Multi-scale Modeling Approach to Acoustic Emission during Plastic Deformation

TL;DR

This paper presents a multi-scale modeling framework to understand the origin of acoustic emissions during plastic deformation, linking dislocation dynamics with elastic responses, and explaining observed acoustic signals during the Portevin-Le Chatelier effect.

Contribution

It introduces a novel multi-scale approach combining dislocation dynamics and elastic degrees of freedom to explain acoustic emission phenomena during plastic deformation.

Findings

Acoustic emission bursts are well separated during type C serrations.

Bursts merge into continuous signals during propagating type A bands.

The model successfully explains different acoustic emission patterns observed experimentally.

Abstract

We address the long standing problem of the origin of acoustic emission commonly observed during plastic deformation. We propose a frame-work to deal with the widely separated time scales of collective dislocation dynamics and elastic degrees of freedom to explain the nature of acoustic emission observed during the Portevin-Le Chatelier effect. The Ananthakrishna model is used as it explains most generic features of the phenomenon. Our results show that while acoustic emission bursts correlated with stress drops are well separated for the type C serrations, these bursts merge to form nearly continuous acoustic signals with overriding bursts for the propagating type A bands.