Acoustic Emission of Growing Microcracks in Vibration-Loaded Material

TL;DR

This paper presents a theoretical model explaining how growing microcracks under cyclic load produce anisotropic acoustic emissions influenced by dislocation dynamics and diffusion processes.

Contribution

It introduces a novel mechanism linking microcrack growth, dislocation creep, and acoustic emission anisotropy in vibrating materials.

Findings

Acoustic emission direction depends on microcrack length and dislocation dynamics.

The model accounts for diffusion processes in the Kottrell zone.

Acoustic emission is anisotropic and varies with microcrack growth.

Abstract

We propose mechanism describing an acoustic emission by growing microcracks in the material under external cycled load. We use the theoretical approach based on Huygens principle for elastic solid con-tinuum with an account for dislocation creep in the zone of abrasive action. We show that the acoustic emission is anisotropic and its main direction depends not only on the effective length of microcrack but also on dynamics of dislocation structure and on diffusion processes in Kottrell zone which give rise to microcracks.