Impact performance of rhombic honeycomb structures with non-uniform wall thickness

A novel non-uniform wall thickness rhombic (NTR) honeycomb structure was developed, with a particular emphasis on its energy absorption characteristics. In contrast to conventional uniform wall thickness configurations, the NTR honeycomb structure is characterized by a regular geometric (stiffness) distribution of unit cells throughout the entire panel. Nylon was employed as the primary energy-absorbing material in the structure. A combined approach of numerical simulation and experimental testing was utilized to systematically investigate the dynamic response and energy absorption mechanisms of the NTR honeycomb structure under various loading conditions. The dynamic response of the nylon-based honeycomb structure under impact loading was investigated using ABAQUS simulation software, and the numerical results were validated against experimental data. Additionally, a comparative analysis was performed between the reaction forces at the base of the nylon-based NTR honeycomb structure and those of a rigid body under varying impact velocities. The time at which the structure reached its maximum compression, as well as the evolution of kinetic energy at different impact speeds, was also investigated. With increasing velocity of the impact plate, the occurrence time of the maximum compression in the nylon-based structure was progressively advanced. The higher the velocity of the impact plate, the earlier the maximum compression of the nylon material occurs. Specifically, at a velocity of 15 m/s, the time of occurrence is 106% earlier than that at 7 m/s. In contrast to rigid bodies, the nylon material exhibits a significant delay in the occurrence time of the peak reaction force on the bottom plate, accompanied by a Substantial reduction in the peak magnitude. When the impact plate velocity is 7 m/s, the time to peak reaction force for the nylon material is 31% delayed and the peak value is 60% lower compared to the rigid body. As the impact velocity increases, the initial kinetic energy of the impact plate decreases while the internal energy increases, with both eventually converging to stable values. This trend confirms the energy absorbing capability of the structure.