基于简化基本折叠单元法的蜂窝耐撞性优化设计

Crashworthiness Optimization Design of Honeycombs Based on the Simplified Basic Folding Element Method

采用简化基本折叠单元法,即基于简化基本折叠单元的超折叠单元理论对三种常用蜂窝结构的轴向平均压缩应力进行理论求解。为验证理论解的准确性,采用基于LS-DYNA的非线性有限单元法对这三种常用蜂窝结构的轴向压缩进行仿真计算,仿真结果与理论结果吻合很好。基于轴向平均压缩应力理论解,进一步采用多目标粒子群算法分别对这三种预压缩常用蜂窝结构的耐撞性进行多目标优化,发现在所研究的三种常用蜂窝结构中,正六边形蜂窝结构的耐撞性最好。采用LS-DYNA对优化设计的蜂窝结构进行轴向压缩仿真,仿真结果与基于所给出理论公式的耐撞性优化结果相差不大,说明基于所给出理论公式的蜂窝结构耐撞性优化是可行且有效的。

The mean crushing stresses of three kinds of commonly used honeycombs are calculated by using the simplified basic folding element（SBFE） method,which is actually the super folding element（SFE） theory based on the simplified basic folding element.In order to validate these theoretical solutions,the axial crushing simulation of the said honeycombs is implemented by employing the nonlinear finite element method through LS-DYNA.The analytical solutions show excellent agreement with these simulation results.Based on the theoretical solutions of the mean crushing stress,the crashworthiness of the pre-crushed honeycombs is multioptimized by using the multiobjective particle swarm optimization（MOPSO） algorithm.It is found that the energy absorption capacity of regular hexagonal honeycomb is the most excellent among those of the said honeycombs.Finally,three optimized honeycomb structures under axial dynamic loading are simulated by using LS-DYNA.The numerical simulation results correlate with the analytical results obtained by our crashworthiness optimization very well.This indicates that the crashworthiness optimization of honeycombs based on our deviational theoretical expressions is feasible and effective.