanches, et des différences en comparaison avec les pixelsdes capteurs d’images standard sont soulignées. Ensuite, les caractéristiques des défauts induits par la création d’états d’interface entre les oxides et le silicium et les dommages de déplacement atomique dans le substrat sont examinées, avec notamment la présence de comportement RTS (Random Telegraph Signal). Enfin, l’identification de la nature de ces défauts est réalisée par l’intermédiaire de recuits isochrones après l’expositions des matrices de SPADs aux trois différentes radiations mentionnées au-dessusThe subject of this thesis deals with the effects of space radiation on CMOS avalanche detectors, particularly on Single Photon Avalanche Diodes (SPADs). These photodiodes exhibit nearly infinite internal gain and are therefore sensitive to very low light conditions. Thus, with excellent temporal resolution, these sensors can be very interesting for space applications requiring time-of-flight measurements, such as the topography of celestial objects or space Rendezvous. However, space is a hostile environment due to radiation from the Sun, particles trapped in the Earth’s magnetosphere, and beyond the solar system. Consequently, within the framework of this thesis work, a model is established to predict thedegradation of the dark current of SPADs, the Dark Count Rate (DCR), after proton irradiations. Experimentally, two SPAD array technologies are irradiated with protons, X-rays, and γ rays. Hence, ionizing and non-ionizing effects are investigated for these avalanche sensors, and differences compared to pixels of standard image sensors are highlighted. Subsequently, the characteristics of defects induced by the creation of interface traps between oxides and silicon and atomic displacement damage in the substrate are examined, including the presence of Random Telegraph Signal (RTS) behaviors. Finally, the nature of these defects is identified through isochronal annealing after irradiations of the SPAD arrays using the three different radiation types mentioned above
2
Kim, Young-Seog. "Damage structures and fault evolution around strike-slip faults". Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340659.
Testo completo
3
Tappin, David Keith. "The characterisation of displacement cascades in austenitic Fe-Cr-Ni alloys". Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317254.
Testo completo
4
Sutton, Akil K. "Displacement Damage and Ionization Effects in Advanced Silicon-Germanium Heterojunction Bipolar Transistors". Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7217.
Testo completoAbstract (sommario):
A summary of total dose effects observe in advanced Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) is presented in this work. The principal driving froces behin the increased use of SiGe BiCMOS technology in space based electronics systems are outlined in the motivation Section of Chapter I. This is followed by a discussion of the strained layer Si/SiGe material structure and relevant fabrication techniques used in the development of the first generation of this technology. A comprehensive description of the device performance is presented.
Chapter II presents an overview of radiation physics as it applies to microelectronic devices. Several sources of radiation are discussed including the environments encountered by satellites in different orbital paths around the earth. The particle types, interaction mechanisms and damage nomenclature are described.
Proton irradiation experiments to analyze worst case displacement and ionization damage are examined in chapter III. A description of the test conditions is first presented, followed by the experimental results on the observed dc and ac transistor performance metrics with incident radiation. The impact of the collector doping level on the degradation is discussed.
In a similar fashion, gamma irradiation experiments to focus on ionization only effects are presented in chapter IV. The experimental design and dc results are first presented, followed by a comparison of degradation under proton irradiation. Additional proton dose rate experiments conducted to further investigate observed differences between proton and gamma results are presented.
5
Khorsandi, Behrooz. "Modeling of displacement damage in silicon carbide detectors resulting from neutron irradiation". Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1173103438.
Testo completo
6
CAMBIAGGI, LUDOVICA. "Damage assessment of churches exposed to slope displacements in sliding areas". Doctoral thesis, Università degli studi di Genova, 2020. http://hdl.handle.net/11567/1029444.
Testo completoAbstract (sommario):
Protecting cultural heritage from water-soil interaction related threats is a current issue and the prediction of the effects of slope displacements on buildings is very challenging. The achievement of this goal is not straightforward since it usually requires high costs due to the great amount of data to be collected for setting up reliable forecasting models. Among these threats, slow moving landslides are considered in this research, because also small slope movements can seriously affect existing structures and cause damages. In this regard, the aim is to develop a simple but effective procedure to correlate the potential damage caused to soil displacements to the slope safety conditions, represented by an “intensity parameter” such as the slope safety factor. Churches located in, or close to, landslide areas, have been chosen as exposed structures: this choice makes the theme more challenging for the structural and geometric complexities of these particular historic buildings. Furthermore, while modelling and estimating the effects induced by deep excavations or tunnelling on existing buildings are known and widely treated geotechnical problems, the assessment of the damage caused by landslide movement has not been fully developed and only limited material exists in the literature.
The procedure developed and proposed in the Thesis takes into account:
i) identification and characterization of the exposed elements;
ii) assessment of displacements and associated strain level components caused by slope movement via numerical analyses;
iii) iii) proposal and assessment of an intensity parameter representative of deformations and stability conditions;
iv) iv) assessment of damage severity levels and develop of fragility curves,
v) v) validation of the proposed approach.
7
McKenna, Alice J. "Ab initio and molecular dynamic models of displacement damage in crystalline and turbostratic graphite". Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/809906/.
