NUMERICAL COMPARISON BETWEEN 2 COST-FUNCTIONS IN CONTACT SHAPE OPTIMIZATION

A finite element approach to shape optimization in a 2D frictionless c ontact problem for two different cost functions is presented in this w ork. The goal is to find an appropriate shape for the contact boundary , performing an almost constant contact-stress distribution. The whole formulation, including the mathematical model for the unilateral prob lem, sensitivity analysis and geometry definition is treated in a cont inuous form, independently of the discretization in finite elements. S hape optimization is performed by a direct modification of the geometr y through B-spline curves and an automatic mesh generator is used at e ach new configuration to provide the finite element input data. Augmen ted-Lagrangian techniques (to solve the contact problem) and an interi or-point mathematical-programming algorithm (for shape optimization) a re used to obtain numerical results.