Analysis on Low-Velocity Impact Damage of Laminated Composites Using CDM and CZM Models

摘要

The hierarchical and heterogeneous structure characteristics of composite laminates give rise to the difficulty in the study of the composite laminates damage under low-velocity impact. A numerical method for the evaluation of impact damage is proposed on the basis of the continuum damage mechanics (CDM) and the cohesive zone model (CZM). The intra-ply damages including matrix crack and fiber fracture are represented by the constitutive model which takes into account the physical progressive failure behavior in the ply, using the damage variable to describe the intra-ply damage state. The delamination at the interface between two plies is characterized by the CZM which takes into account the normal crack and the tangent slip, using a specific correlation between traction and separation displacement to describe the initiation and development of delamination. The evolution of the impact damage is investigated, and the correlation between the mesoscale structure and the macroscopic response under impact is constructed effectively by finite element analyses. From the top to the bottom of the specimen, the delamination area increases, which is consistent with the conic distribution of the delamination under impact observed in the experiment. The dynamic analysis is helpful for a thorough understanding of the evolution of low-velocity impact damages in composite laminates.