Testo completoAbstract (sommario):
One of the functions of graphite is as a moderator in several nuclear reactor designs, including the Advanced Gas-cooled Reactor (AGR). In the reactor graphite is used to thermalise the neutrons produced in the fission reaction thus allowing a self-sustained reaction to occur. The graphite blocks, acting as the moderator, are constantly irradiated and consequently suffer damage. This thesis examines the types of damage caused using molecular dynamic (MD) simulations and ab intio calculations. Neutron damage starts with a primary knock-on atom (PKA), which is travelling so fast that it creates damage through electronic and thermal excitation (this is addressed with thermal spike simulations). When the PKA has lost energy the subsequent cascade is based on ballistic atomic displacement. These two types of simulations were performed on single crystal graphite and other carbon structures such as diamond and amorphous carbon as a comparison. The thermal spike in single crystal graphite produced results which varied from no defects to a small number of permanent defects in the structure. It is only at the high energy range that more damage is seen but these energies are less likely to occur in the nuclear reactor. The thermal spike does not create damage but it is possible that it can heal damaged sections of the graphite, which can be demonstrated with the motion of the defects when a thermal spike is applied. The cascade simulations create more damage than the thermal spike even though less energy is applied to the system. A new damage function is found with a threshold region that varies with the square root of energy in excess of the energy threshold. This is further broken down in to contributions from primary and subsequent knock-on atoms. The threshold displacement energy (TDE) is found to be Ed=25eV at 300K. In both these types of simulation graphite acts very differently to the other carbon structures. There are two types of polycrystalline graphite structures which simulations have been performed on. The difference between the two is at the grain boundaries with one having dangling bonds and the other one being bonded. The cascade showed the grain boundaries acting as a trap for the knock-on atoms which produces more damage compared with the single crystal. Finally the effects of turbostratic disorder on damage is considered. Density functional theory (DFT) was used to look at interstitials in (002) twist boundaries and how they act compared to AB stacked graphite. The results of these calculations show that the spiro interstitial is more stable in these grain boundaries, so at temperatures where the interstitial can migrate along the c direction they will segregate to (002) twist boundaries.
8
CONSOLANDI, CRISTINA. "Displacement damage induced by cosmic rays in silicon devices using geant4 toolkit for space applications". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2010. http://hdl.handle.net/10281/7870.
Testo completoAbstract (sommario):
In the space environment the dominant radiation at energies above 50 MeV/nucleon is constituted by the Galactic Cosmic Rays (GCRs) which are capable to inflict permanent damage to silicon devices.
In particular the displacement damage was analyzed and the
Non-Ionizing Energy Loss (NIEL) was calculated both at high and low energies in order to estimate the displacement damage for the entire energy range of the space radiation environment. Of particular relevance was the development of an improved implementation of the Geant4 single scattering model. This modification gives the possibility to calculate the Coulomb scattering contribution to the NIEL for heavy nuclei at high energies. Moreover the GCR fluxes of the ISO model 15390 was introduced in Geant4 as a particle generator in order to reproduce the solar modulation effect on GCRs. For instance, using the ISO model of GCRs fluxes and the NIEL for all the nuclei, we estimated the expected NIEL-Dose absorbed by a silicon sample during one year mission.
In addition Hall effect measurements were performed in our laboratory on silicon samples of different resistivities which are usually used as substrates for the fabrication of devices employed in space missions
9
Gerstel, Markus. "Radiation damage in protein crystallography : susceptibility study". Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:be55baee-19b7-4a34-8694-fb9c3606a19c.
Testo completoAbstract (sommario):
Protein structure models obtained from X-ray crystallography are subject to radiation damage. The resulting specific alterations to protein structures can be mistaken for biological features, or may obscure actual protein mechanisms, leading to misidentification or obscuration of biological insight. The radiation chemistry behind this site-specific damage is not well understood. Radiation damage processes progress in proportion to the dose absorbed by the crystal in the diffraction experiment. Doses can be estimated using existing software, but these assume idealised experimental conditions. To simulate complex diffraction experiments, including treatment of imperfect X-ray beam profiles and inhomogeneous dose distributions, a new program, RADDOSE-3D, was developed. RADDOSE-3D can be integrated into beamline software to provide convenient, more accurate, comparative, and publishable dose figures, also facilitating informed data collection decisions. There is currently no method to automatically detect specific radiation damage in protein structure models in the absence of an 'undamaged' reference model. Radiation damage research therefore generally relies on detailed observation of a few model proteins. A new metric, BDamage, is designed and used to identify and quantify specific radiation damage in the first large-scale statistical survey of 2,704 published protein models, which are examined for the effects of local environments on site-specific radiation damage susceptibility. A significant positive correlation between susceptibility and solvent accessibility is identified. Current understanding of radiation damage progression is mostly based on a few consecutive structure model 'snapshots' at coarse dose intervals. The low sampling rate considerably limits the ability to identify varying site susceptibility and its causes. Real space electron density data are obtained for crystals of different mutants of a RhoGDI protein with very high sequence identity, to determine sensitising and stabilising factors for radiation induced structural changes. Utilising a newly developed data collection and analysis protocol, these changes could be tracked with unprecedented time resolution.
10
Rauch, Alan F. "EPOLLS: An Empirical Method for Prediciting Surface Displacements Due to Liquefaction-Induced Lateral Spreading in Earthquakes". Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30346.
Testo completoAbstract (sommario):
In historical, large-magnitude earthquakes, lateral spreading has been a very damaging type of ground failure. When a subsurface soil deposit liquefies, intact blocks of surficial soil can move downslope, or toward a vertical free face, even when the ground surface is nearly level. A lateral spread is defined as the mostly horizontal movement of gently sloping ground (less than 5% surface slope) due to elevated pore pressures or liquefaction in undelying, saturated soils. Here, lateral spreading is defined specifically to exclude liquefaction failures of steeper embankments and retaining walls, which can also produce lateral surface deformations. Lateral spreads commonly occur at waterfront sites underlain by saturated, recent sediments and are particularly threatening to buried utilities and transportation networks. While the occurrence of soil liquefaction and lateral spreading can be predicted at a given site, methods are needed to estimate the magnitude of the resulting deformations.
