Dissertationen: „Strains and stresses – Analysis“

1

Kennedy, Kevin Francis. „A method for metal deformation and stress analysis in rolling“. Connect to resource, 1986. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1261418472.

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2

Seki, Wataru. „Analysis of strain localization in hyperelastic materials, using assumed stress hybrid elements“. Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/19088.

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3

Caceres, Arsenio. „Local damage analysis of fiber reinforced polymer matrix composites“. Morgantown, W. Va. : [West Virginia University Libraries], 1998. http://etd.wvu.edu/templates/showETD.cfm?recnum=328.

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Thesis (Ph. D.)--West Virginia University, 1998.
Title from document title page. Document formatted into pages; contains x, 107 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 104-107).

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4

Nagaraja, Srinidhi. „Microstructural Stresses and Strains Associated with Trabecular Bone Microdamage“. Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14093.

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Bone is a composite material consisting of hydroxyapatite crystals deposited in an oriented manner on a collagen backbone. The arrangement of the mineral and organic phases provides bone tissue with the appropriate strength, stiffness, and fracture resistance properties required to protect vital internal organs and maintain the shape of the body. A remarkable feature of bone is the ability to alter its properties and geometry in response to changes in the mechanical environment. However, in cases of metabolic bone diseases or aging, bone can no longer successfully adapt to its environment, increasing its fragility. To elucidate the mechanisms of bone microdamage, this research project developed a specimen-specific approach that integrated 3D imaging, histological damage labeling, image registration, and image-based finite element analysis to correlate microdamage events with microstructural stresses and strains under compressive loading conditions. By applying this novel method to different ages of bovine and human bone, we have shown that the local mechanical environment at microdamage initiation is altered with age. We have also shown that formation of microdamage is time-dependent and may have implications in age-related microdamage progression with cyclic and/or sustained static loading. The work presented in this dissertation is significant because it improved our understanding of trabecular bone microdamage initiation and unlocked exciting future research directions that may contribute to the development of therapies for fragility diseases such as osteoporosis.

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5

Byun, Chansup. „Free vibration and nonlinear transient analysis of imperfect laminated structures“. Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-135342/.

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6

JEFFREY, ROBERT GRAHAM JR. „ROCKBOLT ANALYSIS FOR REINFORCEMENT AND DESIGN IN LAYERED ROCK (COMPOSITE)“. Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187982.

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The displacements and stresses in layered rock above underground openings can be calculated using a beam model for the rock layers. The traditional approach assumes that interfaces between layers are frictionless and layers can slip past one another freely as they deflect. In contrast, the design of structural laminated beams has traditionally been based on the assumption that the interfaces between layers were welded, with no slip occurring there. In this work, the theory of composite laminated beams, which allows for partial slip on layer interfaces, is applied to the problem of predicting displacements and stresses in layered roof rock. The effects of rockbolt reinforcement are modeled by discrete shear and normal stiffnesses incorporated at locations in the model where the rockbolts cross layer interfaces. Published solutions and results for laminated composite beams are reviewed. Composite laminated beam theory provided a means of accounting for rockbolt reinforcement effects and provided a conceptual framework that was used to develop two FORTRAN programs; one, based on the force method of analysis, that automatically finds shear and tensile interface failures in the system, and the other a finite element program that employs beam elements, elastic interface elements, and rockbolt elements to model a rockbolted layered rock system. Published data together with results from these programs suggest that shear reinforcement may be more effective when placed near the ends of roof layers. The normal interaction between layers tends to be uniformly distributed unless rockbolt forces act on the layers or if partial delamination of layers has occurred. Both shear and normal reinforcement will cause stresses to be redistributed within the system of layers. Analysis of this redistribution of stresses requires that the sequence of interface failure be predicted which, in turn, requires that the properties of the individual layers, of the interfaces between layers, and of the rockbolts be properly taken into account. Laminated composite beam theory and programs based on this theory provide rational and efficient ways to study and analyze the behavior of layered roof rock.

