Numerical Simulation Approach for Low-Velocity Impact Response of Bioinspired Layup Design in GFRP Laminates

This study investigates the out-of-the-plane impact response of glass/epoxy (GFRP) composite laminates with a bioinspired helicoidal stacking sequence. These hierarchical structures are commonly observed in fish scales, peacock mantis shrimp, etc. It has been observed that unique hierarchical structures prevent complete organ damage in these organisms and resist crack propagation during predator attacks. Therefore, this unique helicoidal structure can be a key factor in improving damage resistance properties in FRP composites. Here, we report the numerical simulation of the low-velocity indentation (LVI) on a GFRP composite using commercially available 3D simulation software: LS-DYNA (version 11.1.0). For impact studies, three stacking sequences, (i) single helicoidal, (ii) double helicoidal, and (iii) cross-ply, are considered. The LVI study is performed with a hemispherical steel impactor to identify the most suitable structure with the highest impact resistance characteristics. A GFRP laminate model of 11 layers (0.5-mm lamina thickness) was considered in the above-defined stacking sequences. The LVI response for all three stacking sequences was compared at velocities of 1 and 2 m/s as per ASTM D7136 standards. Numerical simulation results suggested that the single helicoidal stacking sequence performed relatively higher than the double helicoidal and cross-ply stacking sequences. The single helicoidal stacking sequences showed 20% more energy absorption capacity than the conventional cross-ply laminate.