In this research effort, an empirical model was developed for predicting horizontal and vertical surface displacements due to liquefaction-induced lateral spreading. The resulting model is called "EPOLLS" for Empirical Prediction Of Liquefaction-induced Lateral Spreading. Multiple linear regression analyses were used to develop model equations from a compiled database of historical lateral spreads. The complete EPOLLS model is comprised of four components: (1) Regional-EPOLLS for predicting horizontal displacements based on the seismic source and local severity of shaking, (2) Site-EPOLLS for improved predictions with the addition of data on the site topography, (3) Geotechnical-EPOLLS using additional data from soil borings at the site, and (4) Vertical-EPOLLS for predicting vertical displacements. The EPOLLS model is useful in phased liquefaction risk studies: starting with regional risk assessments and minimal site information, more precise predictions of displacements can be made with the addition of detailed site-specific data. In each component of the EPOLLS model, equations are given for predicting the average and standard deviation of displacements. Maximum displacements can be estimated using probabilities and the gamma distribution for horizontal displacements or the normal distribution for vertical displacements.Ph. D.
Libri sul tema "Displacement damages"
1
Displacement Damage Effects in Solar Cells: Mining Damage from the Microelectronics and Photonics Test Bed Space Experiment. Independently Published, 2020.
Cerca il testo completo
2
Suhail, Peer Ghulam Nabi. Pieces of Earth. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199477616.001.0001.
Testo completoAbstract (sommario):
Resource exploitation in the form of land-grabbing has become a major debate worldwide. Based on extensive field research conducted at the India-Pakistan border, using Kishanganga Hydroelectric Project as a case study, this book on corporate land-grabbing in Kashmir explains how capital is at play in a conflict zone. The author explains how different actors—village elites, government officers, politicians, civil society coalitions, peasants, and the states of India and Pakistan—mobilize support to legitimize their respective claims. It captures how the tensions between developmentalism, environmentalism, and national interest on one hand, and universal rights, national sovereignty, subnational identity, and resistance on the other—facilitate and challenge these corporate resource-grabs simultaneously. The author argues that the patterns and scale of land- and resource-grabbing has led to depeasantization, dispossession, displacement, loss of livelihoods, forced commoditization of the local peasantry, and damages to the local ecology at large. The book thus combines the literature in violence and development and dispossession studies by addressing the socio-political conflict in land- and resource-grabbing in conflict zones.
3
Moonesinghe, Ramini, e Sue Mallett. Acute pain in patients with renal or hepatic impairment. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199234721.003.0015.
Testo completoAbstract (sommario):
The metabolism and excretion of many analgesic drugs will be altered in the presence of renal or hepatic impairment. Some analgesic drugs can cause renal or hepatic damage. Protein binding of drugs may be altered by hepatic reduction in production or uraemic displacement from binding sites. In renal disease, paracetamol is the simple analgesic of choice. Morphine can be used with care in mild to moderate renal disease, but fentanyl or oxycodone may be better alternatives. Non-steroidal anti-inflammatory drugs should be avoided in renal disease. In hepatic disease with significant impairment, doses of morphine must be reduced and the dosage interval lengthened. Fentanyl should be avoided in severe hepatic disease.
4
Blaustein, George. Pictures from an Institution. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190209209.003.0004.
Testo completoAbstract (sommario):
The founding Americanist institution in postwar Europe took place in a baroque, bomb-damaged castle and had only the tenuous approval of the US military government in Austria. Leopoldskron Castle had been owned by the theater impresario Max Reinhardt before the Nazis expropriated it. The Salzburg Seminar in American Civilization, a transnational collaboration of student organizations and Christian relief agencies, repurposed the castle in 1947 to bring American thought and art to occupied Europe. Scholars, novelists, and poets carried the American word abroad and, in turn, were shaped by their encounters in the ruins. This chapter is the story of that institution’s early years, perched between the imaginary geography of Mitteleuropa and the political geography of the Cold War. The Seminar preceded the Marshall Plan, and its previously unexplored archives yield dramas of denazification, displacement, and the bifurcation of Europe.
5
Lawry-White, Merryl. Victims of Environmental Harm During Conflict. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198784630.003.0016.
Testo completoAbstract (sommario):
This chapter considers the interaction of some of the applicable norms related to liability and reparation for environmental damage in a post-conflict setting, including human rights and humanitarian law norms (including precedents) and their interaction with each other, with a focus on the potential consequences for victims. Using displacement as a specific case study, the discussion regarding potential consequences is supported by the learning that may be drawn from precedent reparations schemes, including those implemented in a ‘transitional justice’ framework as part of an attempt to afford ‘justice’ for breaches of human rights and humanitarian law (whether related to the environment or otherwise). The chapter considers some of the potential challenges of this interaction, particularly for justice initiatives, and particularly reparations schemes, experienced in the aftermath of conflict, such as constructing a coherent post-conflict narrative, restitution (or ‘truth’), awarding reparation (including ‘restitution’), and reconciliation as part of ‘peacebuilding’.
6
Thornton, Fanny. Climate Change and People on the Move. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198824817.001.0001.
Testo completoAbstract (sommario):
The book applies a justice framework to analysis of the actual and potential role of international law with respect to people on the move in the context of anthropogenic climate change. That people are affected by the impacts of climate change is no longer doubted, including with implications for the movement of people (migration, displacement, relocation, etc.). The book tackles unique questions concerning international responsibility for people movement arising from the inequities inherent to climate change. Corrective and distributive justice provide the analytical backbone. They are explored in a substantial theoretical chapter and then applied to subsequent contextual analysis. Corrective justice supports analysis as to whether people movement in the climate change context could be conceived or framed as harm, loss, or damage which is compensable under international law, either through fault-centred regimes or no-fault regimes (i.e., insurance). Distributive justice supports analysis as to whether such movement could be conceived or framed as a disproportionate burden, either for those faced with movement or those faced with sheltering people on the move, from which duties of redistribution may stem. The book contributes to the growing scholarship and analysis concerning international law or governance and people movement in response to climate change by investigating the bounds of the law where the phenomenon is viewed as one of (in)justice.
