Performance of multi-layered honeycomb sandwich composites under low-velocity impact

Abstract

This paper presents experimental, analytical, and numerical models to predict the response of multi-layered sandwich composite panels under low-velocity impact loading. The sandwich panels’ skin consists of a twill carbon-reinforced epoxy resin, whereas the core comprises a 2D Nomex honeycomb. The panels are then subjected to transverse impact loading to investigate their impact behaviour. Analytical models were developed based on a spring-mass system to predict the dynamic behaviour of the striker-multi-core-sandwich plate domain and, finally, to determine the contact force history, which represents the main novelty of this research. The analytical models incorporate the effect of variable core and skin distribution to identify the most suitable combination for four designs under impact loading. These experimental results are then used to verify analytical and numerical models constructed in LS-Dyna. The finite element models of the honeycomb-reinforced sandwich panels are also investigated using MAT-054 and MAT-26 material cards in LS-Dyna to find the most economical computational approach. Finally, the energy-absorption characteristics calculated by analytical models are used to evaluate the performance of the multi-layered sandwich composite and to provide design recommendations. The specific energy absorption (SEA) under low-velocity impact (8.8 J) was compared across designs, revealing that the single-core panel achieved the highest SEA (78 J/kg), while multi-core and thicker builds provided higher stiffness and peak loads but reduced mass efficiency.