Combining acoustic emission and digital image correlation analysis for dynamic damage response of woven spacer structure reinforced sandwich composites

This study reveals the dynamic damage process and the bending response of woven spacer structure reinforced sandwich composites (WSRS) by combining the acoustic emission (AE) technique and the digital image correlation (DIC) method. The typical load-displacement curve of six WSRSs was divided into elastic deformation, damage developing, and rapid damage stages. According to AE, the primary failure modes of WSRS were foam failure, interface delamination and core-pile separation, and surface matrix cracking. The failure behavior of the specimens was identified. It revealed that when subjected to bending stress, the load-bearing capacity of WSRS in the weft direction was higher than in the warp direction. While the failure areas were extended, indicating that the core-pile structure played a dominant role. The stress was mainly concentrated in the core layer, increasing the failure degree and damage rate, while the strain nephogram showed superior integrity. Consequently, the weft direction of WSRS exhibited better integrity and load-bearing capacity.