Low-velocity impact response of sandwich composite panels with shear thickening gel filled honeycomb cores

Sandwich composite panels (SCPs) with carbon fiber reinforced plastic (CFRP) facings and honeycomb core are susceptible to impact damage. In this study, a method is proposed to improve the impact resistance and energy absorption capacity of SCPs by filling the honeycomb core with a shear-thickening gel (STG) mixed with silica particles. The low-velocity impact responses of the SCPs have been analyzed including the drop hammer ricochet from front facing, ricochet from back facing, and complete perforation. The load-displacement curves and damage patterns indicate that STG-filled honeycomb core could effectively decrease the penetration depth and reduce impact damage of the SCPs. Finite element simulations based on the Coupled Euler-Lagrangian (CEL) method were conducted to reveal the underlying mechanism for the enhanced anti-impact capacity of the SCP filled with STG.