Improvements on objective and constraint functions in domain optimization

In this paper a sequential quadratic programming algorithm is efficiently coupled with the finite element package MSC/NASTRAN in order to optimize the shape of two-dimensional parts with piecewise constant thickness, where linearized elasticity is used. Three different methods for gradient calculation with respect to the changing of the shape are also coupled to MSC/NASTRAN. The aim of this article is to give a study on difficulties in the convergence of the shape using usual objective and constraint functions and improvements on them to avoid these difficulties. Two examples are presented to illustrate the improvements made and to give numerical results.