A synergistic damage mechanics approach to mechanical response of composite laminates with ply cracks

摘要

We treat selected test cases in the third world wide failure exercise by the approach described as synergistic damage mechanics. This approach utilizes micromechanics and continuum damage mechanics to predict the overall mechanical response of composite laminates with ply cracking in multiple orientations. The material constants needed in the continuum damage mechanic formulation are calculated from stiffness property changes incurred in a reference laminate. For other laminate configurations, the stiffness changes are derived using a relative constraint parameter which is calculated from the constraint on the opening displacement of ply cracks within the given cracked laminate evaluated numerically by a finite element analysis of appropriately constructed representative unit cell. The number density of ply cracks (cracks per unit length normal to the crack planes) under quasi-static loading is calculated by an energy-based approach. Finally, the stress-strain response of a laminate is determined by combining stiffness property changes and evolution of crack number density.