Abstract: The ideal collision energy absorption structure should have certain carrying capacity while absorbing the collision energy to protect the safety of personnel and equipment better. However, the existing methods generally only conduct the design of collision energy absorption structure from a macro or micro perspective, the energy absorption and load-bearing requirements cannot be well considered. The gradient structure with gradient property has good collision energy absorption properties. Therefore, based on the macroscopic and microscopic integrated design idea, a macro-micro topology optimization method for gradient structures with energy absorption and load-bearing characteristics is proposed from the two aspects of macroscopic structure and single cell configuration. The load-bearing characteristics and the energy absorption characteristics are represented by the structural stiffness and the negative Poisson’s ratio, respectively. On the macroscopic scale, the optimization method of macroscopic region division with stiffness gradient is researched based on the functional gradient and cluster analysis theory. On the basis of the energy homogenization theory, a multi-objective topological optimization model with structural stiffness and negative Poisson’s ratio as the objective function is established on the microscopic scale. The energy absorption and load-bearing characteristics of the optimized structure are tested and analyzed by finite element simulation and compression experiment. The results show that the proposed method can be effectively applied to anti-collision structure design.

Key words: topology optimization, gradient structure, energy absorption characteristics, load-bearing characteristics