Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin, 1947. / Typewritten. eContent provider-neutral record in process. Description based on print version record.

Thesis (M.S.)--University of Wisconsin, 1950. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 69-78).

Thesis (M.S. in civil engineering)--Washington State University, December 2006. / Includes bibliographical references (p. 165-168).

Thesis (Ph. D.)--Washington State University, August 2007. / Includes bibliographical references.

Thesis (Ph. D.)--University of Chicago, Dept. of Physics, March 2001. / Includes bibliographical references. Also available on the Internet.

Shear walls are one of the most effective methods of resisting these lateral forces caused by seismic or wind load. The placement of these walls can be very influential on how the structure behaves. Since the end return of a shear wall is perpendicular to the lateral force, it is neglected for the purpose of resisting later force. This study will investigate whether or not the effect of end return on the rigidity of shear walls can be neglected. Two different building frames will be modeled using Finite Element Analysis software to see how they behave differently. Hand calculations will also be incorporated to check and verify the results obtained by the computer models. The moment of inertia is expected to be an important factor calculating the deflection of the shear wall due to bending, and the end return may significantly impact the magnitude of the moment of inertia. The objective of this study is to determine the effect of the end return on the rigidity of a shear wall.

Orientador: Marcos Tadeu Tibúrcio Gonçalves / Co orientador: Claudio De Conti / Banca: Ivaldo de Domenico Valarelli / Banca: Marcelo dos Santos Pereira / Resumo: O ensaio de tração fora do eixo de simetria, conhecido como ensaio off-axis, trata-se de um método utilizado para identificação do comportamento ao cisalhamento de um determinado material. Neste ensaio os eixos de simetria do material fazem um ângulo com os eixos do corpo de prova. Este ensaio foi proposto com o intuito de extrair o efeito não uniforme da distribuição de tensões que ocorrem no centro do corpo de prova, que naturalmente estão presentes nos ensaios normalizados para o cisalhamento. Os ensaios normalizados consideram a hipótese das tensões serem distribuídas uniformemente, porém desde que o material começa a cisalhar e até a ruptura esta situação não ocorre nestas condições. A proposta deste trabalho é investigar o comportamento ao cisalhamento da madeira de Eucalyptus citriodora através do ensaio off-axis. Com o método dos elementos finitos e o programa comercial ANSYS 9.0 ED ®, foi possível fazer uma simulação numérica do ensaio off-axis para a madeira de Eucalyptus citriodora, que trata-se de uma madeira com alta densidade, e com isso avaliar a aplicação deste ensaio para esta espécie de madeira também, pois na literatura encontram-se aplicações deste ensaio somente para madeiras com baixas densidades. Finalmente, com base nos resultados obtido desta simulação, que trata-se de uma abordagem não destrutiva, foi possível realizar o ensaio offaxis para esta espécie de madeira para obter o seu módulo de cisalhamento. Os resultados obtidos com a simulação mostraram que a distribuição das tensões e deformações são homogêneas no centro do corpo de prova e o valor de módulo de cisalhamento obtido é coerente com o resultado obtido na literatura / Abstract: The test off-axis of symmetry, known as test off-axis, it is a method used to identify the shear behavior of the determined material. This test the axis of symmetry of the material make an angle with the axis of the specimen. This test was proposed in order extract the effect is nouniform the stress distribution occurring in center of specimen, that naturally appear standardized tests of the shear. The standardized tests consider the hypothesis tension to be distributed evenly, however the shear until failure doesn't occur under these conditions, due coupling of stress different. The purpose of this study is to investigate the shear behavior of Eucalyptus citriodora through testing off-axis. With the finite element method and the commercial program ANSYS 9.0 ED ®, it was possible to test numerical simulation of off-axis for the timber of Eucalyptus, that it is a timber with high density, and thus evaluate the implementation of this test for this species of wood, too, because in the literature are applications of this test only for woods with low densities. Finally, based on results obtained from this simulation that it is a non-destructive, it was possible to perform the test off-axis for this species of wood to get its shear modulus. The results obtained with the simulation showed that the distribution of stresses and strains are homogeneous at the center of the specimen and the value of shear modulus obtained is consistent with the result obtained in the literature / Mestre

