Compression failure mechanisms of 3-D angle interlock woven composites subjected to low-energy impact

Instrumented drop weight impact and compression-after-impact tests (CAI) were conducted to assess the impact performance, compression failure mechanisms and residual compression strength of three-dimensional (3-D) interlock carbon woven/epoxy composites. Comparative evaluations were also contrasted with those for Conventional two-dimensional (2-D) plain woven/epoxy laminated composites. The results show that the 3-D interlock woven composites exhibited a smaller impact damage area and higher % residual strength than the 2-D woven laminated composites. The improvements were attributed to the larger crimp-angle and interlacing structure of the 3-D interlock woven composites, which inhibits delaminated propagation along the plane direction. Besides, the fact that the 3-D interlock woven structure prevents buckling of the fibre tows under compressive load also contributes to the CIA performance.