Moment tensor inversion of acoustic emission waveforms for source characterization
- Kumamoto Univ. (Japan)
Acoustic emission (AE) waveforms result theoretically from elastic waves nucleated due to microcracking. Thus, AE waveforms could be synthesized from the elastodynamic theory. It leads to an inverse problem of AE waveforms for the source characterization. Mathematically AE sources are characterized with respect to kinetics and kinematics. It is already known that crack kinetics could be determined as a source function by the deconvolution analysis, while it is recently realized that crack kinematics are formulated by the moment tensor representation. An inverse problem for the determination of moment tensor components from AE waveforms is investigated and a SIGMA procedure is developed to determine crack kinematics in experiments. The procedure is based on simplified Green`s functions for moment tensor analysis, which could determine the moment tensor components from the first motion of AE waveforms and classify AE sources into tensile cracks, shear cracks, and mixed-mode cracks. For the classification, the eigenvalue analysis and its decomposition of the moment tensor are performed. Then, crack orientations are determined from the directions of eigenvectors. Theoretical treatment is applied to the observation of the fracture process nucleation around the notch tip in concrete specimens. Results demonstrate the fracture mechanisms of disordered materials around pre-existing cracks.
- OSTI ID:
- 175341
- Report Number(s):
- CONF-950686-; TRN: 95:006111-0299
- Resource Relation:
- Conference: Joint applied mechanics and materials summer meeting, Los Angeles, CA (United States), 28-30 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of AMD - MD `95: Summer conference; PB: 520 p.
- Country of Publication:
- United States
- Language:
- English
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