7
O' Dochartaigh, Killian. Uppland. University of Edinburgh, 2024. http://dx.doi.org/10.2218/ed.9781836450290.
Testo completoAbstract (sommario):
Uppland is a 30-minute research film tracing the complex relationship between landscape, displacement and the global extractive industries within, and beyond, sub-Saharan Africa. The film documents a new-town called Yekepa, designed and built by and for a mining company prospecting for iron-ore in the late 1950s, that exploited and transformed the indigenous landscapes of Yeke’pa. The film represents an original collaboration between an architect and a filmmaker. This research took them to the remote highlands of Liberia, once a thriving mining community, now a concrete ruin in the West African bush. Exploring the town, the researchers discovered promises of prosperity, abandonment and forgotten injustices. They revealed insights about western architecture, the remnants of colonialism, and the spiritual costs of mining. The main outputs from this work are a number of international screenings at major film festivals, architectural biennales, as well as contributions to an international conference in Sweden. Educational rights to the film were acquired for the distributing to international research institutions and universities across Europe and North-America. ‘It is a galling portrait of the harvesting of African resources and the damage done to both land and people... Uppland avoids most of the pitfalls of the narrated, exploitation documentary genre, its disembodied voice- over never becoming too authoritative, outraged, or self-indulgent – a rare achievement in this ever-expanding field.’ Danny Hoffman, Africa’s a Country, May 2019.
Capitoli di libri sul tema "Displacement damages"
1
Song, Zhiyu, Yafei Zhai e Guangkun Liu. "Analysis of Dynamic Response Characteristics of Towering Intake Towers Under the Action of Main-Aftershock Sequences". In Lecture Notes in Civil Engineering, 247–57. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-9184-2_22.
Testo completoAbstract (sommario):
AbstractAfter a strong earthquake occurs, it can cause a certain degree of damage to the structure, and the strong aftershock effect can cause secondary damage to the already damaged structure. In this study, taking a actual project of intake tower in the district of western strong earthquake as an example, the acoustic unit is used to simulate the dynamic effect of reservoir water on the tower body, and the overall nonlinear model of the water-intake tower-foundation is established. Combined with the site and seismic motion characteristics of the engineering area, the seismic motion sequence of the main-aftershocks was constructed based on the statistical relationship between the main shocks and strong aftershocks, as well as the NGA seismic motion attenuation model. The effects of main shock, aftershock, and main-aftershock on the structural damage evolution of intake towers in strong earthquake zones were investigated separately. The results show that after considering the aftershock effect, the damage and failure of the intake tower structure intensify, and its dissipation energy and residual displacement increase by about 20%~25%. Compared with the main shock, the aftershock alone causes less damage to the tower structure. However, for the intake tower structure that is damaged after the main shock, the aftershock can cause larger secondary residual deformation of the tower.
2
Ougouag, A. M., M. B. Danjaji, J. G. Williams e J. F. Stubbins. "Neutron Displacement Damage Functions For Iron". In Proceedings of the Seventh ASTM-Euratom Symposium on Reactor Dosimetry, 729–37. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2781-3_83.
Testo completo
3
Olivero, Massimo, Guido Perrone, Alberto Vallan e Silvio Abrate. "Plastic Optical Fiber Displacement Sensor for Cracks Monitoring". In Damage Assessment of Structures VII, 487–92. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-444-8.487.
Testo completo
4
Liu, Shihong, Qing Lei, Bo Jiang e Yao Zeng. "Evaluation of Treatment Effect of Highway Subgrade Reconstruction Damaged by Large Landslide". In Lecture Notes in Civil Engineering, 193–99. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-4355-1_18.
Testo completoAbstract (sommario):
AbstractHighway in mountainous area is easily threatened by landslide and other disasters, so it is necessary to comprehensively evaluate the prevention and control effect of the treatment when the subgrade is restored and rebuilt after landslide. In order to deeply study the landslide treatment effect of subgrade reconstruction, taking the landslide damage reconstruction of G326 highway in Guizhou Province as the object, the deformation and failure process of landslide induced by heavy rainfall is simulated, and the prevention effect of different treatment plans such as “cutting + anti-slide pile + anchor cable” is evaluated. The results show that with the increase of rainfall, the landslide deformation gradually expands from the vicinity of the front national G326 highway to the back edge; Under the combined treatment of “cutting + anti-slide pile + anchor cable”, the maximum displacement of the main sliding area of landslide is 3.1 mm, and the maximum displacement of the trailing edge is 1.7 mm, which makes the overall deformation in a controllable range. As a result, it has certain reference value for the reconstruction of highway subgrade engineering damaged by landslide.
5
Fang, Miaomiao, Yuqi Wang, Jiaxin Liu e Fan Sun. "Research on Support Damage of Highway Bridge Based on Midas". In Lecture Notes in Civil Engineering, 330–37. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1260-3_30.
Testo completoAbstract (sommario):
AbstractDuring the operation of highway bridges, the bearing stiffness will decrease with the service life, and the mechanical properties will also change. In order to study the influence of stiffness damage on bearing. In this paper, a continuous beam bridge is selected for finite element model analysis, and the effects of stiffness damage on bearing force and bearing offset under the conditions of concrete shrinkage and creep and 30 °C temperature difference are comprehensively considered. The results show that the bearing stiffness damage has little influence on the vertical displacement, horizontal displacement and bearing capacity of the bearing, but has a great influence on the vertical compression deformation and durability of the bearing.
