增强内凹蜂窝夹层结构弯曲力学性能及多目标优化设计OA

The catenary reinforced method can enhance the crashworthiness of re-entrant honeycomb (RH) by avoiding hollow structural characteristics,strengthening negative Poission's ratio effect,and utilizing the high load-bearing effectiveness of catenary structures. Based on the above effects the sandwich beam with reinforced RH (RRH) was proposed. The metallic specimens from the proposed structure were fabricated for three-point bending tests. Results show that the introduced catenary structure can limit the rotation deformation of inclined cell walls around vertices,and the drop in load-bearing force after initial plastic deformation is reduced from 29.3％ to 6.6％. Compared to classical RH cored beams,the maximum load-bearing force and energy absorption of RRH ones can be improved by 26.7％ and 8.9％,respectively. A parametric analysis was conducted to reveal that the thicknesses of front facesheet,back facesheet,and core had a significant effect on deformation behavior and energy absorption of RRH cored sandwich beams. The thickness of front facesheets,cores,and back facesheets was employed as optimization variables,and the mass,maximum load-bearing force,and energy absorption were used as optimization objectives to perform the multi-objective optimization of RRH cored sandwich beams. The optimized sandwich beam exhibits increases of 64.9％ in maximum load-bearing capacity and 46.9％ in energy absorption. The impact resistance of conventional honeycomb sandwich beams under in-plane and out-of-plane loading was compared at identical wall thickness and mass,respectively. Analysis demonstrated the superior energy-absorbing protective performance of the proposed RRH sandwich beams. The research results can provide useful guidance for the reinforcement design of honeycomb cored sandwich beams.