塑性変形に起因したアコースティック・エミッションの分子動力学解析

抄録

Acoustic emission (AE) is the elastic wave phenomenon due to the energy release by fracture in materials, then AE is widely used for one of nondestructive inspection techniques. Because dislocation motion in crystalline materials also release the elastic energy, AE can be observed during plastic deformation in crystalline materials. In general, dislocations construct a stable structure to reduce their self-energies and the dislocation structure strongly determine the strength of the materials. Therefore, there is a possibility that the information of AE contains the information of dislocation structure and the strength of the materials. In order to investigate the relationship among AE caused by plastic deformation, dislocation structure, and material strength, we perform the molecular dynamics simulations of the collapse of dislocation structures under shear deformation. It is confirmed that the influence of dislocation structure on the strength observed in MD simulations well corresponds to the dislocation theory and the relationship between material strength and AE caused by plastic deformation take a positive correlation. Hence, it is found that the information of AE possibly contains the information of dislocation structures and the strength.