Conditional stability in metamaterials: Experiments, modeling, and 3D design

Abstract

The mechanical properties of metamaterials are typically governed by their architecture in the undeformed configuration, which limits their adaptability. Recent work has shown that interactions between structural components with strongly nonlinear responses can reshape the system’s energy landscape. For instance, a structure composed of four von Mises trusses coupled through an elastic matrix exhibits conditional stability: stability along one principal direction can be tuned on demand by modifying the metamaterial’s topological state along the orthogonal direction. Here, we systematically investigate the mechanical response of such conditionally stable structures through a combination of experiments, Finite Element simulations, and analytical modeling. Building on these insights, we propose a strategy to extend conditional stability to a three-dimensional architecture, demonstrating its potential for reprogrammable energy absorption.