Effect of interface properties on micromechanical damage behavior of fiber reinforced composites

Abstract

This paper investigates the micromechanical damage behavior of carbon-epoxy composite on the transverse tensile of representative volume elements (RVEs) with various fiber volume fractions. A new algorithm is developed to generate the random distribution of fibers in the RVE, and it is possible to create fiber distributions with high fiber volume fractions. The fibers and matrix are considered linear elastic and elastoplastic with progressive damage criterion, respectively. Fiber-matrix debonding and matrix crack are considered as the dominant damage modes. The normal cohesive properties distribution is applied for interfaces between fibers and the matrix in order to achieve a more realistic microstructure. To investigate the effect of the position of fibers with the weakest cohesive strengths, sensitivity analyses concerning the different arrangements of specific normal cohesive properties on the RVE’s strength are performed. Moreover, the effects of different damage parameters, such as random fiber distributions and various cohesive parameters on the overall damage behavior of the RVE, are described in detail. It is revealed that the application of a normal cohesive distribution sharply reduces the maximum strength of the RVE and shifts the strain of damage initiation point and crack propagation path.