Prediction of the stiffness degradation in cross-ply laminates due to transverse matrix-cracking: an energy method approach

Abstract This study deals with transverse cracking in cross-ply laminates. A fracture mechanics analysis, using a strain energy based criterion, was used to model the onset of transverse matrix cracking, and the conditions for further damage development. An admissible displacement field, involving unknown functions was assumed, and the principle of minimum potential energy was used to establish these functions. The crack front shape was a part of the assumed displacement field, thus making it possible to minimise the strain energy with respect to the crack opening displacement function. In this paper the aim was to establish a solution to the transverse cracking problem, to use later in a numerical procedure for the viscoelastic damage predictions for a cross-ply laminate. The model accounts for residual stresses. A number of finite element solutions were performed to verify the accuracy of the presented analytical solution. Predictions of stiffness degradation due to matrix cracking, and matrix cracking as a function of applied stress are presented. Keywords: Damage mechanicstransverse crackingenergy methodsstiffness degradationcross-ply compositesresidual stresses