Local Strengthening Design and Compressive Behavior Study of the Triangular Honeycomb Structure

Abstract

Additive manufacturing (AM) enables diversity in honeycomb structure configuration, which benefits optimization of the honeycomb structure. In the present study, we proposed two locally enhanced triangular honeycomb structures to improve in-plane compressive performance by avoiding diagonal fracture band. The compressive behaviors and failure mechanism of the original and enhanced triangular honeycomb structures made of 316L steel were studied by experiments and numerical simulations. The results show that the cell-enhanced triangular honeycomb structure and wall-enhanced triangular honeycomb structure possess significantly improved stiffness and peak load compared with the original structure. The fracture band along the diagonal direction of the triangular honeycomb structure is caused by buckling of the cell wall, which is related to its topologic structure. Stress distribution is an essential index reflecting the performance of a honeycomb structure. Uniform stress distribution makes the honeycomb structure fail layer by layer, and it can improve the peak load of the honeycomb structure. Defects such as unmelted metal particles and voids caused by AM processing weaken the strength and plasticity, and the resulting brittleness makes the honeycomb structure fall into pieces.