中文摘要：

泡沫铝填充薄壁结构具有轻质、较大承载能力以及高效吸能特性,越来越多地应用于各种工程结构。提出一种新颖的轴向梯度泡沫填充薄壁结构,采用试验与数值分析的方法,系统地分析空管、均匀泡沫填充及梯度泡沫填充薄壁圆管在弯曲工况下的力学响应及能量吸收特性。研究发现,泡沫填充薄壁结构比空管具有更好的抗弯性能。与均匀泡沫填充结构相比,梯度泡沫不仅使得填充薄壁结构的变形模式从单褶皱模式变为多褶皱模式,截面扁化量和抗弯刚度损失显著减小,而且有效地提高了填充结构的承载力及吸能特性。为了进一步探索填充结构的最优耐撞性,结合Kriging近似技术与粒子群数值优化方法,对均匀泡沫和功能梯度填充泡沫薄壁结构进行多目标优化设计,得到了泡沫填充薄壁结构耐撞性的最佳参数匹配设计,并有效提高了结构的抗弯性能,为泡沫填充薄壁结构抗弯性设计提供了参考依据。

英文摘要：

Aluminum foam filled thin-walled structure has light weight, large bearing capacity and high efficient energy absorption characteristics, and it had widely applied in different kinds of engineering structures. A novel functionally graded foam（FGF） filled structure is presented, and the mechanical response and energy absorption characteristics of empty tube（ET）, uniform tube（UFT） and functionally graded foam tube（FGFT） under bending condition are studied by using experiment and numerical analysis method. It is found that the FGFT has more excellent anti-bending behavior than ET. Moreover, FGF not only changes deformation mode of thin-walled structure from single fold pattern to multi-folds pattern, and reduces the cross section flattening and the loss of rigidity, but also effectively improves carrying capacity and energy absorption characteristic of the thin-walled structure. Besides, to further explore the optimal crashworthiness of foam-filled structure, the numerical optimization is performed about UF and FGF thin-walled structures based on Kriging approximation technique and the particle swarm optimization algorithm（PSO）. Lastly, optimal design parameters of foam-filled thin-walled structures are obtained, meantime, the bend resistance of foam filled structures is improved efficiently. Therefore, the optimal design provides a reference for bend resistance design for the foam filled thin-walled structure.