Intralaminar cracking during cyclic loading in laminates with distributed failure stress in 90-plies

Methodology for cracking evolution simulation in 90-plies during cyclic loading is suggested in this paper. It includes using low crack density (where the neighboring cracks do not interact with each other) data from quasistatic and cyclic testing (at one load) to determine parameters in Weibull transverse failure stress distribution generalized for fatigue. Then, Monte Carlo process is used to assign failure stress to elements in the 90-ply. In the model, the failure stress of the element degrades with number of cycles and a crack appears when the failure stress becomes equal to the stress in the element, calculated with computationally efficient analytical method. The model is successfully used to predict cracking in the whole crack density range. In this model, data from cyclic test at one load is sufficient to predict damage at different load. The results suggest that the dependence on stress is slightly underestimated and the shape parameter in fatigue may be higher than in quasi-static tests. Therefore, fatigue tests at least at two load levels are recommended for reliable predictions.