Design, simulation and experiment study of a snap-fit spatial self-locking system for energy absorption

Due to the strong destructiveness and poor predictability of the impact loading, energy absorption structures are easy to cause secondary damage in emergency situations. The proposed self-locking system for energy absorption can effectively solve this problem, but also can realize fast installation, disassembly and free editing. In this paper, a new snap-fit spatial self-locking energy absorption system is designed according to the self-locking idea of mortise and tenon structure. Firstly, the effects of concentrated loading, uniform distributed loading and friction properties on the self-locking characteristics under nine different spatial directions are studied by finite element simulation. Then, the crushing mechanism is revealed by impact experiment, and the performance and engineering adaptability of the existing self-locking energy absorption systems are compared. Finally, the design criteria for the system is derived. The results show that the system will not fly away under the impact loading in any spatial direction, and has good self-locking characteristics, while the friction properties have little effect on the self-locking characteristics of the system. In addition, under the uniform distributed loading, the deformation mode is the most regular in the direction 3, and the specific energy absorption in the direction 9 is as high as 7.07 J/g. Furthermore, when the total number of the structural unit in the self-locking energy absorption system is not less than twelve, the total energy absorption is linear with the number of layers, width and total number of the structural unit. Consequently, this study provides a new research idea for the design and feasibility of the self-locking energy absorption system.