具有吸能和承载特性的多孔结构拓扑优化

Topological optimization of porous structure with energy absorption and loading capability

以负泊松比和刚度为优化目标,构建多目标拓扑优化模型.利用改进的优化准则(OC)算法求解该模型,得到兼具吸能和承载性能的多孔结构,并利用选择性激光熔覆技术(SLM)制造该多孔结构.通过对优化结构进行有限元仿真和压缩实验及分析,得到多孔结构的形变图、应力-应变曲线及能量吸收曲线.分析结果表明:等效刚度大的结构负泊松比值较小,受压内缩量小,平台应力和能量吸收量大,但易出现应力峰值;等效刚度小的结构负泊松比值较大,受压内缩效果明显,平台应力和能量吸收量小,但平台应力平稳,能量吸收增量大.模拟仿真和实验测试验证了本方法用于耐撞承载结构的拓扑优化设计的有效性.

In order to obtain the porous structure with both energy absorption and loading capacity,a multi-objective topological optimization model of negative poisson and stiffness was constructed.By using the improved optimization criteria(OC)algorithm,the model was solved,and a porous structure with both energy absorption and loading capacity was fabricated by selective laser melting(SLM)technology.Through the simulation of finite element simulation,compression experiment and analysis of the optimized structure,the deformation diagram,stress-strain curve and energy absorption curve of porous structure were obtained.The results show that the structure with large equivalent stiffness is proved to have smaller negative Poisson’s ratio,less compression effect,more platform stress and more energy absorption,but it is prone to peak stress.The structure with small equivalent stiffness is proved to have lager negative Poisson’s ratio,more obvious pressure contraction effect,smaller platform stress and smaller energy absorption,but has more stable platform stress,and bigger energy absorption increment.The simulation and experimental results show that the proposed method can be used in the topology optimization design of the collision-resistant bearing structure effectively.