Application of a gradient-based algorithm to structural optimization

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2009.Includes bibliographical references (leaves 175-180).Optimization methods have shown to be efficient at improving structural design, but their use is limited in the engineering practice by the difficulty of adapting state-of-the-art algorithms to particular engineering problems. This study proposes the use of a robust gradient-based algorithm, whose adaptation to a variety of design problems is more straightforward. The algorithm was first applied to truss geometry and beam shape optimization, both forming part of the increasingly popular class of structural form-finding problems. The results showed that the gradient-based method is an appropriate tool for defining shapes in structures. The robustness of the algorithm was verified, as a series of structural configurations were treated with similar efficiency. The gradient-based method was also applied to a more traditional structural design problem through the optimization of a steel girder, resulting in a hybrid scheme featuring a truss stiffener. Throughout the study, emphasis was laid on the practical computer implementation of the gradient-based algorithm in interaction with structural analysis tools.by Pierre Ghisbain.S.M