Finite element simulation of low velocity impact damage on composite laminates

A 3D finite element model with cohesive was established for simulating composite laminated under transversely low velocity impact. The strain-based failure criterion of composite including fiber tensile failure, fiber compress failure, matrix crushing and matrix cracking with corresponding stiffness degradation technology, were adopted to model the in-plate damage. Cohesive elements were used for modeling the regions between two laminas. The initial and evolution of interlaminar damage was decided by a bilinear cohesive law which combines stress-based and facture-mechanics-based failure criterion. And a cohesive element initial damage strength function was introduced. A good agreement was obtained between numerical analysis and experimental results.