6
Claeys, Cor, e Eddy Simoen. "Displacement Damage in Group IV Semiconductor Materials". In Radiation Effects in Advanced Semiconductor Materials and Devices, 53–108. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04974-7_3.
Testo completo
7
Jia, Yueqiao, e Jeffrey Chiang Choong Luin. "Finite Element Analysis of Reinforced Concrete Slab-Rectangular Column Connections Using ABAQUS". In Advances in Frontier Research on Engineering Structures, 33–44. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-8657-4_4.
Testo completoAbstract (sommario):
AbstractRectangular columns used in flat-slab structures run the risk of punching shear damage due to stress concentrations, especially when bending moments and vertical forces act together at the connections. Using the finite element analysis method, the existing experiments are numerically simulated using the 3D modeling software ABAQUS, and describe the cracking behavior of concrete using the concrete damaged plasticity model. The accuracy of the numerical simulation was calibrated by load–displacement curves and crack patterns using the experimental results. The study of the model was set up with different moment-to-shear ratios and outputs the trend of the average shear stress on the eccentric force side of the slab. The moment transfer coefficients are derived through the equation of ACI-318 and compared with the code values. A safe range of side length ratios is proposed to reduce the risk of punching shear damage from the use of rectangular columns. This provides a reference for practical design, but more experiments are needed to support the proposed recommendations.
8
Hamada, Masanori. "Liquefaction-Induced Ground Displacements: Damage and Countermeasures". In Springer Series in Geomechanics and Geoengineering, 153–227. Tokyo: Springer Japan, 2014. http://dx.doi.org/10.1007/978-4-431-54892-8_4.
Testo completo
9
Zhao, Fei, Shaoyu Zhao e Shuli Fan. "Effect of Autoclaved Aerated Concrete on Dynamic Response of Concrete Gravity Dam Under Earthquakes". In Lecture Notes in Civil Engineering, 409–26. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2532-2_35.
Testo completoAbstract (sommario):
AbstractAutoclaved Aerated Concrete (AAC) is commonly used in lower floors buildings in low seismicity areas due to its lightweight property and high energy absorption capacity. This paper proposes a novel application of AAC as an effective seismic countermeasure in the reduction of vibrational energy for concrete gravity dam. According the vibrating characteristics and failure modes of gravity dam under earthquake excitation, AAC was placed in the upper zone of a gravity dam to reduce the seismic inertia force and consequently to increase the seismic safety of the dam. Dynamic responses of two non-overflow sections of a gravity dam were analyzed through finite element analysis utilizing a damaged plasticity constitutive model. The anti-seismic effect of using AAC in gravity dams is researched by inputting different kind of ground motion records. The comparison of the natural vibration characteristics, dam crest displacement, and dynamic damage of the dam were investigated. The results show that, AAC effectively improves seismic resistance of concrete gravity dams, particularly eliminating cracks in the concrete along reduced damage zones, through inertial force reduction and energy dissipation. The results warrant further considerations for applying AAC to gravity dams.
10
Arai, Tatsuya, e Kenichi Sakaue. "Measurement of Crack Tip Displacement Field in Desiccating Paste". In Fracture, Fatigue, Failure, and Damage Evolution, Volume 5, 67–72. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06977-7_9.
Testo completoAtti di convegni sul tema "Displacement damages"
1
YAJIMA, YOSHIYUKI, MURTUZA PETLADWALA, TAKAHIRO KUMURA e CHUL-WOO KIM. "NATURAL FREQUENCY AND DISPLACEMENT RATIO BASED PROBABILISTIC DAMAGE IDENTIFICATION FOR BRIDGES USING FE MODEL UPDATE". In Structural Health Monitoring 2023. Destech Publications, Inc., 2023. http://dx.doi.org/10.12783/shm2023/37012.
Testo completoAbstract (sommario):
This paper proposes a natural frequency and displacement ratio-based probabilistic damage identification method for bridges using the finite element (FE) model update. When the damage location is known, it can be detected from an appropriate damagesensitive feature (DSF). However, damaged components are seldom known before inspections. This makes it difficult to find an appropriate DSF and damage identification is sometimes challenging. This paper aims to propose a method to solve this issue by integrating multiple DSFs, natural frequencies and displacement ratio, as a decisionlevel data fusion approach. They are complementary in terms of sensitivity to damage. In addition, probability density functions (PDFs) of structural parameters are estimated from PDFs of observed DSFs through the FE model update to consider errors and uncertainties in measurement data. An in-house model bridge experiment is carried out to investigate the feasibility. The results demonstrated that the two kinds of damages in a bearing and girder reproduced in the experiment were successfully identified without false positives even when these damages simultaneously occurred.
2
"Improving the Drive-by Bridge Inspection Performance by Vehicle Parameter Optimization". In Structural Health Monitoring. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901311-23.
Testo completoAbstract (sommario):
Abstract. Recently, there has been an increasing emphasis in the Indirect bridge health monitoring method employing passing vehicles, which is regarded as one of the most effective approaches in bridge damage screening. However, few researches have been conducted on the Drive-by bridge inspection method using vehicle displacement profile as damage indicator due to the challenges in displacement measurement and result accuracy. This paper proposes an optimization approach of designing the optimum vehicle parameters to improve the performance of vehicle displacement-based Drive-by bridge damage inspection. A generalized Vehicle-Bridge Interaction (VBI) system is built in MATLAB, where the bridge is modelled as a simply supported beam with 10 elements and the passing vehicle is represented as a simplified quarter car. Employing the Monte Carlo methods, the optimum parameters are determined by numerous simulations processed under diverse damage scenarios. Results show that by employing the optimal vehicle parameters, the bridge damages can be detected effectively and accurately for general damage scenarios based on the vehicle displacement profile. The proposed optimization method can contribute to the wide application of vehicle displacement-based Drive-by bridge damage inspection, providing merits in simplicity and visualization.
