Simulation of dynamic compression of plastic-bonded explosives considering heterogeneous structure
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摘要: 采用离散元方法，构建了考虑PBX炸药晶体颗粒与黏结剂非均匀性的计算模型，通过在炸药试样两端采用相向飞片加载、将原SHPB实验的应力边界替代为速度边界的方法，开展了PBX炸药的动态压缩数值模拟研究，再现了考虑PBX炸药非均质特性的SHPB实验过程，获得了不同加-卸载路径下炸药应力应变曲线以及相应的损伤破坏图像。模拟结果表明：在动态压缩过程中，虽然PBX炸药处于整体应力平衡，由于PBX高度非均质性，内部应力分布并不均匀，晶体间应力以应力桥形式传递；应力曲线为试样整体平均，试样内局部所受真实应力可能高于曲线峰值应力；出现卸载回滞曲线的试样发生局部损伤破坏，而完全软化曲线的试样发生整体失稳破坏。Abstract: The plastic-bonded explosives (PBX) simulation model with heterogeneous crystal grain and binder was presented using the discrete element method(DEM). By loading opposite flyers at both ends of the explosive sample, the dynamic compression simulation was performed adopting velocity as the boundary condition instead of stress as the boundary condition in the Hopkinson test, and replicated the compression process in the Hopkinson test. The stress-strain curves and their corresponding damage fracture images under different loading-unloading paths in the explosive sample were captured. Our simulation results indicated that the stress distribution in PBX is not uniform and the stress propagates in the form of stress bridges between crystals due to the heterogeneous structure. The actual stress in PBX can be higher than that shown by the curve's peak stress. The samples on the unloading hysteresis curves reveal local damage, while those on the completely softening curves indicate fractures resulting from integral instability.
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图 4 弹性阶段初期的应力分布与细观结构
Figure 4. Stress distribution and meso-structure at early elastic stage
图 6 弹性阶段后期的应力分布与细观结构
Figure 6. Stress distribution and meso-structure at later elastic stage
图 8 强化阶段的应力分布与细观结构
Figure 8. Stress distribution and meso-structure at hardening stage
图 10 应变软化阶段初期的应力分布与细观结构
Figure 10. Stress distribution and meso-structure at early strain softening stage
图 12 应变软化阶段后期的应力分布与细观结构
Figure 12. Stress distribution and meso-structure at later strain softening stage
表 1 材料参数
Table 1. Material parameters
材料 ρ/
(g·cm-3)c0/
(km·s-1)λ aij/GPa m n μij G/
GPaCn/
(Pa·s)εy εb HMX 1.9 2.9 2.06 1.85 1.0 3.0 0.1 10.74 11 0.02 0.005 黏结剂 1.1 2.3 1.70 7.80 1.0 2.0 0.1 6.80 11 0.10 0.020 
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[1] Goudrean G. Evaluation of mechanical properties of PBXW-113 explosive[R]. CA, USA: Lawrence Livermore National Laboratory, 1985. [2] Hoffman H J. High-strain rate testing of gun propellants[R]. AD-A208826, 1989. [3] Blumenthal W R. Compressive properties of PBXN-110 and its HTPB-based binder as a function of temperature and strain rate[C]//12th International Detonation Conference. 2002. [4] 李英雷, 李大红, 胡时胜, 等.TATB钝感炸药本构关系的实验研究[J].爆炸与冲击, 1999, 19(4):353-359. http://www.bzycj.cn/article/id/10367Li Yinglei, Li Dahong, Hu Shisheng, et al. An experimental study on constitutive relation of TATB explosive[J]. Explosion and Shock Waves, 1999, 19(4):355-359. http://www.bzycj.cn/article/id/10367 [5] 吴会民, 卢芳云, 卢力, 等.三种含能材料力学行为应变率效应的实验研究[J].含能材料, 2004, 12(4):227-230. doi: 10.3969/j.issn.1006-9941.2004.04.008Wu Huimin, Lu Fangyun, Lu Li, et al. Experimental studies on strain-rate effects of mechanical behaviors of energetic materials[J]. Energetic Materials, 2004, 12(4):227-230. doi: 10.3969/j.issn.1006-9941.2004.04.008 [6] 傅华, 李俊玲, 谭多望.PBX炸药本构关系的实验研究[J].爆炸与冲击, 2012, 32(3):231-236. doi: 10.3969/j.issn.1001-1455.2012.03.002Fu Hua, Li Junling, Tan Duowang. Experimental study on constitutive relations for plastic-bonded explosives[J]. Explosion and Shock Waves, 2012, 32(3):231-236. doi: 10.3969/j.issn.1001-1455.2012.03.002 [7] 赵玉刚, 傅华, 李俊玲, 等.三种PBX炸药的动态拉伸力学性能[J].含能材料, 2011, 19(2):194-199. doi: 10.3969/j.issn.1006-9941.2011.02.016Zhao Yugang, Fu Hua, Li Junling, et al. Dynamic tensile mechanical properties of three types of PBX[J]. Energetic Materials, 2011, 19(2):194-199. doi: 10.3969/j.issn.1006-9941.2011.02.016 [8] Skidmore C B, Phillips D S, Howe P M. The evolution of microstructural changes in pressed HMX explosives[C]//Short J M, Kennedy J E. Paper Summaries-Eleventh International Detonation Symposium. Snowmass, 1998: 268-272. https://www.researchgate.net/publication/236569755_The_evolution_of_microstructural_changes_in_pressed_HMX_explosives [9] Rae P J, Goldrein H T, Palmer S J P. Studies of the failure mechanisms of polymer-bonded explosives by high resolution moire interferometryand environmental scanning electron microscopy[C]//Paper Summaries-Eleventh International Detonation Symposium. Snowmass, 1998: 235-239. [10] Demol G, Lambert P, Trumel H. A study of the microstructure of pressed TATB and its evolution after several kinds of insults[C]//Paper Summaries-Eleventh International Detonation Symposium. Snowmass, 1998: 404-406. [11] 傅华, 李俊玲, 谭多望.PBX炸药动态Brazilian试验及数值模拟研究[J].高压物理学报, 2012, 26(2):148-154. http://www.cnki.com.cn/Article/CJFDTOTAL-GYWL201202006.htmFu Hua, Li Junling, Tan Duowang. Dynamic Brazilian test and simulation of plastic-bonded explosives[J]. Chinese Journal of High Pressure Physics, 2012, 26(2):148-154. http://www.cnki.com.cn/Article/CJFDTOTAL-GYWL201202006.htm [12] 李俊玲, 傅华, 谭多望, 等.PBX炸药的拉伸断裂损伤分析[J].爆炸与冲击, 2011, 31(6):624-629. doi: 10.11883/1001-1455(2011)06-0624-06Li Junling, Fu Hua, Tan duowang, et al. Fracture damage analysis of PBX[J]. Explosion and Shock Waves, 2011, 31(6):624-629. doi: 10.11883/1001-1455(2011)06-0624-06 [13] 傅华, 刘仓理, 王文强, 等.细观尺度下塑料粘结炸药热点生成的初步模拟研究[J].爆炸与冲击, 2008, 28(6):515-520. doi: 10.3321/j.issn:1001-1455.2008.06.006Fu Hua, Liu Cangli, Wang Wenqiang, et al. Preliminary simulation of hot spot formation for plastic bonded explosives at mesoscale[J]. Explosion and Shock Waves, 2008, 28(6):515-520. doi: 10.3321/j.issn:1001-1455.2008.06.006 -
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