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7

Islam, Mohammad Aminul. „Constitutive modeling and plastic analysis with application to beam-to-column connections“. Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184486.

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Analysis and design of connections, such as beam-to-column connections, pose various complexities such as nonlinear behavior of material and geometric condition, irregularities in geometry and boundary condition. The main purpose of these types of connections is to provide adequate structural strength and a sufficiently stiff structure at working loads, and to possess sufficient ductility and strength at overloads such as may occur during a major earthquake. At present the design profession does not have established guidelines for estimating the ultimate moment and shear capacity of these connections. The assumption of linear elastic material behavior of the connections is no longer valid when the elements are stressed beyond the yield stress of the material. For such problems encountered in the design of typical structures, either the closed-form analytical solutions are extremely complex or cannot be obtained at all. Thus, numerical techniques such as finite difference, finite element and boundary integral methods are used. In this study, a finite element program is developed for plastic analysis of connections such as beam-to-column connection using a constitutive law of the material, a three parameter stress-strain relationship, which gives stress explicitly in terms of strain. One hundred and fifteen cases of beam-to-column connections subjected to moment are analysed with the finite element program developed in this study, and the results are compared with the existing approximate solution by yield line theory to propose a simple formula to correlate actual ultimate capacity to the approximate solution.

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8

Tong, Wenxia 1958. „Finite element analysis of continuous prestressed composite girders“. Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/277224.

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Prestressing a steel girder reduces the required structural steel weight, limits tension stresses in the section, increases the ultimate strength, and increases the fatigue resistance. The technique of prestressing with tendons can be used for strengthening of existing bridges as well as for construction of new bridges. This thesis presents an analytical study of the behavior of simply-supported and continuous prestressed composite girders and describes the benefits of prestressing steel in composite construction. Analytical models are developed and used as a basis for a computer program that calculates the stresses and displacements in the cables and the girder at discrete number of nodes along the length of the girder. The effects of design variables such as prestress force, tendon profile, eccentricity and tendon length are studied. The results indicate that prestressing is an effective means of increasing the load carrying capacity of simple-span as well as continuous composite girders.

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9

Le, Gall Carole A. „Thermomechanical stress analysis of flip chip packages“. Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/16002.

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10

楊貴永 und Kwai-wing Yeung. „Elastic-plastic analysis of rolling elliptical contacts and the effects of axial superimposed stresses on rolling contact fatiguefailure“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1987. http://hub.hku.hk/bib/B31231032.

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11

Yeung, Kwai-wing. „Elastic-plastic analysis of rolling elliptical contacts and the effects of axial superimposed stresses on rolling contact fatigue failure /“. [Hong Kong] : University of Hong Kong, 1987. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12333669.

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12

Khalili, Amin. „Stress and deformation analysis of rotating discs : a dissertation presented to the faculty of the Graduate School, Tennessee Technological University /“. Click to access online version, 2006. http://proquest.umi.com/pqdweb?index=102&did=1155566681&SrchMode=1&sid=1&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1257361554&clientId=28564.

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13

Gardner, Brian Michael. „Visualization and stress analysis of complex three-dimensional structures“. Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/17382.

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14

Wong, Koon-yui, und 黃冠睿. „Strain analysis of displacement data from the pos selim landslide“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45161811.

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15

陳永堅 und Wing-kin Chan. „Formulation of solid elements for linear and geometric nonlinear analysis of shells“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B30252842.

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16

FRANTZISKONIS, GEORGE NIKOLAOS. „PROGRESSIVE DAMAGE AND CONSTITUTIVE BEHAVIOR OF GEOMATERIALS INCLUDING ANALYSIS AND IMPLEMENTATION“. Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183838.

