A Metric to Evaluate and Synthesize Distributed Compliant Mechanisms

Abstract

Compliant mechanisms with evenly distributed stresses have better loadbearing ability and larger range of motion than mechanisms with compliance and stresses lumped at flexural hinges. In this paper, we present a metric to quantify how uniformly the strain energy of deformation and thus the stresses are distributed throughout the mechanism topology. The resulting metric is used to optimize crosssections of conceptual compliant topologies leading to designs with maximal stress distribution. This optimization framework is demonstrated for both singleport mechanisms and singleinput singleoutput mechanisms. It is observed that the optimized designs have lower stresses than their nonoptimized counterparts, which implies an ability for singleport mechanisms to store larger strain energy, and singleinput singleoutput mechanisms to perform larger output work before failure.