Tailoring high precision polynomial architected material constitutive responses via inverse design

TL;DR

This paper introduces a topology optimization method to design structures with precise, customizable polynomial nonlinear responses, advancing the creation of materials and systems with tailored nonlinear behaviors for diverse applications.

Contribution

It presents a novel inverse design approach that decouples nonlinear response from stiffness, enabling high-precision design of complex polynomial behaviors in structures.

Findings

Successfully designed structures with various polynomial nonlinear behaviors

Achieved high accuracy in matching desired nonlinear responses

Enabled new possibilities for nonlinear metamaterials and impact mitigation

Abstract

The design of specified nonlinear mechanical responses into a structure or material is a highly sought after capability, which would have a significant impact in areas such as wave tailoring in metamaterials, impact mitigation, soft robotics, and biomedicine. Here, we present a topology optimization approach to design structures for desired polynomial nonlinear behavior, wherein we formulate the problem in such a way as to decouple the nonlinear response from the stiffness. We show results across qualitatively different polynomial behaviors while achieving a high degree of precision, creating a path toward analytically tractable nonlinear dynamical systems. The approach enables access to previously difficult to design for, or hitherto unachieved, nonlinear behavior via optimized structures, which can furthermore be incorporated as unit cells of designer materials with tailored nonlinear properties.