Using of acoustic emission and video recording for monitoring the kinetics of damage upon compression of composite specimens

Abstract

The results of studying fracture of a batch of fiber-reinforced polymer (FRP) specimens upon compression are considered. The kinetics of damage and fracture of structural bonds in the FRP package under the impact of compressive load has been studied using acoustic emission (AE) in combination with video recording. Correlations between fractures occurring on the micro-, meso-, and macroscopic levels of the FRP package and the AE events registered at the same time, i.e., their energy parameters, shape, and spectrum were determined. New criterion parameters including the activity of registration of AE events in energy clusters and their weight content were analyzed. The structural-phenomenological approach, implemented by dividing the entire array of acoustic emission data into energy clusters provided the possibility of control of the kinetics of the material fracture using the registration activity and the weight content of AE events in clusters of the lower, middle and upper energy levels. Comparison of the AE events recorded at the stages of loading of the tested specimens with video footage of the fracture of structural bonds in the FRP package made it possible to set up a correspondence between the occurring damage and the recorded AE signals, their parameters, shape and spectrum.