Damage evolution analysis of open-hole tensile laminated composites using a progress damage model verified by AE and DIC

A three-dimensional finite element model of composite laminates for progressive damage analysis has been established based on continuum damage mechanics. The model contains four kinds of damage modes of composite laminates under three-dimensional stress states, which include matrix damage, fiber breakage, delamination and fiber pull-out. Damage initiations adopt the mixed failure criterion composed by Linde criterion and Hashin criterion, which choose strain as parametric description. An improved exponential non-linear evolution model is adopted for damage variables, which take into account the effect of material dissipated energy on the damage variables. The damage variables calculated by material dissipated energy are different from that calculated by fracture dissipation energy employed by Linde, the material dissipated energy is the result of various damage accumulation of composite material, which can reflect the gradual damage evolution process of material. The progressive damage simulations have been performed to investigate damage evolution of unidirectional laminate and bidirectional laminate with a hole under tension, the damage evolutions simulated by FEA have a good agreement with that obtained from real-time acoustic emission (AE), digital image correlation (DIC) monitoring and load–displacement relationship, which validate efficiency of the proposed 3D FEM model.