Nonlinear geometric effects in mechanical bistable morphing structures

TL;DR

This paper investigates how nonlinear geometric effects influence bistability in shell structures, providing a theoretical framework and experiments to classify conditions for bistability based on key parameters.

Contribution

It introduces a classification of bistability conditions in shells by identifying two dimensionless parameters that control large deformation behavior.

Findings

Two dimensionless parameters govern bistability.

Extended large deformation theory of shells.

Experimental validation of theoretical predictions.

Abstract

Bistable structures associated with non-linear deformation behavior, exemplified by the Venus flytrap and slap bracelet, can switch between different functional shapes upon actuation. Despite numerous efforts in modeling such large deformation behavior of shells, the roles of mechanical and nonlinear geometric effects on bistability remain elusive. We demonstrate, through both theoretical analysis and table-top experiments, that two dimensionless parameters control bistability. Our work classifies the conditions for bistability, and extends the large deformation theory of plates and shells.