Fracture behaviors of explosively driven TA2 alloy cylinders under different loadings
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摘要: 金属柱壳破坏过程与材料、结构及载荷等相关，断裂结果呈现多种形式，采用有限元结合实验对不同爆炸载荷作用下，TA2钛合金圆管的破坏机制开展研究。有限元结果显示：对于理想均质柱壳，由于冲击波传播使壁厚中间形成二次塑性区，圆管壁厚中部的等效塑性应变总是大于内、外壁。在较高爆压下，裂纹在加载阶段从试样壁厚中部起始，沿45°或135°向内外壁剪切扩展；而在较低爆压下，破坏发生在自由膨胀阶段，断裂从内壁起始向外壁剪切扩展，两者破坏过程和机制不同，总体来说，与实验现象符合较好。相关实验中出现的一些外壁拉伸断裂现象，可能与试样的几何、材料缺陷等因素相关，其对金属圆管爆炸破坏的影响值得进一步关注。Abstract: The failure process of an explosively driven TA2 alloy cylinder is related with its material, structure, loading, and so on, with its fracture behavior shown in various ways. In this paper we investigated the mechanism underlying this failure under different explosive loadings using numerical and experimental methods. The results of the finite element analysis showed that, during the driven period, for the ideally homogeneous cylinder, the equivalent plastic strain effect in the inner zone of the cylinder's thick shell, where the secondary plastic zone was formed due to shock wave propagation, was always larger than that on the inner and outer surfaces; under higher blast loading, the cracks originated first in the secondary plastic zone during the driven period and propagated to the inner and outer surfaces in an angle of 45° or 135° to the radial; for lower blast loading, the shear cracks, which originated first in the inner surface, propagated to the outer surface in an angle of 45° or 135° to the radial during the free expanding period; and, although the cracks were all shear cracks, their failure mechanisms differed. The simulated results and experiments agreed pretty well. The phenomenon that cracks originated in the outer surface, as reported earlier concerning some related experiments, might have been affected by the specimens' geometrical and material defects, whose influence on the cylinder's explosion-induced failure needs to be studied further.
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Key words:
- metal cylinder /
- explosive load /
- defect /
- finite element model
1) “第十一届全国爆炸力学学术会议”推荐论文 -
图 1 平面应变圆管爆炸加载模型
Figure 1. Finite element model of metal cylinder subjected to explosive load
图 2 圆管膨胀、破坏过程等效塑性应变演化
Figure 2. Equivalent plastic strain evolution of circular tube during expansion and failure
图 3 圆管外壁在不同爆轰载荷下的速度时程曲线
Figure 3. Histories of explosive load and outer surface velocity of circular tube under explosive load
图 6 高爆轰压力下沿壁厚各点应力时程曲线
Figure 6. Histories of stressalong thickness under higher pressure
图 7 高爆轰压力下沿壁厚等效应变演化特性
Figure 7. Development of equivalent plastic strain under higher pressure
图 8 低爆轰压力作用下内壁应力时程曲线
Figure 8. Histories of stress along thickness under higher pressure
图 9 低爆轰压力下等效应变演化发展特征
Figure 9. Development of equivalent plastic strain under lower pressure
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[1] GURNEY R W. The initial velocities of fragments from bombs, shell and grenades[R]. Army Ballistic Research Lab Aberdeen Proving Ground Md, 1943. [2] TAYLOR G I. Analysis of the explosion of a long cylindrical bomb detonated at one end[M]//Scientific Papers of G I Taylor. Cambridge: Cambridge University Press, 1963: 277-286. [3] TAYLOR G I. The fragmentation of tubular bombs[M]//Scientific papers of G I Taylor. Cambridge: Cambridge University Press, 1963: 387-390. [4] MOTT N F. Fragmentation of shell casings and the theory of rupture in metals[M]//Fragmentation of Rings and Shells: Shock Wave and High Pressure Phenomena. Springer Berlin Heidelberg, 2006: 295-325. [5] HOGGATT C R, RECHT R F. Fracture behavior of tubular bombs[J]. Journal of Applied Physics, 1968, 39(3):1856-1862. doi: 10.1063/1.1656442 [6] SINGH M, SUNEJA H R, BOLA M S, et al. Dynamic tensile deformation and fracture of metal cylinders at high strain rates[J]. International Journal of Impact Engineering, 2002, 27(9):939-954. doi: 10.1016/S0734-743X(02)00002-7 [7] GOTO D M, BECKER R, ORZECHOWSKI T J, et al. Investigation of the fracture and fragmentation of explosively driven rings and cylinders[J]. International Journal of Impact Engineering, 2008, 35(12):1547-1556. doi: 10.1016/j.ijimpeng.2008.07.081 [8] 胡海波, 汤铁钢, 胡八一, 等.金属柱壳在爆炸加载断裂中的单旋现象[J].爆炸与冲击, 2004, 24(2):97-107. http://www.bzycj.cn/CN/abstract/abstract9927.shtmlHU Haibo, TANG Tiegang, HU Bayi, et al. An study of uniform shear bands orientation selection tendency on explosively loaded cylinder shells[J]. Explosion and Shock Waves, 2004, 24(2):97-107. http://www.bzycj.cn/CN/abstract/abstract9927.shtml [9] 汤铁钢, 李庆忠, 孙学林, 等.45钢柱壳膨胀断裂的应变率效应[J].爆炸与冲击, 2006, 26(2):129-133. doi: 10.11883/1001-1455(2006)02-0129-05TANG Tiegang, LI Qingzhong, SUN Xuelin. Strain-rate effects of expanding fracture of 45 steel cylinder shells driven by detonation[J]. Explosion and Shock Waves, 2006, 26(2):129-133. doi: 10.11883/1001-1455(2006)02-0129-05 [10] 张世文, 金山, 刘仓理.含缺陷厚壁圆管爆轰膨胀断裂的数值模拟[J].应用力学学报, 2010, 27(3):622-625. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yylxxb201003036ZHANG Shiwen, JIN Shan, LIU Cangli. Simulation of the dynamic expanding process of thick-walled cylinder with defects[J]. Chinese Journal of Applied Mechanics, 2010, 27(3):622-625. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yylxxb201003036 [11] 金山, 张世文, 龙建华.缺陷对圆管膨胀断裂影响的实验研究[J].高压物理学报, 2011, 25(2):188-192. doi: 10.11858/gywlxb.2011.02.017JIN Shan, ZHANG Shiwen, LONG Jianhua. Experimental study on the influences of defects on expanding fracture of a metal cylinder[J]. Chinese Journal of High Pressure Physics, 2011, 25(2):188-192. doi: 10.11858/gywlxb.2011.02.017 [12] 王礼立.应力波基础[M].北京:国防工业出版社, 2005. [13] REN G, GUO Z, FAN C, et al. Dynamic shear fracture of an explosively-driven metal cylindrical shell[J]. International Journal of Impact Engineering, 2016, 95(9):35-39. https://www.sciencedirect.com/science/article/pii/S0734743X16302147 [14] 俞鑫炉. 爆炸加载下柱壳剪切断裂的机理研究[D]. 宁波: 宁波大学, 2014. http://cdmd.cnki.com.cn/Article/CDMD-11646-1015804446.htmYU Xinlu. Research on shear fracture mechanism of cylindrical shells subjected to explosive loading[D]. Ningbo: Ningbo University, 2014. http://cdmd.cnki.com.cn/Article/CDMD-11646-1015804446.htm -
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