Abstract
Damage monitoring of impacted materials by Acoustic Emission (AE) is useful for integrity evaluation. The monitoring is, however, generally difficult due to overlapping of AE signals by impact and damage. The autors proposed a new method to monitor crack generation by extracting the fracture-induced AE signals from strong AE signals produced by impact. Here, AE sensors were mounted on two end faces to minimize the effect of impact -induced AE. The impact testing was conducted for a 5mm-thick PMMA plate. Crack initiation was successfully monitored by the proposed method. Crack kinetics (opening speed and volume) was estimated by waveform simulation of the S0-Lamb packet using experimental overall transfer function of the system. The impact force history was also estimated using impact induced AE detected by a sensor on the impact surface.
