ACOUSTIC EMISSION MONITORING OF DAMAGE EVOLUTION DURING FATIGUE OF METAL-MATRIX COMPOSITES

摘要

The acoustic emission (AE) technique was employed for in-situ monitoring of damage evolution in metal matrix composites under fully reversed tension-compression loading at constant total strain amplitude. A strong correlation is obtained between AE and mechanical parameters characterizing fatigue damage of MMCs. The AE spectral analysis and unsupervised clustering are used for identification of active AE sources. A dominant role of particle breakage is demonstrated. Three stages of fatigue failure are observed and characterized by different rates of damage accumulation. It is demonstrated that the onset of final macroscopic crack initiation and propagation can be reliably detected by means of AE well before failure.