Experimental and three-dimensional numerical investigation of matrix cracking and delamination interaction with edge effect of curved composite laminates

Abstract

In this paper, the complex failure modes including intra-laminar matrix cracking, inter-laminar delamination and their interaction such as matrix cracking induced delamination and delamination kinking of curved composite laminates with free edge effect are investigated with both experimental testing and three-dimensional numerical modeling. Four-point bending testing of curved composite laminates with designed stacking sequences illustrated the different failure modes, and the experimental results are used to validate the proposed three-dimensional (3D) numerical model with zero-thickness cohesive elements and a mixed-mode traction-separation damage law. It is demonstrated that the proposed 3D modeling can successfully predict the stacking sequence dependent failure modes and locations, as well as crack initiation and propagation sequence, and the failure loads of the curved composite laminates. The advantage of the 3D modeling is further explored and attributed to the ability to predict the complex 3D stress distribution including the free edge effect and the progressive damage accumulation within the critical section of the curved composite laminates.