Reliability analysis of the delamination onset and growth due to the matrix cracking in general composite laminates

Unlike other materials, composite laminates have more uncertainty sources, such as uncertainty in the material properties; hence it is very essential to predict the probability of the occurrence of various types of damage modes in composite laminates due to random behaviors of composite structures. Matrix cracking induced delamination (MCID) is one of the catastrophic modes that can occur in composite laminates. In this paper, a new algorithm for probabilistic prediction of MCID based on the concept of energy release rate and its critical value was developed and by applying this proposed framework, the reliability analysis of MCID damage was performed. The limit state function was formulated using a general failure criterion which was developed by the authors of this article, previously. To represent the performance of the proposed algorithm, the probability of the occurrence and growth of MCID in a quasi-isotropic laminate including 45°, 90°, -45° and 0° plies under different loading conditions and various stacking sequences was extracted by using first and second order reliability methods (FORM and SORM),. The verification of the obtained probabilities was performed using Monte Carlo simulation (MCS). In addition, some significant results were validated using several experimental data, qualitatively. The effect of variables such as the ply thickness, the level of longitudinal uniaxial stress and the presence of general in-plane stresses on the probability of occurrence and growth of MCID was investigated.