Investigation on damage evolution of open-hole plain woven composites under tensile load by acoustic emission signal analysis

The open-hole structure has been concerned in the design of composite components, which inevitably brings about local damage and stress concentration with a substantial reduction in structural stability and strength of the resulting composites. In this paper, damage mode identification, damage initiation detection, and damage evolution analysis of open-hole plain woven composites (OHPWCs) under tensile load were investigated by acoustic emission (AE) signal analysis. The effect of the open-hole diameter on mechanical properties and failure mechanisms was assessed. The peak frequency ranges of typical failure modes were identified by k-means++ cluster analysis: matrix cracking [0–160 kHz], fiber/matrix debonding [160–220 kHz], fiber pull-out [220–300 kHz], and fiber breakage [300–450 kHz], respectively. Moreover, a novel concept of damage participation rate (DPR) was proposed based on AE count to characterize the contribution of different damage modes to the overall failure of the plain woven composites. The results showed that matrix cracking was the major proportion of damage modes in the damage evolution process of OHPWCs under tensile load and the DPR of the fiber breakage increases with the increase in the diameter of the OHPWCs.