A Theory for Progressive Matrix Cracking in Composite Laminates

The progressive matrix cracking of composite laminates that contain a cracked 90° ply and subject to uniaxial tensile or shear loading is modeled using a fracture mechanics approach and an elasticity theory. Closed form solutions are obtained for lami nate stiffnesses and Poisson's ratio as function of crack density or load level. This analysis only requires some basic mechanical and thermal properties obtained from uniaxial ply testing. Good agreement between theoretical prediction and experimental data is generally acquired from the comparison of laminates with four material systems.