Experimental and numerical investigation on the ballistic impact performance of sandwich panels with additively manufactured honeycomb cores

The pursuance of lightweight yet robust materials and structures has led to the rapid evolution of protective technologies. Additive Manufacturing (AM) has emerged as a transformative tool, enabling the fabrication of intricate cellular structures with tailored properties. The use of additively manufactured honeycombs in the field of ballistic protection has not been explored extensively. In this view, the current work presents a comprehensive investigation involving experimental and numerical procedures, to understand the impact response of sandwich panels embedded with additively manufactured honeycomb cores against ogive and conical projectile impacts. Three different honeycomb cores, namely Hexagonal, Star, and AuxHex are additively manufactured using AlSi10Mg powder via selective laser melting technique. Each core is bonded to a pair of 1 mm thick SS 316 sheets. The projectiles are launched at velocities varying between 180 m/s and 260 m/s. Finite element models are created in ABAQUS/Explicit to simulate ballistic impact scenarios. A strong consistency between the predicted results and experimental outcomes in terms of deformation, damage modes and residual velocities was obtained. The results revealed that the sandwich panel featuring an AuxHex core exhibits a superior energy absorption capacity, absorbing 15 % and 12 % more energy than hexagonal and star cores, respectively. Additionally, it was observed that, when compared to a conical projectile, an ogive projectile requires 14 % more energy to perforate the same sandwich panel. Furthermore, the ballistic limit of star and AuxHex panels is found to be increased by 5 % and 9 %, respectively compared to panels with hexagonal honeycomb cores. This work contributes valuable insights into the application of additively manufactured honeycomb cores, offering potential scope for the development of lightweight and resilient structures crucial in aerospace and defense industries.