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For practical engineering purpose, a new flat shell element baptized (ACM_Q4SBE1) is presented in this paper. The formulated element can be used for the analysis of thin shell structures; no matter how the geometrical shape might be. Tests on standard problems have been examined. Since, the analysis of thin shell structures has generally been purely carried out on a theoretical basis; it is of importance to present some experimental results of an elliptical paraboloid under uniformly distributed load pressure. The results obtained from both numerical and experimental work are presented. [ABSTRACT FROM AUTHOR]

The fatigue is the most common way of structural imperfection and, over the time, it has been a problem to the imposed requests and the type of applied load. In this paper, there is a study of the way the resistance fatigue ASTM A-36 is made among two environments: refrigerated and immerged into water at 5 atm hydrostatic pressure through bending tension fatigue tests. After that, some analyses and comparative results with the tested material were carried out. For this study, a mechanism was developed to test fatigue for bending tension to be used inside and outside hyperbaric chamber for the hydrostatic pressure simulation. This study is worth because any resistance confirmation does not exist in immerged fatigue of virgin materials; in other words, all the tests of fatigue were or have being accomplished in materials done in the air. Curves S-N were determined for each atmosphere. The methodology used for verification of resistance to the fatigue was the regression model from a data originated from accelerated life tests and it was possible to verify the environment influence in the phenomenon of the fatigue. [ABSTRACT FROM AUTHOR]

In order to obtain a suitable rigid implant, we need to be certain that its properties are very close to the structure it is supposed to replace or support. For this reason, the materials to be used for manufacturing should be carefully selected, so that their mechanical and biomechanical properties correspond to the intended purpose. The present paper is dealing with some impact tests developed for these types of structures and the required testing methodology. [ABSTRACT FROM AUTHOR]

In this paper, elasto-plastic analysis of an edge crack has been performed using element free Galerkin method. A model problem has been solved in plane stress condition under mode-I loading. A system of nonlinear equations has been obtained by using incremental theory of plasticity, and the equations are solved by assuming piecewise linear approximation. A code has been written in Matlab for elastoplastic analysis of cracked components. The size of plastic zone is calculated around the tip of the crack by EFGM code. [ABSTRACT FROM AUTHOR]

Since the evaluation of each individual is based on the time-consuming structural analysis, the computational efficiency of truss topology optimization using genetic algorithm is very low. The paper focuses on this challenging problem. It is observed that there are a number of duplicate individuals appearing repetitively in the evolutionary process. Therefore, an individual identification technique is introduced to avoid evaluating the duplicate individuals by the time-consuming structural analysis but by searching the evolutionary history data to save computing time, the computational complexity of this technique is deduced. The results of two truss examples verify that the technique can effectively improve the efficiency of the algorithm. Based on this identification technique, numeric experiments are implemented to study the influence of several factors, i.e., the population size, the max generation, and the scale of problems, on the proportion of duplicate individuals. Results show that the population size has a significant impact on the proportion, and that both the max generation and the scale of problems have little influence. [ABSTRACT FROM AUTHOR]

The motivation for this paper is to develop an approach to optimization of beam design. Under given loading and support conditions, the comparative strength of three (3) common structural shapes was determined. This led to the conclusion that a particular structural shape together with its dimensions will give the optimal solution in beam design in terms of the least cross-sectional area to support the given load, which would then translate to savings in cost and reduction in weight of the structural member. An investigation was also conducted to take into consideration the effect in the dimensions of the structural shapes of uncertainties due to manufacturing limitations and tolerances. This resulted in an assessment of the order of magnitude of this effect on the design variables. In solving the resulting optimization problems, MATLAB's Genetic Algorithm and Direct Search Toolbox was employed. [ABSTRACT FROM AUTHOR]

Chapter 8 of the book "Casing and Liners for Drilling and Completion," by Ted G. Byrom is presented. It discusses formulas for calculating casing strength as well as notes calculations in examining the effects of loading, lateral instability or buckling, and the thermal effects on casing design. Other current formulas and proposed changes are also given.