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In this dissertation, first the experimental and theoretical observations on the deformational characteristics of brittle geomaterials are reviewed and discussed. A basic conclusion is that special features such as strain softening can not be considered as true material (continuum) properties. These conclusions created a renewed emphasis on the constitutive modelling of such materials. A model that accounts for structural changes is developed. Such changes are incorporated in the theory through a tensor form of a damage variable. It is shown subsequently that formation of damage is responsible for the degradation in strength (softening) observed in experiments, for the degradation of the elastic shear modulus and for mechanical, damage induced anisotropy. A generalized plasticity model is incorporated for the so-called topical or continuum part of the behavior, whereas the damage part is represented by the so-called stress-relieved behavior. The question of uniqueness in the strain-softening regime is examined. It is shown that the constitutive equations lead to a unique solution for the case of rate dependent as well as rate independent formulation. Its implementation in finite element analysis shows mesh size insensitivity in the hardening and softening regimes. The general order of bifurcation of differential equations is employed in order to study the effect of damage accumulation on formation of narrow, so-called shear bands. It is shown that as the damage accumulates, the material approaches localization of deformation. The theory of mixtures is employed for further theoretical establishment of the proposed model. Energy considerations show the equivalence of the two-component damage body to an elastoplastic body containing cracks; the equivalence is considered in the Griffith sense. The mechanisms of failure are considered and discussed with respect to multiaxial stress pads. An explanation of failure, at the micro level, is given. The material constants involved in the theory are identified and determined from available experimental data. The model is then verified by back-predicting the observed behavior.

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17

Javidinejad, Amir. „An experimental stress analysis approach for pure shear testing and analysis of a fiber reinforced plastic composite“. Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/20706.

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18

鍾偉昌 und Wai-cheong Chung. „Geometrically nonlinear analysis of plates using higher order finite elements“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1986. http://hub.hku.hk/bib/B31207601.

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19

Chung, Wai-cheong. „Geometrically nonlinear analysis of plates using higher order finite elements /“. [Hong Kong : University of Hong Kong], 1986. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12225022.

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20

Zhou, Ding, und 周叮. „Three-dimensional vibration analysis of structural elements using Chebyshev-Ritz method“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B27511200.

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21

Watts, Michael Robert. „The analysis of diffraction measurements of internal strains in metal matrix composites“. Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313918.

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22

Xia, Qingxi. „Numerical and experimental analysis of the dynamic behavior of concrete and mortar“. Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/18981.

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23

Kalpundi, Ganesh R. „Nonlinear mixed finite element analysis for contact problems by a penalty constraint technique“. Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06302009-040252/.

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24

Radhakrishnan, Sadhana. „Stress Analysis of Embedded Devices Under Thermal Cycling“. PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4075.

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Embedded active and passive devices has been increasingly used by in order to integrate more functions inside the same or smaller size device and to meet the need for better electrical performance of the component assemblies. Solder joints have been used in the electronic industry as both structural and electrical interconnections between electronic packages and printed circuit boards (PCB). When solder joints are under thermal cyclic loading, mismatch in coefficients of thermal expansion (CTE) between the printed circuit boards and the solder balls creates thermal strains and stresses on the joints, which may finally result in cracking. Consequently, the mechanical interconnection is lost, leading to electrical failures which in turn causes malfunction of the circuit or whole system. When a die is embedded into a substrate, Young's modulus of the die is larger than one of the core of the substrate and the CTEs of the die is smaller than those of the substrate. As a result, mismatch in coefficients of thermal expansions (CTE) between the substrate with the embedded device and the solder balls may increase. In the present study, finite element method (FEM) is employed to find out the stress and strain distribution of ball grid array(BGA) solders under thermal cycling. The ANAND model for viscoplasticity is employed for this purpose.

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25

Subramaniam, Mahesh Kumar. „A computer implementation of the static and dynamic analysis of induced strain actuated beams“. Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-01242009-063044/.

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26

Warren, Alexander V. R. „Empirical shear assessment of reinforced concrete bridge members“. Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=25876.

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27

Palaniappan, Prema. „In-process stress analysis of flip chip assemblies during underfill cure and environmental stress testing“. Thesis, Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/19138.

