Residual crashworthiness of braided composite tube with transverse multi-impact damages: Experimental and numerical study.

• The delamination damage distribution induced by multi-impact was identified. • The sensitivity of axial compression performance to impact damage was studied. • Proposed FE model provided accurate predication for CAI scenario of braided tube. In this study, damage behaviors and residual crashworthiness characteristics of braided composite tube with transverse pre-impact damages subjected to axial compression were investigated by experimental and numerical methods. The compression tests were conducted on intact, single impact and repeated impact tubes at identical, adjacent and opposite positions to analyze the effects of impact damages. A multi-step finite element model considering the progressive damage characteristics was developed in ABAQUS/Explicit to predict the failure behaviors of braided tube. It was found that the damage behavior and residual performance of braided tube subjected to axial compression were dominated by impact induced delamination distribution with respect to area and position. A relatively small delamination area induced by single impact resulted in similar progressive folding damage mode and energy absorption capacity as in intact tube. For repeated impact, delamination with increased area at identical position leaded to local buckling damage mode, while small delamination areas distributed at adjacent and opposite positions caused U-shape and W-shape fracturing damage modes, respectively. Consequently, the transformation of damage mode resulted in significantly reduced residual crashworthiness characteristics in repeated impact tubes compared to intact and single impact tubes. [ABSTRACT FROM AUTHOR]