Monte-Carlo simulation of multiple fracture in the transverse ply of cross-ply graphite-epoxy laminates

Abstract

Graphite-epoxy cross-ply laminates generally show multiple fracture of the transverse ply at higher applied stress. This phenomenon is described by means of a Monte Carlo simulation method based on the assumption that the strength of the transverse ply obeys a twoparameter Weibull distribution function. The main results show that the smaller the scatter of strength of the 90~ (i.e. the larger the shape parameter at a constant mean strength of the Weibull distribution), the higher becomes the threshold for the multiple fracture to occur, and the more rapidly the length of 90~ segments decreases with increasing applied stress once multiple fracture takes place. The methods to determine the shape and scale parameters of the Weibull distribution for the strength of the 90~proposed by Manders et al. and Peters are proved to be useful even for a small number of test specimens. When the interfacial bond strength between 0 ~ and 90~ is low, saturation of 90~ cracking occurs at higher applied stress. The stress-carrying capacity and stiffness of the composites as a whole are reduced by multiple fracture of the 90~ This reduction is more pronounced at increasing applied stress or at a larger number of transverse cracks, especially when the interfacial bond strength is low.