In this paper, an innovative bio-inspired multi-layered graded foam-filled structure (MGFS) mimicking the characteristics of the human skeleton was proposed in an attempt to improve the energy absorption. The proposed structures consisted of three layers of aluminum foam with different densities filled in three concentric aluminum circular tubes. To find out the optimal foam-filled combination and demonstrate the superior energy absorption performance of the proposed structures, a series of quasi-static compression tests were experimentally and numerically carried out. The results showed the proposed structures had higher energy absorption efficiency than that of both uniform foam-filled structures and the empty tubes, and Model-1 with the foam density increasing from the inner tube to the outer tube was the best combination mode. Furthermore, parametric numerical studies on Model-1 revealed that the diameter and thickness of the aluminum tube and the density of the aluminum foam had significant effects on the energy absorption characteristics. Finally, a theoretical model was developed to predict the mean crushing force of the bioinspired MGFS, which was in good agreement with the experimental results. This study provides an effective guideline for designing a foam-filled energy absorber with high energy absorption efficiency.

在本文中，提出了一种模仿人体骨骼特征的创新的生物启发式多层渐变泡沫填充结构（MGFS），以尝试改善能量吸收。拟议的结构包括三层不同密度的泡沫铝，并填充在三个同心的铝圆管中。为了找出最佳的泡沫填充组合并展示出所提出结构的优异能量吸收性能，通过实验和数值方法进行了一系列准静态压缩试验。结果表明，所提出的结构比均匀的泡沫填充结构和空管结构具有更高的能量吸收效率，并且随着泡沫密度从内管到外管的增加，模型1是最佳组合方式。此外，对Model-1进行的参数化数值研究表明，铝管的直径和厚度以及泡沫铝的密度对能量吸收特性有显着影响。最后，建立了理论模型来预测受生物启发的MGFS的平均压碎力，这与实验结果非常吻合。该研究为设计具有高能量吸收效率的泡沫填充能量吸收器提供了有效的指导。