Geometric Modeling and Optimization of Multi-Material Compliant Mechanisms Using Multi-Layer Wide Curves

Multi-material compliant mechanisms enhance the performance of regular single-material compliant mechanisms by adding a new design option, material type variation. This paper introduces a geometric modeling method for multimaterial compliant mechanisms by using multi-layer wide curves. Based on the introduced modeling method, a geometric optimization approach for multi-material compliant mechanisms is proposed. A multi-layer wide curve is a curve with variable cross-sections and multiple materials. In this paper, every connection in the multi-material compliant mechanism is represented by a multi-layer wide curve and the whole mechanism is modeled as a set of connected multi-layer wide curves. The geometric modeling and optimization of a multi-material compliant mechanism are considered as the generation and optimal selection of the control parameters of the corresponding multi-layer wide curves. The deformation and performance of multi-material compliant mechanisms is evaluated by the isoparametric degenerate-continuum nonlinear finite element procedure. The problem-dependent objectives are optimized and the practical constraints are imposed during the optimization process. The effectiveness of the proposed geometric modeling and optimization procedures is verified by the demonstrated examples.