Collapse characterization and shock mitigation by elastomeric metastructures

Abstract

Viscoelastic metastructures made with elastomeric polymers are recently suggested as solutions for shock mitigation and crash absorption. In these investigations, the mechanical properties are used as proxy indicators of capabilities to suppress energy transfer under such dynamic load conditions. Yet, recent high speed video studies revealed a startling disconnect between quasi-static and dynamic behavior in metastructures having internal beam networks due to the coupled local–global dynamics that are not triggered during quasi-static load cycles. This research undertakes an extensive high speed video data collection synchronized with force measurements to reveal the influences that govern transient shock mitigation properties in elastomeric metastructures. Despite an intuitive advantage of prolonging the collapse behavior through material design, it is conclusively found that unimodal collapse of the metastructure cross-section is the most effective mechanism to mitigate shock amplitude, prolong the duration of the transmitted force, and to reduce the impulse passed through the media. This research may specifically inspire the next generation of elastomeric, reusable shock damping materials.