Acoustic Response and Micro-Damage Mechanism of Fiber Composite Materials under Mode-II Delamination

Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission (AE) statistical analysis towards fiber composites under mode-II delamination damage. The load curve, AE relative energy, amplitude distribution, and amplitude spectrum are obtained and the delamination damage mechanism of the composites is investigated by the microscopic observation of a fractured specimen. The results show that the micro-damage accumulation around the crack tip region has a great effect on the evolutionary process of delamination. AE characteristics and amplitude spectrum represent the damage and the physical mechanism originating from the hierarchical microstructure. Our finding provides a novel and feasible strategy to simultaneously evaluate the dynamic response and micro-damage mechanism for fiber composites.