金属空心球梯度泡沫结构抗冲击特性仿真与优化

Simulation and optimization for anti-shock performances of graded metal hollow sphere foam structure

基于有限元方法,研究不同冲击速度下面心立方排布的金属空心球(FCC-MHS)梯度泡沫结构的缓冲吸能特性.以比吸能和远端应力为目标对象,分析梯度排列次序和梯度数对结构抗冲击性能的影响.采用径向基函数方法构建FCC-MHS梯度泡沫冲击代理模型且进行多目标优化.结果显示,在冲击波效应不明显时,梯度排列次序和梯度数对FCC-MHS泡沫抗冲击性能影响有限,FCC-MHS梯度泡沫的抗冲击性能与均质FCC-MHS泡沫接近;在波效应明显的冲击速度下,梯度数多且呈负梯度排列的FCC-MHS泡沫抗冲击性能最优.优化设计能使FCCMHS泡沫的抗冲击性能更优.

Based on the finite element method,crashworthiness of a face center cubic metal hollow sphere(FCC-MHS)graded foam structure under various impact velocities were investigated.Specific energy absorption and distal end stress were taken as performance indexes,and the influence of density gradient rank and number on the structure crashworthiness were analyzed.The replaced model for crashworthiness prediction of the FCC-MHS foam was established by using radial basis functions,The multi-objective design optimization was performed.Rresults shows that when the FCC-MHS foam subjects a shock load with less obvious wave effect,the gradient rank and number have limited influence on its crashworthiness.At that time,the performance of the graded FCC-MHS foam is similar to that of the uniform density foam.When it subjects to impact with obvious wave effect,the graded FCC-MHS foam with more gradient number and anti-gradient rank shows the best performance.Multi-objective design optimization of the graded FCC-MHS foam structure can improve its crashworthiness.