3
Yan, Renjun, Yao Qi, Bailu Luo, Jiajing Lei e Peng Li. "Computing Methods and Application Development of Longitudinal Strength of Damaged Ships". In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-21027.
Testo completoAbstract (sommario):
In this paper, it starts by providing a description of the scenarios of damages that can be found in the various accidental events. Based on a traditional standardized approach for calculating longitudinal strength of ships, an improved method for longitudinal strength of damaged ships, which can be applied to any traditional type of ships, is presented in next section. The variation of loads in damaged ships is related to the effects of the ingress of water with the consequences of changing the ship displacement, a non-symmetric floating body, and the load case of compartments before damage, etc. The computing methods used in this paper allow for research on corresponding applications. Using this computer program, a few case studies are carried out and the results are discussed.
4
Yang, Yang, e Xianglin Gu. "Collapse Simulation of Damaged Reinforced Concrete Frame Structures in Earthquakes". In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.1011.
Testo completoAbstract (sommario):
<p>A simulation system based on the discrete element method (DEM) was developed to simulate the collapse behavior of damaged reinforced concrete (RC) frame structures in earthquakes. A frame structure was discretized into beam-column-joint discrete system according to its failure mode. The elements were assumed to be cuboid, and a group of concrete springs and steel bar springs were set between two adjacent elements to represent their interactions. The failure of material was initiated by fracture of springs, and the impact actions among separated components were considered. Using the simulation system, the full-range collapse process of an RC frame, including debris stacking, was visually simulated. The efficiency of the system was verified by comparing the simulated collapse behavior with that observed in a collapse experiment. A new method, in which concrete springs and steel bar springs were cut off in advance to simulate the respective initial imperfection, was proposed to model earthquake-induced damage states of RC frame structures. Then displacement loadings were conducted to form the respective damage states. Finally, a parametric analysis was conducted to investigate the collapse processes of the RC frame with different scenarios of initial damage. The results indicated that the initial damages on columns were of greater influence on collapse patterns than the initial damages on beams, and the residual interstory drifts were nonnegligible in evaluating the structural collapse resistance.</p>
5
Nakashima, Teruhiro, e Tomoyo Taniguchi. "A Study of Applicability of Finite Displacement Analyses With Semi-Analytical Finite Elements for Analyzing Uplift Displacement of Flat-Bottom Cylindrical Shell Tanks Statically". In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97584.
Testo completoAbstract (sommario):
The rocking motion of tanks due to earthquakes causes the large uplift deformation of the tank bottom plate that has been considered to contribute to the various damages of the tanks. For analyzing the uplift displacement of the tank bottom plate statically and precisely, this paper develops a shell element, ring element and spring element partially attached to the ring element. These elements are defined as a semi-analytical finite element. Fourier series give its circumferential displacement function, while the polynomial gives its radial displacement function. In addition, the ring element can deal with effects of the large deformation, while the spring element enables to express the partial contact between the tank bottom plate and foundation. On the other hand, the loads considered are dead load, hydro-pressure and inertia force due to earthquakes acceleration as well as dynamic pressure of fluid induced by bulging and rocking motion of the tank. The numerical analyses model of the LNG Storage Tank was created using the semi-analytical finite elements shown here, and the uplift displacement of the tank bottom plate accompanying the tank rocking motion was calculated with the static analyses. For evaluating analytical accuracy of the proposed method, numerical results of the proposed method are compared with that of the explicit FE Analysis.
6
Noda, Michiyasu, Akira Maekawa, Michiaki Suzuki e Masanori Shintani. "Development of Evaluation Method of Vibrational Stress in Piping System Applying Multiple Laser Displacement Sensors". In ASME 2007 Pressure Vessels and Piping Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/pvp2007-26453.
Testo completoAbstract (sommario):
Many damages of the piping system in the nuclear power plants have occurred due to the vibration fatigue induced by the mechanical vibration of pumps and so on. One of the preventive measures for the problem of vibration is the evaluation of vibrational stress, which is the methods using the strain gauge and the accelerometer. However, these evaluation methods require highly specialized skills and many man-hours, and nuclear plants are awaiting the development of vibration-measuring techniques and evaluation techniques that are easy to perform and produce accurate results promptly. The purpose of this study is the development of the method and the device measuring the vibrational stress directory using the laser displacement sensor. The proposed method evaluates the vibrational stress as follows: Three laser displacement sensors measure the displacement of the piping induced by vibrating, and the strain of the piping is calculated from the difference among the sensor-measured displacements to determine vibrational stress. The measurement equipment isn’t direct contact with the piping evaluated, can be easily reduced in size, and can realize quick and accurate measurement. This paper describes the concept of the proposed evaluation method of vibrational stress in the piping system using three laser displacement sensors, along with its theory and measurement procedure. And then, refer to the proposal of the evaluation method of torsional vibration using six laser displacement sensors. This paper also compares the stress values calculated based on the cantilever vibration identified by this method and the stress values calculated based on material mechanics, and discusses the applicability of the method in actual plants.
7
GHODAKE, PRAVINKUMAR. "NONLINEAR BULK WAVE PROPAGATION IN A MATERIAL WITH RANDOMLY DISTRIBUTED SYMMETRIC AND ASYMMETRIC HYSTERETIC NONLINEARITY". In Structural Health Monitoring 2021. Destech Publications, Inc., 2022. http://dx.doi.org/10.12783/shm2021/36359.
