On topology optimization of large deformation contact-aided shape morphing compliant mechanisms

TL;DR

This paper introduces a topology optimization method for designing large deformation contact-aided shape morphing compliant mechanisms, incorporating nonlinearities, contact modeling, and a novel mask-based design approach.

Contribution

It presents a new topology optimization framework using circular masks and a hill-climbing optimizer for large deformation contact-aided mechanisms.

Findings

Successfully designed four shape morphing mechanisms with desired profiles

Validated designs using commercial software simulations

Studied the impact of frictional contact surfaces on profiles

Abstract

A topology optimization approach for designing large deformation contact-aided shape morphing compliant mechanisms is presented. Such mechanisms can be used in varying operating conditions. Design domains are described by regular hexagonal elements. Negative circular masks are employed to perform dual task, i.e., to decide material states of each element and also, to generate rigid contact surfaces. Each mask is characterized by five design variables, which are mutated by a zero-order based hill-climbing optimizer. Geometric and material nonlinearities are considered. Continuity in normals to boundaries of the candidate designs is ensured using a boundary resolution and smoothing scheme. Nonlinear mechanical equilibrium equations are solved using the Newton-Raphson method. An updated Lagrange approach in association with segment-to-segment contact method is employed for the contact formulation. Both mutual and self contact modes are permitted. Efficacy of the approach is demonstrated by designing four contact-aided shape morphing compliant mechanisms for different desired curves. Performance of the deformed profiles is verified using a commercial software. The effect of frictional contact surface on the actual profile is also studied