中文摘要：

梯度及梯度排布是密度梯度多孔材料设计中的关键性问题。该文基于分层梯度金属空心球阵列模型，重点讨论了不同冲击速度下，梯度分布对金属空心球阵列动力学性能的影响。研究结果表明：在低速冲击下，梯度金属空心球阵列的动力学响应只取决于梯度的大小而不敏感于梯度的空间分布；而在中高速冲击下，梯度金属空心球阵列的动力响应不仅取决于梯度的大小，而且必须考虑梯度的空间分布。一定冲击速度下，梯度分布决定了材料内部的应力分布和材料的能量吸收过程，但吸收的总能量由材料的相对密度决定。考虑到对被冲击防护结构的保护，从冲击端高密度向远端低密度的梯度分布更有优势。该文的结论为实现多孔材料冲击动力学性能的多目标优化设计提供了新的设计思路。

英文摘要：

The determinations of gradient and gradient profile are the key point in the design of density graded metal hollow sphere arrays. In this paper, the influence of the gradient profile on the dynamic responses of density graded metal hollow sphere arrays is investigated. The results show that under a low velocity impact, the dynamic responses of density graded metal hollow sphere arrays only depend on the gradient. Whilst under a medium or high velocity impact, the dynamic properties rely not only on the gradient, but also on the gradient profile. Under certain impact velocity, the gradient profile determines the stress distribution, but the energy absorption relies on the relative density of the materials. Considering the protection to structures, the gradient profiles with the high density layer near the impact end and the low density layer near the distal end are recommended. The results will provide valuable suggestions in the multi-objective optimization design of impact dynamic properties of porous materials.