Testo completoAbstract (sommario):
The nonlinear ultrasonic technique is an effective nondestructive testing technique for the detection of very small early-stage damages in solids that often remain insensitive to linear ultrasonic techniques. Interaction of a single frequency (f) ultrasonic wave with early-stage complex non-linear micro-defects such as dislocations, grains, micro-cracks, and micro-pores, etc., generates ultrasonic waves with higher harmonics (2f, 3f, 4f, 5f,…). In theoretical and computational studies, early-stage damages are modeled as homogeneous nonlinear material models like quadratic, cubic, and hysteretic nonlinearities. Interaction of single frequency wave with quadratic nonlinearity generates both odd and even harmonics but in the case of cubic and symmetric hysteretic nonlinearity, only odd harmonics generated due to material nonlinearity are observed. Symmetric hysteretic nonlinearity shows symmetric hysteretic force versus displacement hysteretic curves. In practice, the early-stage damages are highly localized and randomly distributed, and hysteretic. The objective of this investigation here is to study the interaction of a single frequency and two-frequency (one-way two-wave mixing) ultrasonic waves with the randomly distributed hysteretic nonlinear local damages. As the theoretical studies in hysteretic nonlinearities are challenging, here a numerical study of such a complex nature of wave propagation is considered. Symmetric and asymmetric hysteretic nonlinearities are considered independently. A one-dimensional spatial domain discretized as a long-chain of springmass elements with a random distribution of hysteretic spring elements. For symmetric hysteretic element, famously used Bouc-Wen model implemented and for asymmetric hysteretic element recently proposed Generalized Bouc-Wen model is implemented to capture asymmetric hysteretic force versus displacement nature of hysteretic curves. A single-frequency Gaussian pulse is sent from the left end of the spatial domain and the time responses are recorded at the one-fifth of total length and right end of the spatial domain. The same computational experiments repeated for ten different cases of randomly distributed symmetric and asymmetric hysteretic elements each and independently. In both the symmetric and asymmetric cases, harmonically scattered waves from randomly distributed local nonlinearities with sufficiently less amplitude than the input wave are observed. The frequency response of the recorded waves shows only odd harmonics in the case of randomly distributed symmetric hysteretic nonlinear damages, but in the case of asymmetric hysteretic nonlinear damages, both the odd and harmonics are observed. The evolving symmetric and asymmetric hysteretic curves are observed in the case of symmetric and asymmetric hysteretic nonlinear damages respectively. To understand the one-way two-wave mixing phenomenon in thesehysteretic nonlinearities, a Gaussian pulse with two input frequencies is sent from the left end of the spatial domain. Due to mixing in symmetric hysteretic damage, sum and difference frequencies corresponding to only odd harmonics of input frequency along with the odd original odd harmonics are seen. In asymmetric hysteretic damage cases, sum and difference frequencies corresponding to both the odd and even harmonics are observed along with the original odd and even harmonics. In mixing significant amount of input energy is supplied to the possible frequency combinations present near the first few odd and/or even harmonics.
8
Xu, Guangli, Liangxue Cai, Amos Ullmann e Neima Brauner. "Trapped Water Flushed by Flowing Oil in Upward-Inclined Oil Pipelines". In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90680.
Testo completoAbstract (sommario):
Pipe-line corrosion is of a major concern in the transportation of crude oil and natural gas. The corrosion is caused by the presence of water in contact with the walls. Following water-tests and/or shut-down, small amounts of water tend to accumulate at low sections along the pipe line. Flushing out of the water from the pipe by the oil flow is required to avoid damages in the pipeline. From a practical point of view, the minimal oil flow rate required for displacement and flush-out of the accumulated water by the oil flow has to be determined. Experimental study, mechanistic models and numerical simulations are used to investigate the characteristics of water displacement by oil flow in hilly terrain pipelines. Various mechanisms for the onset of water displacement from a lower (horizontal) section into an upward inclined section are considered and the associated minimal (critical) oil-flow rate for the water displacement is evaluated. For oil-flow rates exceeding the critical value, the possible patterns of water movement in the inclined pipe are examined.
9
Yamaguchi, Takeshi, Hiroki Aoi e Dai Wakabayashi. "Design of the Shintomei-Nakatsukawa Bridge - An extradosed bridge considering effect of large displacement due to a fault". In IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2021. http://dx.doi.org/10.2749/christchurch.2021.0285.
Testo completoAbstract (sommario):
<p>The Nakatsugawa Bridge is constructed over a valley with both ends linked to a tunnel. It was confirmed that there is a fault in the valley. This fault is likely to cause a relatively large vertical displacement, and fault fracture zones are distributed over a wide area. Considering these topographical and geological conditions, we planned a triple-span PC extradosed bridge which will prevent collapse in the event of a fault displacement, averting irreparable damages. Consequently, the side span is extremely short in comparison with the central span, because of space restrictions affecting arrangement of pylons and piers. This presented a challenge in that a significant imbalance between the spans might lead to a negative reaction at the girder end. This paper discusses a series of reviews made for bridge planning and design, and reports that the balance between the spans was improved successfully by using light weight butterfly webs exclusively for the central span.</p>
10
Lua, Jim, Ethan Fulghum, Xiaodong Cui, Jian Xiao, Supun Kariyawasam e Caleb Saathoff. "A Combined X-Ray CT and Mechanistic Characterization of Bearing Failure Mechanisms in Bolted Composite Components". In Vertical Flight Society 77th Annual Forum & Technology Display. The Vertical Flight Society, 2021. http://dx.doi.org/10.4050/f-0077-2021-16897.
