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. At an impact velocity of 15 m/s, the maximum compression occurred at 73.5 ms, with a corresponding deformation of 75.11 mm. Compared to the rigid body, the nylon-based structure exhibited a noticeable delay and reduction in the occurrence time and magnitude of the peak reaction force at the base. At an impact velocity of 7 m/s, the rigid body generated a peak reaction force of 134,489 N at 12.45 ms, whereas in the nylon-based structure, the peak was delayed to 16.35 ms and reduced to 53,342 N. With increasing impact velocity, the initial kinetic energy of the impact plate decreases while the internal energy increases, and both eventually approach stable values, indicating the energy absorption capability of the structure.