In-plane impact dynamics of thickness gradient honeycomb structures with negative Poisson’s ratio multi-arc concave cells
Zhixi Guo, Junhua Xiao
Abstract
Based on a novel multi-arc concave cell, four types of thickness gradient honeycomb structures with positive gradient, negative gradient, symmetric positive gradient, and symmetric negative gradient are constructed by changing cell wall thickness, and the relative density of the structure is deduced. The in-plane impact dynamics of gradient structure are revealed by numerical method. The deformation collapse mode, the dynamic response curve, the energy absorption effect, and the platform stress of different gradient arrangement and impact velocity are analyzed. It is found that gradient arrangement and impact velocity have significant effects on the impact properties of the thickness gradient honeycomb structures. When the impact velocity is low, the structure shows laminar shrinkage deformation, but this phenomenon will gradually disappear with the increase of impact velocity. The results show that the energy absorption capacity of the negative gradient structure is the best under different impact velocities. The platform stress is greatly affected by the impact velocity and less affected by the gradient arrangement.