Using Acoustic Emission and Video Recording for Monitoring the Kinetics of Damage under Compression of Composite Samples

The results of studying the fracture of a batch of fiber-reinforced polymer (FRP) samples under compression have been considered. The kinetics of damage and fracture of structural bonds in a FRP package under the impact of compressive load was studied using acoustic emission (AE) in combination with video recording. Correlations between fractures of the FRP package occurring on the micro-, meso-, and macroscopic levels and the simultaneously registered location pulses, i.e., their energy parameters, shape, and spectrum, were established. New criterial parameters including the activity of registration of the location pulses in the energy clusters and their weight content were analyzed. The structural-phenomenological approach implemented by dividing the entire array of the AE data into energy clusters made it possible to control the degree of fracture of the material using the activity of registration and the weight content of the location pulses in clusters of the lower, middle and upper energy levels. Comparison of AE events recorded at the stages of loading of the tested samples with video footage of the fracture of structural bonds in the FRP package made it possible to establish the relation between the occurring damage and the recorded AE pulses, their parameters, shape, and spectrum.