Effective 3D Constitutive Relations of Composites with Evolving Damage

In this study it is shown that a computational procedure, termed "discrete damage space homogenization method" (DDSHM), can predict the constitutive response of layered composite materials containing growing cracks. The fully 3D effective constitutive law for a specific layered composite architecture, as defined by the DDSHM, was integrated into the ABAQUS commercial finite-element program using the user-defined material feature. Calculations were carried out for flat laminates with penny-shaped microcracks to illustrate the computational efficiency of the method for general analysis of composite materials with growing cracks. Results show that, given basic information about the fracture toughness of the material, the DDSHM is able to predict important material parameters including the load at initiation of cracking, damage growth rate, and resulting effect on the macroscopic stiffness.