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This diploma thesis deals with the analysis of stress and strain burdened road construction. Comparison of dimensioning using programs LayEps and Alize and introduction modules of this program.

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This thesis is concerned with both the static and dynamic analysis of parabolic arches. In the dynamic part, special attention is given to the free vibration of such arches. The following procedure is followed. The loading conditions are assumed and a infinitesimal segment of the arch is taken so as the differential equations relating deflections and slope changes on both ends of the segment are developed. These obtain a set of general equations for elastic parabolic arches. In dynamics, the equations of general curved structure are developed through considerations of dynamic equilibrium. A sudden removal of loading is assumed to cause the structure to vibrate freely. Then, a method of separating variables for partial differential equations is used to get the equations of deflection components. Each special characteristic function is derived for each special set of boundary conditions so as to get an unlimited number of modes of free vibrations. The Fourier series is employed to determine the coefficients of the dynamic equations, and to get a series-form solution for deflections. Finally, two numerical examples are given to represent the practical application. Two kinds of parabolic arches, one with two-hinged supports and the other with fixed-ends are considered in each procedure. / Master of Science

Since the Eighteenth century, a great amount of research has been done using the elastic analysis technique in the field of curved structures. Recently the question of behavior beyond the yielding range has become increasingly important. By applying the methods of plastic analysis, the collapse load of a structure can be determined, and also the stress distribution and the deflection, just before collapse, can be calculated. However the evolution of the stress distribution and the deflection at any section of the structure between the load causing first yielding and the collapse load is still an unsolved problem. Concerning the problem of evolution of the stress distribution in the inelastic range, most literature relies on the simple plastic theory in which the effect of the axial force on the formation of a plastic hinge is neglected. In fact this conception is in serious error in some cases, especially when the curved structure is a shallow arch, the stresses developed are apparently governed by the axial force. Literature considering the combined effects of bending moment and axial force is very rare. In this thesis, the author proposes a new method, incorporating effects of both axial force and bending moment, of determining the evolution of stress distributions and the deflections in the inelastic range. The thesis includes three parts. In the first to parts, the theory for the stress analysis and for the deflection of a rectangular section is presented. The third part contains three examples to illustrate the use of the new method in practical engineering problems. / Master of Science

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For microelectronics used in the low-temperature applications, the understanding of their reliability and performance has become an important research subject characterised as electronics to serve under the severe or extreme service conditions. Along with the impact from the increased miniaturization of devices, the various properties and the relevant thermo-mechanical response of the interconnection materials to temperature excursion at micro-scale become a critical factor which can affect the reliable performance of microelectronics in various applications. Pure indium as an excellent interconnection material has been used in pixellated detector systems, which are required to be functional at cryogenic temperatures. This thesis presents an extensive investigation into the thermo-mechanical properties of indium joints as a function of microstructure, strain (loading histories-dependent) and temperature (service condition-sensitive), specifically in the areas as follows: (i) the interfacial reactions and evolution between indium and substrate during the reflow process (liquid-solid) and thermal aging (solid-solid) stages by taking low-temperature cycling into account; (ii) determination of the effects of joint thickness and the types of substrate (e.g. Cu or Ni) on the mechanical properties of indium joints, and the stress- and temperature-dependent creep behaviour of indium joints; (iii) the establishment of a constitutive relationship for indium interconnects under a wide range of homologous temperature changes that was subsequently implemented into an FE model to allow the analysis of the evolution of thermally-induced stresses and strains associated with a hybrid pixel detector.

Mechanical ventilation has been a major therapy used by physicians in support of surgery as well as for treating patients with reduced lung function. Despite its many positive outcomes and ability to maintain life, in many cases, it has also led to increased injury of the lungs, further exacerbating the diseased state. Numerous studies have investigated the effects of long term ventilation with respect to lungs, however, the connection between the global deformation of the whole organ and the strains reaching the alveolar walls remains unclear. The walls of lung alveoli also called the alveolar septum are characterized as a multilayer heterogeneous biological tissue. In cases where damage to this parenchymal structure insist, alveolar overdistension occurs. Therefore, damage is most profound at the alveolar level and the deformation as a result of such mechanical forces must be investigated thoroughly. This study investigates a three-dimensional lung alveolar model from generations 22 (alveolar ducts) through 24 (alveoli sacs) in order to estimate the strain/stress levels under mechanical ventilation conditions. Additionally, a multilayer alveolar tissue model was generated to investigate localized damage at the alveolar wall. Using ANSYS, a commercial finite element software package, a fluid-structure interaction analysis (FSI) was performed on both models. Various cases were simulated that included a normal healthy lung, normal lung with structural changes to model disease and normal lung with mechanical property changes to model aging. In the alveolar tissue analysis, strains obtained from the aged lung alveolar analysis were applied as a boundary condition and used to obtain the mechanical forces exerted as a result. This work seeks to give both a qualitative and quantitative description of the stress/strain fields exerted at the alveolar region of the lungs. Regions of stress/strain concentration will be identified in order to gain perspective on where excess damage may occur. Such damage can lead to overdistension and possible collapse of a single alveolus. Furthermore, such regions of intensified stress/strain are translated to the cellular level and offset a signaling cascade. Hence, this work will provide distributions of mechanical forces across alveolar and tissue models as well as significant quantifications of damaging stresses and strains.

Analisam-se a variação de parâmetros obtidos da curva tensão-deformação dos solos, interpretada como uma hipérbole, em função dos parâmetros de compactação obtidos da curva de compactação Proctor Normal. Esta análise é feita em três solos típicos. / The variation of the parameters obtained by the stress-strain curve of the soils, understood as a hyperbola is analysed in function of the compactation parameters obtained from the Proctor Compactation Curve. This analysis is made with three typical soils.