An Efficient Continuum Damage Model and its Application to Shear Deformable Laminated Plates

In this article an efficient 3-D continuum damage mechanics formulation for composite laminates and its implementation into a finite element model that is based on the first order shear deformation theory of laminates are described. In the damage formulation each composite ply is treated as a homogeneous orthotropic material that can exhibit orthotropic damage in the form of distributed microscopic cracks that are normal to the three principal material directions. This type of damage is efficiently described by a symmetric second order tensor field that serves as an evolving internal variable within the framework of irreversible thermodynamics. The damage tensor is continuous within each material ply of a given element, but can be discontinuous across material layer boundaries and inter-element boundaries. The resulting finite element formulation is shown to be robust, stable and efficient for the simulation of progressive damage and global failures in large-scale composite laminate problems. Numerical examples are provided to demonstrate the performance characteristics of the finite element model, which is shown to provide consistent results over a range of different element types, mesh densities, element distortion levels and element integration schemes.

ACKNOWLEDGEMENT

The research reported herein was carried out on an SBIR Phase II contract (DAAE07-03-L019) from TACOM (AMSTA-AQ-ABGD-W).