Estimating Stress Bounds in Early-Stage Design of Distributed Compliant Mechanisms

Synthesis of distributed compliant mechanisms is often a two-stage process involving (a) conceptual topology synthesis, and a subsequent (b) refinement stage to meet stress and manufacturing specifications. The usefulness of a solution is ascertained only after the sequential completion of these two steps, which are in general computationally intensive. This paper presents a strategy to rapidly estimate final operating stresses even before the actual refinement process. This strategy is based on the uniform stress distribution metric, and a functional characterization of the different members that constitute the compliant mechanism topology. It enables selecting the best conceptual solution for further optimization, thus maximally avoiding refinement of topologies that inherently may not meet the stress constraints. Furthermore this strategy enables modifying topologies at the early design stage to meet final stress specifications, thus greatly accelerating the overall synthesis process.