Acoustic emission waveform analysis in two-dimensional models
Shigeishi Mitsuhiro; Ohtsu Masayasu
Abstract:Acoustic emission (AE) is a phenomenon caused by the propagation of elastic wave generated from micro cracks as sources. A procedure named as SiGMA (simplified Green's function for moment tensor analysis) to identify the crack kinematics from AE waveforms has been developed recently. By this procedure, the crack location, crack orientation and crack type can be determined. To apply the SiGMA procedure for AE source inversion in two-dimensional (2D) models, the SiGMA-2D procedure is proposed in this paper. The in-plane uniaxial compression tests of poly-methyl-methacrylate plates having an internal through-thickness slit are carried out for the experimental verification of SiGMA-2D solutions. These results confirm the applicability of the SiGMA-2D procedure for elucidating the crack mechanism. Crack identification by using SiGMA-2D is also performed in the mixed-mode fracturing of concrete and mortar plates, and the fracture process is investigated. Key Words:acoustic emission, elastic wave, waveform analysis, micro crack inversion, moment tensor, crack prpagation, fracture mechanics