Enhanced energy mitigation of thin-walled tube filled with liquid nanofoam under dynamic impact
Enhanced energy mitigation of thin-walled tube filled with liquid nanofoam under dynamic impact
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DOI：
10.1016/j.compositesb.2020.108047
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发表时间：
2020-07-15
影响因子：
13.1
通讯作者：
Lu, Weiyi
中科院分区：
文献类型：
--
作者：
Li, Mingzhe;Barbat, Saeed;Lu, Weiyi
由于流体状液体纳米泡沫（LN）填料与管壁之间的紧密接触，增强了填充LN的管（LNFT）中的填料-管壁相互作用，从而大大改善了复合结构的性能。然而，对LNFT的能量减缓性能和潜在的工作机制仍然缺乏全面的了解。本文旨在探讨液氮管在准静态压缩和动态冲击下的破碎行为，揭示液氮管在不同应变率下的工作机理，以及液氮管填料和管壁材料的选择准则。对不同LN填料的LNFT进行了一系列准静态压缩试验。LNFT的强化系数大于3.5。显微CT图像显示，液氮-管相互作用通过管壁的扩展塑性变形提高了LNFT的性能。在动态冲击下，LNFT的能量吸收能力比准静态试验下的能量吸收能力提高了54%，导致显著的增强系数为8.0。应变速率效应是由于LN填料的不同能量缓解机制，即在较低应变速率下的能量耗散和在较高应变速率下的能量捕获。为了优化LNFT的冲击缓解性能，最关键的系统参数是LN填料的渗透压力和总孔隙体积以及管壁的刚度和延展性。这些发现和研究成果促进了对LNFT冲击减缓机理的理解，并为LN基复合材料结构的设计提供了指导。
Due to the intimate contact between the fluid-like liquid nanofoam (LN) filler and the tube wall, the filler-tube wall interaction in LN-filled tube (LNFT) is enhanced, leading to a much-improved performance of the composite structure. However, a comprehensive understanding of the energy mitigation performance and the underlying working mechanism of LNFT is still lacking. This study aims to explore the crushing behavior of LNFT subjected to quasi-static compression and dynamic impact and reveal the working mechanism of LNFT at different strain rates and the selection criteria for LN filler and tube wall material. A series of quasi-static compression tests are conducted on LNFTs with various LN fillers. The strengthening coefficient of LNFTs is larger than 3.5. Micro-CT images show that the LN-tube interaction improves the performance of LNFT through extended plastic deformation of the tube wall. Under dynamic impacts, the energy absorption capacity of LNFT shows 54% increase compared to that under quasi-static tests, leading to a remarkable strengthening coefficient of 8.0. The strain rate effect is due to the different energy mitigation mechanisms of the LN-filler, i.e. energy dissipation at lower strain rate and energy capture at higher strain rate. To optimize the impact mitigation performance of LNFT, the most critical system parameters are the infiltration pressure and total pore volume of the LN-filler and the stiffness and ductility of the tube wall. These findings and research outcomes expedite the understanding of the impact mitigation mechanism of LNFT and provide design guidance for the LN-based composite structures.