Low velocity impact behavior and simulation of parametric effect analysis for UHMWPE/LLDPE thermoplastic composite laminates

Low-velocity impact tests are conducted using split Hopkinson pressure bar (SHPB) for investigating the impact behavior of the cross-ply ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced linear low-density polyethylene (LLDPE) thermoplastic composite laminates. And, the three-dimensional finite element (FE) model is established by using the LS-DYNA explicit dynamics finite element program and verified by comparing with the experimental results. Based on the FE models, the effects of impact energy, ply angle and interfacial strength on the low-velocity impact performance of the composite laminates are discussed. The analysis reveals that the impact energy is mainly dissipated by the plastic deformation and delamination damage of the laminates. For the cross-ply laminates, when the impact energy is about 10.36 J, it exhibits the best energy absorptivity. The introduction of the 45°/−45° sub-laminates has improved the material stiffness and reduced the impact energy absorptivity. The number of the introduced 45°/−45° sub-laminates is inversely proportional to the energy absorptivity and the impact responses has little relationship with the position of 45°/−45° sub-laminates. Then, the parametric analysis of the interfacial strength has revealed that the optimum interfacial properties are needed for obtaining the best impact resistance of UHMWPE/LLDPE laminates.