Theory and analysis of deformation moment tensor due to microcracking

✍ Scribed by M. Enoki; T. Kishi

• Book ID: 104615533
• Publisher: Springer Netherlands
• Year: 1988
• Tongue: English
• Weight: 942 KB
• Volume: 38
• Category: Article
• ISSN: 1573-2673
• DOI: 10.1007/bf00019805

✦ Synopsis

The method to represent a general infinitesimal deformation as a deformation moment tensor is proposed and the physical meaning of deformation moment tensor in the case of microcracking is made clear. Developing the measuring and analysis system for acoustic emission waveform analysis, these moment tensor components due to microcracking can he determined experimentally. The remarkable method in this study is established to evaluate the moment tensor with the dynamic Green's function of finite media by computer simulation due to finite difference method and the iterative deconvolution with multiple Green's function.

Applying the present method to fracture toughness testing for ASTM A470 steel, moment tensor of quasicleavage facet within the plastic zone near the tip of the pre-crack was obtained from the six channels' acoustic emission waveform analysis. In addition to three-dimensional location of these microcracks, fracture mode and quantitative size of microcracks can be estimated from the obtained moment tensor.