Design of Compliant Mechanisms with Stress Constraints Using Topology Optimization

Abstract

Compliant mechanisms are mechanical devices that transform or transfer motion, force or energy through a single part. These mechanisms have important applications in micro electromechanical systems (MEMS) and other systems that require great accuracy in motion and micro scale. The compliant mechanisms design is performed by Topology Optimization Method, and the optimization problem is formulated to maximize strain-energy stored by mechanism, eliminating the appearance of hinges. The kinematic behavior of the mechanism is imposed through a set of constraints over some displacement degrees of freedom of interest. The elastic behavior of the compliant mechanisms is imposed using a global stress constraint and some important issues associated to stress parametrization are discussed in the realm of mechanism design. The characteristics and the feasibility of this proposal, as well as the influence of parameters related to the formulation, are presented with the aid of some examples.