An Experimental and Numerical Investigation on the Low-Velocity Impact Response of Nanoreinforced Polypropylene Core Sandwich Structures

The impact behavior of sandwich structures was studied using experimental and numerical methods. Polypropylene with 0.5 wt% of graphene (PP/0.5% G) or pure polypropylene (PP) was sandwiched between aluminum face sheets for experimental tests. Impact tests revealed that the nanoreinforced structures had a higher contact force and a shorter contact duration than pure core structures. Both the damage area and the dent depth were lower for nano-reinforced structures. More energy absorbed the pure structures. The higher absorbed energy can be explained by the higher amount of damage that occurred in the structure. To further investigate the impact response of the sandwich structures, a three-dimensional quarter model was developed and implemented in the ABAQUS software. The strain-rate-dependent behavior of the core and face sheets was investigated using the Johnson-Cook material model to simulate the impact behavior of aluminum, PP, and G/PP layers. Simulation results were compared with experimental data, and a good agreement between them was found to exist. The validated finite-element model was used for studying the effects of geometrical and material parameters, including the thickness of aluminum and PP layers, different weight ratios of nanoparticles, and different mechanical properties of the aluminum layers, on the impact response of sandwich structures. By introducing graphene up to 0.5 wt% into the PP material, all of the impact outputs reached their extremum amounts, which were considerably affected by the yield strength and elastic modulus of aluminum layers.

Automated summary

The impact behavior of sandwich structures was studied using both experimental and numerical methods. The results showed that nanoreinforced structures had higher contact force and shorter contact duration, resulting in smaller damage area and dent depth. A validated finite element model was used to investigate the effects of different parameters on the impact response of sandwich structures.