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28

Marcus, Khalid Behnam. „TWO-DIMENSIONAL FINITE ELEMENT ANALYSIS OF FLOW NEAR A BRIDGE IN A COMPLEX FLOOD PLAIN“. Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275268.

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29

Lau, Chung Yin. „Computational stress analysis for ball grid array reliability and passive component reliability in board level assemblies /“. View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?MECH%202005%20LAU.

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30

Tsai, Ming-Yi. „Application of localized hybrid methods of stress analysis to some problems in the mechanics of composites“. Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/39697.

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31

Halepli, A. R. (A Reymond). „A comparative dynamic and static stress analysis of a prosthetically resurfaced tibia /“. Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63331.

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32

Xin, Xudong. „An analytical and numerical analysis of dynamic failure based on the multi-physics involved /“. free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3025668.

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33

朱達善 und Dashan Zhu. „Nonlinear static and dynamic analysis of plates & shells by spline finite strip method“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1988. http://hub.hku.hk/bib/B31231743.

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34

Zhu, Dashan. „Nonlinear static and dynamic analysis of plates & shells by spline finite strip method /“. [Hong Kong] : University of Hong Kong, 1988. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12427020.

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35

Alemdar, Bulent Nedim. „Distributed plasticity analysis of steel building structural systems“. Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/22220.

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36

Zhao, Huyue. „Stress Analysis of Tapered Sandwich Panels with Isotropic or Laminated Composite Facings“. Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/ZhaoH2002.pdf.

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37

SUBRAMANIAN, BALAKRISHNAN. „GEOMETRICALLY NONLINEAR ANALYSIS OF THIN ARBITRARY SHELLS USING DISCRETE-KIRCHHOFF CURVED TRIANGULAR ELEMENTS (FINITE)“. Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188101.

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The research work presented here deals with the problems of geometrically nonlinear analysis of thin shell structures. The specific objective was to develop geometrically nonlinear formulations, using Discrete-Kirchhoff Curved Triangular (DKCT) thin shell elements. The DKCT elements, formulated in the natural curvilinear coordinates, based on arbitrary deep shell theory and representing explicit rigid body modes, were successfully applied to linear elastic analysis of composite shells in an earlier research work. A detailed discussion on the developments of classical linear and nonlinear shell theories and the Finite Element applications to linear and nonlinear analysis of shells has been presented. The difficulties of developing converging shell elements due to Kirchhoff's hypothesis have been discussed. The importance of formulating shell elements based on deep shell theory has also been pointed out. The development of shell elements based on Discrete-Kirchhoff's theory has been discussed. The development of a simple 3-noded curved triangular thin shell element with 27 degrees-of-freedom in the tangent and normal displacements and their first-order derivatives, formulated in the natural curvilinear coordinates and based on arbitrary deep shell theory, has been described. This DKCT element has been used to develop geometrically nonlinear formulation for the nonlinear analysis of thin shells. A detailed derivation of the geometrically nonlinear (GNL) formulation, using the DKCT element based on the Total Lagrangian approach and the principles of virtual work has been presented. The techniques of solving the nonlinear equilibrium equations, using the incremental methods has been described. This includes the derivation of the Tangent Stiffness matrix. Various Newton-Raphson solution algorithms and the associated convergence criteria have been discussed in detail. Difficulties of tracing the post buckling behavior using these algorithms and hence the necessity of using alternative techniques have been mentioned. A detailed numerical evaluation of the GNL formulation has been carried out by solving a number of standard problems in the linear buckling and GNL analysis. The results compare well with the standard solutions in linear buckling cases and are in general satisfactory for the GNL analysis in the region of large displacements and small rotations. It is concluded that this simple and economical element will be an ideal choice for the expensive nonlinear analysis of shells. However, it is suggested that the element formulation should include large rotations for the element to perform accurately in the region of large rotations.

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38

Cocle, Jennifer. „Development of the EBSD Intensity Response for Quantitative Strain Analyses of Materials“. Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=93017.

