Modelling the kinetics of transverse cracking in composite laminates

A micromechanical model of transverse cracking in composite laminates under monotonic loading is proposed. To compute stresses, we simplify the problem and use a uniaxial model, often called a shear-lag analysis, which allows an analytical determination of the stress fields. In the model the laminate is discretised into cells including potential cracks. The initial strengths of these cells are randomly distributed according to a law which is experimentally identified from a series of tests on unidirectional samples taking into account the size effects. Then, by using a single series of tests, we can simulate the transverse cracking of 90° plies in any kind of laminate. The predictions of the simulations are validated on [0₂,90₂]_s carbon/epoxy composite specimens. We have observed and counted cracks during experimental tension tests and compared them with simulations. We observe good agreement between predictions of the model and experimental results.