Computational synthesis of large deformation compliant mechanisms undergoing self and mutual contact

TL;DR

This paper presents a continuum synthesis approach for designing large deformation contact-aided compliant mechanisms with self and mutual contact, capable of complex path generation with multiple contact interactions.

Contribution

It introduces a novel topology optimization method using honeycomb tessellation and boundary smoothing to design CCMs with complex contact behaviors and path generation capabilities.

Findings

Successfully designed CCMs with multiple contact interactions.

Demonstrated path generation with multiple kinks.

Validated the approach with finite element analysis.

Abstract

Topologies of large deformation Contact-aided Compliant Mechanisms (CCMs), with self and mutual contact, exemplified via path generation applications, are designed using the continuum synthesis approach. Design domains are parameterized using honeycomb tessellation. Assignment of material to each cell, and generation of rigid contact surfaces, are accomplished via suitably sizing and positioning negative circular masks. To facilitate contact analysis, boundary smoothing is implemented. Mean value coordinates are employed to compute shape functions, as many regular hexagonal cells get degenerated into irregular, concave polygons as a consequence of boundary smoothing. Both, geometric and material nonlinearities are considered in the finite element analysis. The augmented Lagrange multiplier method in association with an active set strategy is employed to incorporate both self and mutual contact. CCMs are evolved using the stochastic hill climber search. Synthesized contact-aided compliant continua trace paths with single and importantly, multiple kinks and experience multiple contact interactions pertaining to both self and mutual contact modes.