Study of the Fracture Kinetics of a Unidirectional Laminate Using Acoustic Emission and Video Recording

Abstract

The kinetics of fracture of structural bonds in a unidirectional laminate package under the effect of tensile load is studied using acoustic emission (AE) combined with video recording. A correspondence between the fractures occurring at micro-, meso-, and macroscale levels of the laminate package and the location pulses thus recorded and their energy parameters, shape, and spectrum is determined. Data on testing of the new criterion parameters used in acoustic emission monitoring, including the frequency of registration of location pulses in energy clusters and their weight content, as well as the methods providing separation of location pulses into the clusters with similar spectra related to the same or similar types of acoustic emission events, are presented. The proposed parameters and structural-phenomenological approach implemented through dividing the entire array of acoustic-emission data into energy clusters make it possible to quantify the degree of destruction of structural bonds of structural material at all scale levels and predict the residual strength of the product. Fusion of the acoustic emission events recorded at different stages of specimen loading and images of video recording of damage accumulation and fracture of the structural bonds in a unidirectional laminate package revealed the correspondence between the fracture of the composite occurring at micro-, meso-, and macroscale levels, acoustic waves thus generated and location pulses, and their energy parameters, shape, and spectrum.