Translaminar-envelope ply for CFRP mechanical enhancement

Pursuing the trend of ply-level innovation in the field of high-performance CFRP composites, a pseudo-woven layup configuration has been developed by interlacing a thin-ply prepreg in the translaminar-envelope manner space-orthogonally inside a homogenized 4-ply sub-laminate to acquire mechanical superiorities for the global multidirectional laminate. This evolved layup structure possesses the stiffening feedbacks on in-plane principal properties by the locally-regulated 0 degrees ply amount, and exerts the multi-interface synergy on sheardriven interlaminar fractures by the long-acting binding action. Further, the high robustness of structural performances has been revealed by resistance and tolerance against severe low-velocity impact damage, achieving up to 60 % decrease in the projected delamination area and over 60 % increase in the post-impact compressive strength. The translaminar-envelope layup configuration is expected to enhance the service capability of CFRP laminates.