Design And Characteristic Study Of Multi-stable Energy Absorption Structure

The ideal energy absorbing material should have the characteristics of light weight and high energy density.At the same time,the material can be reused many times and the energy absorbing effect is not affected by the loading rate.The traditional energy absorbing mechanisms such as the use of plastic deformation of metal and ceramic fragmentation can realize these properties at the same time,because these mechanisms depend too much on the excellent properties and destructive deformation of the material,so with the help of structural nonlinear deformation to achieve a new mechanism of energy absorption is proposed.It is found that the structure with multiple stable equilibrium states can convert the input energy into elastic strain energy,and the process can be repeated without being affected by the loading rate.In this paper,the energy absorption characteristics of multistable structures are studied in the following three parts:1.The " snap-through " process of bistable curved beams is analyzed by means of modal superposition principle.A series multistable mathematical model is proposed,and the deformation process of multistable structure is predicted by using the principle of minimum potential energy.The basic principle and basic research methods of multistable effect are expounded.2.The " snap-through " simulation analysis process of a single curved beam structure is used to illustrate how the multi-stable structure can absorb energy.Based on this,the influence of series-parallel design of bistable structure on response characteristics is further analyzed,and a prototype is made for experimental comparison and verification.3.Multi-stable curved shells are designed to meet more application scenarios.The material distribution of curved shell model is redesigned by using improved efficiency genetic algorithm and multi-stage objective optimization.The energy absorption effects of the optimized structure and the original structure are compared in detail,and the validation performance of the manufacturing model sample is verified.The data show that the optimized structure has higher specific energy absorption and more reasonable material layout.