Dynamic behavior of elastic strips near shape transition

TL;DR

This paper introduces a new method to analyze the dynamic behavior of elastic strips near shape transitions, extending bifurcation analysis to all transition types and providing insights into their physical mechanisms.

Contribution

It develops a straightforward approach to extend asymptotic analysis of nonlinear snap-through to other shape transitions in elastic strips.

Findings

Normal forms of all three bifurcation types obtained

Method allows prediction of dynamic responses near transitions

Provides tools for diagnosing and anticipating shape transitions

Abstract

Elastic strips provide a canonical system for studying the mechanisms governing elastic shape transitions. Buckling, linear snap-through, and nonlinear snap-through have been observed in boundary-actuated strips and linked to the type of bifurcation the strip undergoes at the transition. For nonlinear snap-through, previous work obtained the normal form at the bifurcation. However, to date, there is no methodology for extending this analysis to other types of transition. Here, we study a set of three systems where a buckled elastic strip is actuated through rotation of its boundaries. Depending on the direction of rotation, the system exhibits all three types of shape transitions. We introduce a simple method to analyse the dynamic characteristics of an elastic structure near a transition. This method allows us to extend, in a straightforward manner, the asymptotic analysis proposed for nonlinear snap-through to the two other types of transition. We obtain the normal forms of these bifurcations, and show how they dictate all the dynamic characteristics of the elastic strip. This analysis provides a profound understanding of the physical mechanisms governing elastic shape transitions and reliable tools to diagnose and anticipate these transitions.