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Electron BackScattered Diffraction (EBSD) systems can be considered as a tool providing three kinds of responses: EBSD patterns (EBSPs) themselves, an indexing response (orientation data), and an intensity response (also called Band Contrast "BC", Image Quality "IQ", or Pattern Quality "PQ or P"). This work focused on the characterization and development of the intensity response. For now, the intensity response cannot be used for quantitative microstructural analyses, including strain analyses of materials. Indeed, this response is affected by several material and experimental conditions. Moreover, properties of the intensity response (strain sensitivity, reproducibility, exact relation with EBSP quality or diffraction band intensities) are not well-known and understood. This project constitutes an exploratory study on the development of the intensity response for quantitative strain analyses of materials. A new modelling and statistical approach is presented and assessed for transforming the raw (current) intensity response (values and grey-tones of intensity images) of commercial EBSD systems into an accurate and reproducible parameter allowing objective visualization and measurements of strain.
Les systèmes de diffraction des électrons rétro-diffusés (EBSD) peuvent être considérés comme un outil offrant trois types de réponses: les patrons EBSD (EBSPs), la réponse d'indexation (données d'orientation) et la réponse d'intensité (aussi appelée Contraste de Bande «BC », Qualité d'Image « IQ », ou Qualité de Patron « PQ ou P »). Le présent projet s'est concentré sur la caractérisation et le développement de la réponse d'intensité. En effet, pour l'instant, la réponse d'intensité ne peut être utilisée pour réaliser des analyses microstructurales quantitatives des matériaux. En effet, cette réponse est influencée par de nombreux facteurs relatifs au matériau analysé et aux conditions expérimentales utilisées. De plus, les propriétés de la réponse d'intensité (sensibilité à la déformation, reproductibilité, relation exacte avec la qualité des EBSPs ou les intensités des bandes de diffraction) ne sont pour l'instant pas bien connues ni même compnses. Le présent projet représente donc une étude exploratoire visant le développement de la réponse d'intensité des systèmes EBSD commerciaux pour l'analyse quantitative de la déformation des matériaux. Dans ce projet, une approche de modélisation statistique est présentée et évaluée afin de transformer la réponse d'intensité actuelle (valeurs et tons de gris des images d'intensité) des systèmes EBSD commerciaux en une réponse précise et reproductible permettant de visualiser et de mesurer objectivement la déformation.

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39

Harrison, Peter Newton. „Interlaminar stress analysis of dropped-ply laminated plates and shells by a mixed method“. Diss., Virginia Tech, 1994. http://hdl.handle.net/10919/39735.

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A mixed method of approximation based on Reissner's variational principle is developed for the linear analysis of interlaminar stresses in laminated composites, with special interest in laminates that contain terminated internal plies (dropped-ply laminates). Two models are derived, one for problems of generalized plane deformation and the other for the axisymmetric response of shells of revolution. A layerwise approach is taken in which the stress field is assumed with an explicit dependence on the thickness coordinate in each layer. The dependence of the stress field on the thickness coordinate is determined such that the three-dimensional equilibrium equations are satisfied by the approximation. The solution domain is reduced to one dimension by integration through the thickness. Continuity of tractions and displacements between layers is imposed. The governing two-point boundary value problem is composed of a system of both differential and algebraic equations (DAEs) and their associated boundary conditions. Careful evaluation of the system of DAEs was required to arrive at a form that allowed application of a one-step finite difference approximation. A two-stage Gauss implicit Runge-Kutta finite difference scheme was used for the solution because of its relatively high degree of accuracy. Patch tests of the two models revealed problems with solution accuracy for the axisymmetric model of a cylindrical shell loaded by internal pressure. Parametric studies of dropped-ply laminate characteristics and their influence on the interlaminar stresses were performed using the generalized plane deformation model Eccentricity of the middle surface of the laminate through the ply drop-off was found to have a minimal effect on the interlaminar stresses under longitudinal compression, transverse tension, and in-plane shear. A second study found the stiffness change across the ply termination to have a much greater influence on the interlaminar stresses. Correlations between the stiffness ratio of the thick to the thin sections of the laminates and the magnitude of a parameter based on a quadratic delamination criterion were found to be surprisingly good for longitudinal compression and in-plane shear loadings. For laminates with very stiff terminated plies loaded in longitudinal compression, inclusion of a short insert of softer composite material at the end of the dropped plies was found to significantly reduce the interlaminar stresses produced.
Ph. D.

