Hybrid structures have the advantage of combining different types of materials at the same time. The trend of lightweight design in the transportation industry has promoted the development and application of composite materials with good crashworthiness performance. Low-density crushable foam-filled metal-composite hybrid structures have potential advantages as energy-absorbing components. This study investigated the mechanical characteristics of four different polyurethane foam-filled hybrid structures and their individual components under quasi-static axial compression. The experimental results showed foam-filled hybrid structures could change the deformation mode and improve stability during the compression process. Meanwhile, these hybrid structures could also improve energy absorption compared with their individual components. Among the different configurations, specimen C-PU-C (i.e., polyurethane foam filler between an outer CFRP tube and an inner CFRP tube) had the highest energy absorption capacity, at 5.4 kJ, and specific energy absorption, at 37.3 kJ/kg. Finally, a finite element (FE) model was established to analyze the mechanical characteristics of the hybrid structures by validating the simulation results against the experimental results.

中文翻译：

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聚氨酯泡沫填充金属/复合杂化结构能量吸收的实验与数值研究

混合结构的优点是可以同时组合不同类型的材料。运输行业轻量化设计的趋势促进了具有良好耐撞性能的复合材料的开发和应用。低密度可压碎泡沫填充的金属复合混合结构作为能量吸收组件具有潜在的优势。这项研究调查了准静态轴向压缩下四种不同聚氨酯泡沫填充混合结构及其各个组成部分的力学特性。实验结果表明，泡沫填充的杂化结构可以改变压缩模式并提高压缩过程的稳定性。同时，这些混合结构与其单个组件相比也可以提高能量吸收。在不同的配置中，样品C-PU-C（即外部CFRP管和内部CFRP管之间的聚氨酯泡沫填料）的最高能量吸收容量为5.4 kJ，比能量吸收为37.3 kJ / kg。最后，通过验证仿真结果与实验结果，建立了有限元模型来分析混合结构的力学特性。