Fatigue life prediction of hybrid carbon-flax-epoxy laminates using progressive failure analysis and cohesive zone model

A 3D progressive fatigue damage model was incorporated into ABAQUS software to predict the fatigue life of hybrid carbon-flax-epoxy composites. A cohesive zone method was employed to simulate delamination damage at carbon/flax interface. To evaluate the accuracy of the finite element model, two different layups, namely, unidirectional [0–90_C2/0 _F6]_S (UD) and angle-ply [0–90_C2/(±45) _F6]_S (AP), consisting of 12 flax fibers layers (F) sandwiched between four woven carbon fibers layers (C) were created using hand lay-up technique and then placed in compression molding. There is a good agreement between experimental and predicted fatigue life. It was observed that the predicted fatigue life is reduced by about 14% by changing the void content from 0.38% to 3.83%. The finite element analysis revealed that the matrix in the flax region of the AP layup failed at 12% of fatigue life, followed by delamination at the carbon/flax interface, consistent with SEM results.