高孔隙率泡沫金属材料由于其具有较长的应力平台可以吸收较多的能量，在结构耐撞性设计中有重要的应用前景。本文通过实验研究和数值模拟发现：开孔铝泡沫材料在较高撞击速度作用下，会出现输出端的应力比加载端的应力增大，从而使被保护的物体受到更严重的伤害，此时开孔铝泡沫材料的变形尚未进入密实化阶段。这与人们采用多孔金属材料作为防撞性材料目的正好相反，必须给予重视。随着试件厚度的增加，出现这种应力增强的时间延迟。不同孔径、不同相对密度的开孔铝泡沫材料在不同撞击速度的作用下，应力时程曲线变化趋势基本相同，而且也会出现应力增强。本研究可以为防护装置可靠性评估和新型泡沫金属材料的设计提供依据。
Abstract
Cellular metallic materials possessing relatively long stress plateau, can absorb a lot of energy and have significant applications in the design of structural crashworthiness. In this paper, experimental studies and numerical simulations prove that: a) Under intense impact loads, the output stress of the aluminum foam with open cells is larger than the input one, which may severely damage the substance under protection, but the foam is not fully consolidated yet. This provides an opposite proof to our purpose of using cellular material as crash material and must be taken into account. b) With the increase of the thickness of test pieces, the occurrence of stress enhancement is prolonged. c) Under different impact loads, the trends of the stress time history curves of the aluminum foam materials with different cell sizes and relative densities are basically the same and stress enhancement happens in all these materials. This investigation provides a basis for the reliability evaluation of protective devices and the design of new cellular metallic materials.
关键词
多孔金属材料 /
开孔铝泡沫 /
应力增强 /
撞击速度
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Key words
cellular metallic material /
open cell aluminum foam /
stress enhancement /
impact velocity
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参考文献
[1] Gibson L J, Ashby M F. Cellular Solids: Structure and Properties [M]. Second Edition. Cambridge University Press, Cambridge, 1997: 2- 371.
[2]Reid S R, Peng C. Dynamic uniaxial crushing of wood[J]. International Journal of Impact Engineering. 1997, 19: 531～570.
[3] S.Pattofatto，I. Elnasri，H. zhao，et al. Shock enhancement of cellular structures under impact loading: Part II Analysis[J]. Journal of the mechanics and physics of solids 2007,55: 2672-2686
[4]Reid S R, Reddy T Y. Experimental investigation of inertia effects in one-dimensional metal ring systems subjected to impact I: Fixed-ended systems. International Journal of Impact Engineering. 1983, 1: 85～106.
[5]Cooper G J , Townend D J, Cater S R, Pearce B P. The role of stress waves in thoracic visceral injury from blast loading: modification of stress transmission by foams and high-density materials. J Biomech., 1991, 24(5): 273–85.
[6]Shim V P W, Tay B Y, Stronge W J. Dynamic crushing of strain-softening cellular structures--a one-dimensional analysis. Trans. ASME. J. Engng. Mater. Tech.. 1990, 112: 398～405.
[7]康锦霞. 多孔金属材料应力/力增强现象的研究[D]. 太原理工大学博士学位论文.2012.5
kang jinxia. investigation on the stress/force enhancement of the cellular metallic materials[D]. Taiyuan University of Technology.2012.5(in Chinese)
[8]寇东鹏等.随机缺陷对蜂窝结构动态行为影响的有限元分析[J]. 力学学报, 2009，41(6):859～868
Kou dongpeng, et al.effect of randomly removing cell walls on the dynamic crushing behaviour of honeycomb structures[J].
Chinese Journal of Theoretical and Applied Mechanics. 2009, 41(6):859～868
[9]刘耀东等. 惯性对多孔金属材料动态力学行为的影响[J]. 高压物理学报，2008，22(2):118~124
Liu YaoDong, et al. Effect of Inertia on the Dynamic Behavior of Cellular Metal[J]. Chinese journal of high pressure physics, 2008，22(2):118~124
[10]李斌潮等. 闭孔金属泡沫中应力波的传播特性分析[J]. 兵工学报，2009，30(2):38～41
Li Bin-chao, et al. Propagation Characteristics of Stress Wave in Closed -cell Metal Foam[J]. Acta armamentaria, 2009, 30(2)
:38~41(in Chinese)
[11]庞宝君等.基于Taylor实验及理论分析的泡沫铝动态冲击特性研究[J]. 振动与冲击，2013，32(12):154～158
PANG Bao-jun, et al. Dynamic impact behavior of aluminum foam with a Taylor impact test and a theoretical analysis[J]. Journal of vibration and shock, 32(12):154～158. (in Chinese)
[12]潘艺，胡时胜，魏志刚. 泡沫铝动态力学性能的实验研究[J]. 材料科学与工程，2002，20(3): 341-343.
Pan Yi, HU Shi-sheng, WEI Zhi-gang. Experimental Study on Dynamic Behavior of Foamed Aluminum[J]. Materials Science & Engineering,2002, 20(3): 341-343.(in Chinese)
[13]王鹏飞，徐松林，郑航，胡时胜. 变形模式对多孔金属材料SHPB实验结果的影响[J]. 力学学报，2012，44(5): 928-932.
Wang Pengfei, et al. Influence of Deformation Modes on SHPB Experimental Results of Cellular Metal[J]. Chinese Journal of Theoretical and Applied Mechanics,2012,44(5): 928-932.(in Chinese)
[14]王礼立编著，朱兆祥审校. 应力波基础（第二版）(M).国防工业出版社.2010.1，北京
Wang lili. Foundation of stess waves(the second) (M). National Defense Industry Press. 2010.1, beijin. (in Chinese)
[15]Chen W, Zhang B, Forrestal M J. A split hopkinson bar technique for low-impedance materials [J]. Experimenta Mechanics, 1999, 39: 81~85.
[16]胡时胜. Hopkinson 压杆实验技术的应用进展[J]. 实验力学，2005:20(4):589-594.
HU Shi-sheng. The Application Development of Experimental Technique of Hopkinson Pressure Bar[J]. Journal of Experimental Mechanics. 2005:20(4):589-594. (in Chinese)
[17]P.J. Tan, S.R. Reid et al. Dynamic compressive strength properties of aluminium foams. Part I—experimental data and observations [J]. Journal of the Mechanics and Physics of Solids . 2005,53: 2174–2205.
[18]Liu Y.D., Yu J.L., Zheng Z.J., et al. A numerical study on the rate sensitivity of cellular metals[J].International Journal of Solids and Structures2009,46:3988–3998.
[19]LS-DYNA KEYWORD USE’S MANUAL. LIVERMORE SOFTWARE TECHNOLOGY CORPORATION.2003.4
[20]Hallquist J.O. Ls-Dyna theoretical manual. Livermore Software Technology Corporation, 1998.
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