CDM model for analyzing intralaminar strength of notched composite laminates based on the dissipation of strain energy

Based on the viewpoint of progressive damage evolution with energy realease, a continuum damage mechanics (CDM) model, including damage description, damage initiation criterion and damage evolution law, was proposed for intralaminar failure analysis of composite laminates. Based on the CDM model, the damage constitutive of material in plane stress condition was established by introducing damage state variables which characterize corresponding damage. The damage initiation was estimated by using rewritten Hashin's criteria, which was expressed with damage parameter f_E. The damage evolution was controlled by the density of strain energy release within the characteristic length. The progressive damage evolution law associating damage state variables with equivalent strain was established. Intralaminar shear nonlinearity and mesh sensitivity were also taken into accounts in the model and analyzed comparatively. Failure analysis of notched90/0/±45_3s and(±θ)_4s composite laminates under intralaminar tensile load was implemented, and the result shows that the present model is capable of predicting the intralaminar tensile strength of composite laminates.