A semi-analytical model for the energy release rate analyses of composite laminates with a delamination

In this paper, by combining a semi-analytical solution for sub-laminates and a linear spring-layer between sub-laminates a efficient semi-analytical model for the pointwise energy release rate of composite laminates with a linear or curve delamination front is presented. One of the main advantages of present model is that the finite element mesh is only used in plane of sub-laminates due to the transfer matrix technique being employed. As a result, the scale of final control equation involves only the so-called state variables at the top and bottom surfaces of such structures. In terms of the virtual crack closure technique (VCCT), the model is validated by comparing the numerical GI, GII, and GIII of double cantilever beam specimens with those from existing examples. To show the applicability and efficiency of the proposed approach, an angle-ply plate with a curve delaminate problem is presented in the numerical examples.