Prediction of Strain Energy Release Rate of Asymmetric Double Cantilever Composite Beam in Mixed-mode I/II Delamination using Equivalent Lay-up

In this paper، the equivalent layup method to estimate the delamination initiation of asymmetric double cantilever beam (ADCB) is presented. A relation for critical strain energy release rates (SERR) of unidirectional (UD) and multidirectional (MD) laminates، as a criterion for crack growth initiation، was presented. For finite element analyses، the ADCB specimens were modeled in ABAQUS/Standard software and SERR is determined using the virtual crack closure technique (VCCT). According to this method، the ability of estimating delamination initiation without using experimental tests and finite element modeling of MD specimens is provided. This method reduces the volume of calculations FEM and experimental tests significantly. Accuracy of the proposed method has been verified by experimental data. Also، the total strain energy release rate analyzed by this method is compared with the FEM and theoretical results. Results show that SERR of MD lay-ups can be predicted by measuring SERR of the unidirectional specimens using FEM method with an error less than 10%.