Structural shape optimization using MSC/NASTRAN and sequential quadratic programming

This work is a continuation of a work done by the authors on sizing optimization where the structure is optimized with respect to the thickness. In this work shape optimization is performed. The implementation is described and a comparison has been made between three different methods for sensitivity analysis calculation. An efficient coupling with an optimization module and the commercial finite element package MSC/NASTRAN using DMAP (direct matrix abstraction program) is made. A sequential quadratic programming algorithm is used for optimization. Differences in the implementation of these sensitivity analysis methods as well as advantages and disadvantages are outlined. In order to give a practical comparison between the three methods and to demonstrate the feasibility of the proposed methodology, the shape optimization of a disk with a hole at the center and a unit injector rocker arm are presented as examples. (C) 1999 Elsevier Science Ltd. All rights reserved.