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40

Kumara, Mampe Arachchige Wasantha. „Analysis and verification of stresses and strains and their relationship to failure in concrete pavements under heavy vehicle simulator loading“. [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010099.

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41

Koeneman, Paul Bryant. „Viscoelastic stress analysis and fatigue life prediction of a flip-chip-on-board electronic package /“. Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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42

Lantz, Gabriel Antoine. „Crack detection using a passive wireless strain sensor“. Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45773.

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Nearly one third of the 604,426 bridges in the United-States are either structurally deficient or functionally obsolete. Monitoring these bridges is essential to avoid catastrophic accidents. In steel bridges fatigue induced crack/rupture, which is one of the most common modes of failure, can be avoided if the crack is detected at the early stages of its formation. Cracks usually originate at stress concentration areas but their precise origin is random. Such strain concentration can be monitored with traditional strain gages, but their installation requires lengthy wires and equipment, which are expensive and labor intensive. Therefore wireless sensors are being developed to cope with these problems. In this work, a passive wireless strain sensor based on RFID technology is described. The sensor is a patch antenna that resonates at a certain frequency, which shifts in presence of strain. The relation between the resonance frequency and the strain is approximately linear. The slope of the relation is called sensitivity. The behavior of the sensor's sensitivity is studied using experimental work and simulations that couple electromagnetism and mechanics. The sensitivity measured in experiments and in simulations in presence of uniform strain is different. This difference is lower for the sensitivity in presence of a crack, probably due to a parameter variation that is currently not accurately modeled in the simulations.

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43

Cross, Benjamin Thomas. „Analysis of the AASHTO fatigue design provisions for welded steel bridge details using reliability theory“. Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 101 p, 2007. http://proquest.umi.com/pqdweb?did=1338919111&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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44

Flaccus, Christopher Edward 1953. „Stress on the San Andreas fault: an analysis of shallow stress relief measurements made near Palmdale, California, 1979 and 1980“. Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/558088.

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45

Fink, Elliot G. „A stress-based fatigue life evaluation of two steel bridges along I-95 in Delaware“. Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 3.03 Mb., ? p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:1435862.

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46

Louchnikov, Vadim. „A numerical investigation into the stress memory effect in rocks“. Click here to access, 2004. http://hdl.handle.net/2440/37740.

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Reliable and inexpensive methods of in-situ stress measurement have been sought for more than 40 years. A number of non-destructive core-based methods of in-situ stress determination are currently available, among which Deformation Rate Analysis ' DRA ' and Acoustic Emissions ' AE ' method have the most promising potential due to their ability to measure stress as opposed to strain, which is measured by strain recovery techniques. The DRA and AE method are similar in their utilisation of a phenomenon termed Kaiser effect in the case of AE and deformation memory effect in the case of DRA. The KE/DME is defined as a recollection of a maximum stress a rock core had been subjected prior to its retrieval from the in-situ environment. The physical nature of this phenomenon has not however been universally established. In this study, interaction of microcracks as the most probable cause of the KE/DME, was investigated. To reproduce the damage that occurs to rock at the micro level, a discrete element modelling code was required, which enabled dynamic failure propagation to be modelled. Commercially available code PFC [ superscript 2D ] was found to be suitable for this purpose due to its ability to explicitly model mechanical damage in rocks. The numerical model was based on a real prototype - a sandstone rock core, which had also been previously subjected to the DRA. Although the bulk of the numerical tests were conducted on intact rock models, it was found that changes in the lithology and introduction of discontinuities did not have significant effect on the DME. Influence of the confining stress on the DME was confirmed. It was assumed that only the highest historical stress could be determined reliably using the DRA technique. The ability of the numerical model to reproduce the DME was validated. The link between the DME and development of microcracks was established. The results of the study encourage further use of the code for understanding the micromechanical behaviour of rocks under loading.
Thesis (M.Eng.Sc.)--Australian School of Petroleum, 2004.

