Evaluation the energy release rate of induced delamination due to matrix cracking in symmetric composite laminate

In this study, by using an energy-based method, growth of induced delamination due to matrix cracking has been studied in symmetric composite laminates subjected to constant in-plane stresses as well as thermal stresses. Two unconstrained and generalized plane strain states have been analyzed here. Matrix cracking as a primary assumption has been supposed in both states and the impact of matrix cracking and delamination on the stiffness degradation is calculated. Then, some thermoelastic constants are proposed. By relating stiffness matrix elements using these constants, a simple equation due for energy release rate due to delamination formation is derived. The accuracy of developed relations is examined using ANSYS finite element software. The obtained results reveal that there is good agreement between the extended and FE approaches