A Farrokhabadi - Assistant Professor, Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
M Bahrami - M.Sc. Student, Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran

The present research investigates the effects of matrix cracking formation on the bending stiffness reductionof cross-ply composite laminates by using an analytical model based on cracking density. For this purpose, therelationships of stiffness reduction for one damaged lamina are used and the changes in mechanical properties of crossplylaminates in the presence of matrix cracking are calculated. A cross-ply laminate made of carbon/epoxy has beeninvestigated and the results are compared with available numerical results. Then, strain energy release rate in presenceof matrix cracking is calculated by utilization of linear elasticity relation under the bending loading.

Cross-ply Laminate, Matrix Cracking, Strain Energy Release Rate, Stiffness Reduction