Fatigue and Collapse of Cyclically Bent Strip of Amorphous Solid

TL;DR

This study investigates fatigue failure in athermal amorphous solids under cyclic bending using atomistic simulations, highlighting accumulated damage as key to predicting failure cycles and developing a scaling theory for failure statistics.

Contribution

It introduces a scaling theory linking accumulated damage to failure cycles in amorphous solids under cyclic loading, based on atomistic simulation data.

Findings

Accumulated damage fluctuates significantly between samples.

Failure cycles depend on the loading amplitude through a scaling relation.

A new theoretical framework predicts fatigue life in amorphous materials.

Abstract

Fatigue caused by cyclic bending of a piece of material, resulting in its mechanical failure, is a phenomenon that had been studied for ages by engineers and physicists alike. In this Letter we study such fatigue in a strip of athermal amorphous solid. On the basis of atomistic simulations we conclude that the crucial quantity to focus on is the {\em accumulated damage}. Although this quantity exhibits large sample-to-sample fluctuations, its dependence on the loading determines the statistics of the number of cycles to failure. Thus we can provide a scaling theory for the W\"ohler plots of mean number of cycles for failure as a function of the loading amplitude.