Beyond von Mises Truss Models: Emergent Bistability in Mechanical Metamaterials

TL;DR

This paper investigates emergent bistability in hyper-elastic mechanical metamaterials, showing that cooperative effects lead to bistability beyond traditional models, supported by experiments, simulations, and a new analytical model.

Contribution

It introduces a novel analytical model explaining emergent bistability in metamaterials, surpassing the limitations of von Mises truss models.

Findings

Single units are unistable.

Combining units results in bistability.

The new model accurately predicts emergent behavior.

Abstract

We observe and analyze the phenomenon of bistability emergent from cooperative stiffening in hyper-elastic metamaterials. Using experimental and numerical results of identical geometric designs, we show evidence that a single unit is unistable while combining two units can result in bistability. Our study demonstrates that the von Mises truss model cannot describe such emergent behavior. Hence, we construct a novel and simple analytical model to explain this phenomenon.