A continuum damage description for a discrete crack modeling approach for delamination migration in composite laminates

Abstract

A three-dimensional discrete crack embedded within a continuum damage mechanics (CDM) model is developed for an effective characterization of delamination migration in composite laminates subjected to static loading. 3D Hashin failure criterion is implemented for damage initiation prediction under a 3D stress state. Matrix crack initiation criteria coupled with a maximum principal stress direction are employed to determine the location and orientation of a discrete matrix crack within an element. Given the orientation of the initiated matrix crack, the resulting stiffness degradation is characterized in the local principal stress coordinate system and an energy driven failure mechanism is included to capture the crack growth. By coupling the cohesive model for delamination and the discrete damage embedded CDM for matrix cracking, their synergistic interaction can be captured during the simulation of the delamination migration. The predictive capability of the enhanced modeling strategy is examined through simulation of a delamination migration in a cross-ply tap laminate. The predicted results are compared with the experimental data published by NASA and good agreements are achieved in terms of load displacement curve and the location of crack branching.