A simple microscopic model for the dynamics of adhesive failure

TL;DR

This paper presents a microscopic model explaining the bi-modal stress-strain behavior observed in soft adhesives under tension, highlighting the effects of bond length and loading conditions, aligning with experimental findings.

Contribution

It introduces a simple microscopic model for adhesive failure that accounts for bi-modal stress-strain curves and characterizes conditions leading to such behavior.

Findings

Bi-modal stress-strain curves can occur due to finite bond length effects.

Loading velocity influences the occurrence of bi-modal behavior.

Model aligns qualitatively with experiments on unconfined adhesives.

Abstract

We consider a microscopic model for the failure of soft adhesives in tension based on ideas of bond rupture under dynamic loading. Focusing on adhesive failure under loading at constant velocity, we demonstrate that bi-modal curves of stress against strain may occur due to effects of finite polymer chain or bond length and characterise the loading conditions under which such bi-modal behaviour is observed. The results of this analysis are in qualitative agreement with experiments performed on unconfined adhesives in which failure does not occur by cavitation.