Testo completoAbstract (sommario):
This paper presents the characterization of bearing failure mechanisms in composite joints with countersunk bolt by applying an X-ray Computed Tomography (XCT) technique and a developed bearing failure model to build the physical mechanisms into the framework of continuum damage mechanics (CDM) in our composite bolted and bonded analysis tool for Abaqus (CB2ATA). The high-fidelity XCT was explored for the detection and characterization of bearing failure in bolted composite components without removing the fastener, which could introduce significant scatter in XCT scan due to its high density, compared with lightweight carbon fiber reinforced polymer (CFRP) composite laminates. A static bearing model was also developed for the damaged material response in the bearing region based on a micromechanics analysis in the longitudinal and transverse directions. In this study, single shear bearing (SSB) tests was firstly executed with XCT scan, and then progressive failure analyses were performed to explore the effects of bolt failure on the interaction of the intra- and inter-ply damages. The predicted load-displacement response was compared with experimental measurement, and the simulated failure patterns were compared with the XCT images. A new design was proposed using the enhanced analysis tool to achieve a dominant bearing failure mechanism on the basis of the current SSB test.
Rapporti di organizzazioni sul tema "Displacement damages"
1
Auden, Elizabeth Catherine. Basic Mechanisms: Displacement Damage. Office of Scientific and Technical Information (OSTI), giugno 2019. http://dx.doi.org/10.2172/1524360.
Testo completo
2
Auden, Elizabeth Catherine. Test Standards: Displacement Damage. Office of Scientific and Technical Information (OSTI), giugno 2019. http://dx.doi.org/10.2172/1524361.
Testo completo
3
Mueller, G. P. The Inadequacies of Damage Energy as a Measure of Displacement Damage. Fort Belvoir, VA: Defense Technical Information Center, aprile 1989. http://dx.doi.org/10.21236/ada207376.
Testo completo
4
Griffin, Patrick. Relationship between Metrics Used to Represent Displacement Damage in Materials. Office of Scientific and Technical Information (OSTI), aprile 2014. http://dx.doi.org/10.2172/1617630.
Testo completo
5
Stoller, R. E., e L. R. Greenwood. Influence of subcascade formation on displacement damage at high PKA energies. Office of Scientific and Technical Information (OSTI), agosto 1997. http://dx.doi.org/10.2172/543219.
Testo completo
6
Esparza e Westine. L51482 Well Casing Response to Buried Explosive Detonations. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), luglio 1985. http://dx.doi.org/10.55274/r0010272.
Testo completoAbstract (sommario):
Occasionally, buried explosives are used within proximity of producing oil and gas wells which increases the stresses in the casing near the explosion which may result in failure of the well. A procedure was needed for predicting the maximum stresses in producing oil and gas wells, specifically the well casing, induced by nearby, buried, explosive detonations. An extensive experimental and analytical program were funded and performed over a six (6) year period 1975-1981. The program was divided into two (2) parts: In the first part, similitude theory, empirical analyses and test data were used to derive equations for estimating maximum ground displacement and particle velocity. The ground motions provided the forcing function imparted to a buried pipeline. In the second part, similitude theory, conservation of mass and momentum, and approximate energy methods were used to derive functional relationships for the maximum pipe strains and stresses. Experimental data from more than sixty (60) field tests ere used to develop equations for estimating maximum pipe stresses induced by point and parallel line explosive sources buried in homogeneous soil media. The pipe stress and ground motion data from these experiments were used to develop an equation for computing an effective standoff distance so that the point source soil equations could be used to approximate the casing response. The large amount of data used and the wide range of these data make the solutions applicable to most blasting situations near producing oil and gas wells. This report provides comprehensive and detailed information for pipeline as well as oil and gas operators to predict the effect of buried explosives and thus the safety of a well(s) while in-service through proper assessment of stresses and guidelines for the appropriate selection of explosive charges, techniques and methods. This will avoid unexpected damages, operational costs, provide guidance for \operator qualification\" for blasting near in-service wells and minimize liabilities to the operator.
7
Doyle, Barney Lee. Displacement damage caused by gamma-rays and neutrons on Au and Se. Office of Scientific and Technical Information (OSTI), novembre 2014. http://dx.doi.org/10.2172/1177090.
Testo completo
8
Stephens, Olson e Rosenfeld. L51620 Pipeline Monitoring--Limit State Criteria. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), settembre 1991. http://dx.doi.org/10.55274/r0010607.
Testo completoAbstract (sommario):
With the growing emphasis on extending the useful operation of existing pipelines and reducing the operating costs, the pipeline industry is sensitive to keeping pipelines in service and having a rational basis for doing so. When pipelines undergo fault displacement, mining subsidence, thaw settlement, or landslide induced soil loading, monitoring of pipeline strains and/or displacements must protect their integrity. Currently, there is little information available to indicate when remedial action is necessary for such a pipeline. This report focuses on assisting pipe-monitoring programs by providing data and criteria for monitoring intervention. The objective of the work reported herein was to compile data and define criteria for monitoring intervention for local buckling, denting, and tensile failure, based upon data and experience from the pipeline industry. It was established that three separate quantities might be defined for each loading condition; a limit state criterion, a damage state criterion, and an intervention criterion.
9
Doyle, Barney Lee, Daniel L. Buller, Harold Paul Hjalmarson, Robert M. Fleming, Edward Salvador Bielejec e Gyorgy Vizkelethy. Simulation of neutron displacement damage in bipolar junction transistors using high-energy heavy ion beams. Office of Scientific and Technical Information (OSTI), dicembre 2006. http://dx.doi.org/10.2172/913228.
Testo completo
10
Hattar, Khalid Mikhiel, e David Robinson. In-situ 3D characterization of He bubble and displacement damage in dense and nanoporous thin films. Office of Scientific and Technical Information (OSTI), ottobre 2015. http://dx.doi.org/10.2172/1226424.
Testo completo