Low velocity impact on the structural free edge would threaten the safety of laminated composite structures. In this paper, experimental and numerical investigations were conducted to study the edge-on impact behaviors of T700/YPH307 composite laminates. Visual inspection, ultrasonic C-scanning, electron microscopy and X-ray computed tomography (CT) technique were performed to detect the post-impact damage status of composite laminates subjected to edge-on impact, which could further reveal 3D spatial distribution of internal damage. Based on the Mohr’s theory of fracture plane, a continuum damage mechanics model, considering fracture plane angle within anisotropic materials, was established. And with combination of cohesive zone model, the initiation, propagation and interaction of complicated edge-on impact damage modes, i.e. intra-laminar fiber and matrix failure and inter-laminar delamination, could be characterized in detail. There is a good agreement between numerical and experimental results. It is suggested that failure mechanisms induced by edge-on impact mainly include two distinct characteristics, namely the generation of localized debris wedge beneath the impactor corresponding to peak value of impact force, and the bending fracture of outer plies due to the wedge effect at the stage of stable fluctuations in impact force. Furthermore, it is found that the internal damage would be more serious with the impact energy increasing, while stacking sequence has a relatively small influence on the edge-on impact responses and damage morphology.
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