L’objectif principal de la thèse est d’analyser les mécanismes de plasticité et d’endommagement d’une nouvelle famille de composites à matrice acier Fe-TiB₂ afin de comprendre les liens microstructure/propriétés mécaniques et appliquer des modèles de comportement prenant en compte différents paramètres de la microstructure, et d’intérêt pour la mise en forme. L’étude porte sur des nuances de composites à teneur en particules fixée et différant par la taille de grain de la matrice. La caractérisation expérimentale des microstructures et textures initiales par MEB/EBSD et DRX a permis d’analyser qualitativement et quantitativement les différents paramètres morphologiques des renforts et de la matrice. L’effet de taille de grain de la matrice et des renforts sur l’écrouissage des ces composites a été étudié par essais de cisaillement simple monotone et inversés qui ont également permis de déterminer la part relative d’écrouissage cinématique des différents matériaux. L’application des résultats à une modélisation phénoménologique de l’écrouissage a permis de décrire le backstress des composites à partir de celui de la ferrite. L’analyse de l’évolution microstructurale avec la déformation de cisaillement, ainsi que des essais de flexion in situ, ont identifié la rupture des particules comme mode d’endommagement prépondérant des composites Fe-TiB₂. L’endommagement dépend de la taille de grain de la matrice, de d’endommagement des matériaux hétérogènes a permis d’estimer les contraintes de rupture des particules sur la base des résultats expérimentaux disponibles. / The aim of this work was the plasticity and damage mechanisms analysis of a new steel matrix composites Fe- TiB₂ family to establish the microstructure / mechanical properties relationships then interesting for metal forming simulations in respect with various microstructural parameters. The study was focused on composites with different matrix grain size and a given particle population. The experimental characterization of initial microstructures and textures with SEM/EBSD and XRD permitted the qualitative and quantitative analysis of different morphological parameters of reinforcements and the ferritic matrix. The effect of matrix grain size and reinforcements on the composites hardening is studied based on monotonous and reverse simple shear tests which leads to determine the relative contribution of kinematic hardening. The application of a phenomenological modeling based on these results, has successfully describe the composite backstress evolution. Analysis of the microstructural evolution with shear deformation and with four points bending situ tests has shown a sensitivity of Fe-TiB₂ damage to the matrix grain size, the particles size and to the strain-path change. A damage model of heterogeneous material has been then considered and provides the particles failure stress of on the basis of the available experimental results.

This study presents rigid-plastic methods of analysis of shear failure in reinforced concrete (R. C.) wall-beam type structures when subjected to in-plane loading. The upper-bound approach is emphasised. Present shear design practice (e.g. BS8110:1985) relies much upon empirical solutions, but it is inadequately Substantiated by theoretical analyses when compared with design against bending moments. Review of previous work on shear failure in R. C. beams demonstrates the need for a rational analysis approach which broadly represents the important physical characteristics and mechanics of shear failure and which can reliably predict the shear capacity. The rigorous theory of plasticity in shear which was introduced by researchers in Denmark in the early 1970's has proved successful for some limited cases. At failure, a simple kinematic rigid-plastic solution was derived for a stringer model with a straight 'yield line'. Recently, evidence has emerged that the best single yield line between two rigid wall portions may well be curved and not straight. There are different stress states in yield lines and consequently three types of yield line are identified in analysis. These findings enable us to apply for the first time combinations of yield lines to analyse shear failure mechanisms of R. C. wall-beam type structures. The principles of rigid-body plane motion are used to describe the deformations of failure mechanisms. The search for the best mechanism at failure is made automatically by computer. The model predicts reasonably well the strength and mechanism for the test results reported in literature. The model is extended to a wall-beam with openings loaded in plane. Tests were made on shallow beams without shear reinforcement and deep beams with and without web openings to study the accuracy of the fundamental calculations made by the model. The most critical mechanism predicted by the model is reasonably representative of the observed failure mechanism. The strength prediction is in substantial agreement with the experimental tests. The conclusions drawn from the study are: (1) If a correct mechanism is predicted then a rigid-plastic solution is close to the true behaviour otherwise it is an upper bound, and (2) The plastic solution of R. C. is only an approximate solution.