Prediction of low-velocity impact behavior of multi-dircetional CFRP laminates based on micro-mechanics failure theory

We deal with analysis and prediction of the failure mechanism and the damage procedure of the multi-directional carbon fiber reinforced plastics (CFRP) laminates under the condition of low velocity impact with small energy based on the micro-mechanics of failure (MMF) theory. The impact damage behavior analysis method for the laminated structure was established based on MMF theory. During the process of impact loading, the constituent failure categories can be identified first by the MMF theory, then the comesponding material properties degradation scheme was applied to analyze the progressive failure of composites based on the constituent failure categories. Developed the user-defined material subroutine based on explicit analysis (VUMAT ) on the ABAQUS, it is a impact damage analysis program of laminate based on MMF theory. Finally, under the condition of low velocity impact with small energy, the failure mechanism and damage appearance of the multi-directional CFRP laminates was predicted based on impact damage behavior analysis method of MMF theory. The failure mechanisms and damage appearance obtained from both predicted results and test were compared, then the accuracy of the impact damage prediction method based on MMF theory were analyzed. The results show that the error between predicted pit diameter and test pit diameter is 4.8%,the predicted failure mechanism and damage appearance are consistent with the actual analysis.