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WILLIAMS, GEORGE CLAY. „STEEL CONNECTION DESIGNS BASED ON INELASTIC FINITE ELEMENT ANALYSES (GUSSET, BRACING, STRUCTURES)“. Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/188168.

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Analytical and experimental studies were made to develop design procedures for steel gusset plate connections in diagonally braced frames. Stiffness and strength models of structural fasteners based on physical tests were incorporated into inelastic finite element analyses. The modeling techniques were verified by comparing analytical and experimental results of full scale connection tests. Finite element models of bracing connections were generated to determine gusset plate force, stress, strain, and displacement distributions for a variety of connection designs including K-bracing and X-bracing. Based on these results current design procedures were scrutinized and new design procedures were proposed for predicting the tensile strength, buckling strength, and force distributions for bracing connections. Additionally, it was found that gusseted beam-to-column connections are rigid (AISC Type I) and the centroidal axes of the brace, beam, and column members do not necessarily need to intersect at a common working point.

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Williams, Walter Ray. „Stress analysis of a glued timber beam“. Master's thesis, Mississippi State : Mississippi State University, 2009. http://library.msstate.edu/etd/show.asp?etd=etd-04032009-085801.

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Ye, Wei. „Nano-heteroepitaxy stress and strain analysis: from molecular dynamic simulations to continuum methods“. Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34752.

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For decades, epitaxy is used in nanotechnologies and semiconductor fabrications. So far, it's the only affordable method of high quality crystal growth for many semiconductor materials. Heterostructures developed from these make it possible to solve the considerably more general problem of controlling the fundamental parameters inside the semiconductor crystals and devices. Moreover, as one newly arising study and application branch of epitaxy, selective area growth (SAG) is widely used to fabricate materials of different thicknesses and composition on different regions of a single wafer. All of these new and promising fields have caught the interests and attentions of all the researchers around the world. In this work, we will study the stress and strain analysis of epitaxy in nano-scale materials, in which we seek a methodology to bridge the gap between continuum mechanical models and incorporate surface excess energy effects, which can be obtained by molecular dynamical simulations. We will make a brief description of the elastic behavior of the bulk material, covering the concepts of stress, strain, elastic energy and especially, the elastic constants. After that, we explained in details about the definitions of surface/interface excess energy and their characteristic property tensors. For both elastic constants and surface excess energy, we will use molecular dynamic simulations to calculate them out, which is mainly about curve-fitting the parabola function between the total strain energy density and the strain. After this, we analyzed the stress and strain state in nanoisland during the selective area growth of epitaxy. When the nanoisland is relaxed, the lattice structure becomes equilibrated, which means the total strain energy of system need to be minimized. Compared to other researcher's work, our model is based on continuum mechanics but also adopts the outcome from MD simulations. By combining these microscopic informations and those macroscopic observable properties, such as bulk elastic constants, we can provide a novel way of analyzing the stress and strain profile in epitaxy. The most important idea behind this approach is that, whenever we can obtain the elastic constants and surface property tensors from MD simulations, we can follow the same methodology to analyse the stress and strain in any epitaxy process. This is the power of combining atomistic simulations and continuum method, which can take considerations of both the microscopic and macroscopic factors.

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Naude, Francois Paulus. „Development of a methodology for calculating stresses in track components“. Diss., Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-07282005-090746.

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Dissertationen zum Thema „Strains and stresses – Analysis“

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