Microdynamics of Chevron-Notched Isotropic Carbon by the Inverse Processing of Elastic Wave

Abstract

The microdynamics of chevron-notched isotropic carbon were investigated by the source inversion processing of elastic waves. The geometric correction factor for stress intensity factor Y^* determined by compliance measurement was found to agree well with that of the superpose method by Munz et al. The fracture toughness of this material was 1.3MPa·m^1/2. The AE monitoring system (ADAS) developed by the authors was demonstrated to measure the surface displacement generated by mode-I cracking. Therefore, the source waves, crack volume and released energy were obtained by the time-domain deconvolution integral of the detected displacement by the theoretical Green's function of the media. The area produced by stable crack propagation was found to be about O.5-1.0mm², and to agree fairly well with the characteristic features of the fracture surface. The stable crack growth velocity was estimated to be about 250m/s.