Study on Fracture Mode Transition of Unidirectional CFRP by Using FEM

In the experiments of unidirectional CFRP subjected to tensile load in the fiber direction, the various fracture modes are observed depending on the thickness ratio, the fiber volume fraction and the testing temperature. In case that the values of these factors are low, tensile fracture mode occurs, while their values high, shear fracture mode occurs. In the previous experimental study, the mechanism of this fracture mode transition was discussed. In this study, in order to clarify the mechanism, numerical analyses are conducted using finite element method and the fracture mode transition is simulated. Especially, the attention is paid on the effects of the thickness ratio and the fiber volume fraction on the fracture mode transition. The analyses results well agree with the experimental results and show the validity of the proposed simulation method.