Snap-through time of arches is controlled by slenderness and imperfections

TL;DR

This study investigates how the dynamics of snap-through in elastic arches are influenced by slenderness and imperfections, revealing that imperfections significantly affect the duration and mode of snap-through.

Contribution

It provides the first detailed analysis of snap-through dynamics in curved structures, linking imperfections and slenderness to the speed and mode of snap-through behavior.

Findings

Snap-through dynamics slow with increased slenderness.

Imperfections reduce snap-through time dramatically.

Analytical expressions for snap-through times are derived.

Abstract

Snap-through occurs in elastic structures when a stable equilibrium configuration becomes unstable, resulting in rapid motion towards a new and distinct stable state. While static analyses of snap-through are well documented, the dynamics of snap-through remain under-explored, particularly in structures with natural curvature. Using a combination of finite element simulations and multiple-scales analysis, we show that the snap-through dynamics of an arch under a central point load are controlled by its slenderness and imperfections embedded in the system. As the slenderness increases, the snap-through dynamics slow down, and the mode of snap-through changes from limit-point buckling to bifurcation buckling. When bifurcation buckling occurs, snap-through is preceded by an extended period of oscillatory behaviour. The duration of these pre-snap-through oscillations, and hence the snap-through time, is entirely controlled by imperfections in the system. Increasing the strength of imperfections dramatically reduces the snap-through time. Analytical expressions for the snap-through times are presented for limit point and bifurcation buckling. Our work suggests that natural curvature and deliberately introduced imperfections can be used to tune the snap-through dynamics of new functional materials.