Numerical modeling of projectile penetration into dry sand
-
摘要: 基于砂粒的不可压缩性假设,利用球形空腔动态收缩模型和广义Mises强度准则推导了干砂的孔隙压密演化方程;根据Hugoniot冲击突跃条件和Grüneisen系数,推导了干砂考虑孔隙演化影响的状态方程;根据关联流动法则,得到了大变形时砂的弹塑性应力应变关系;基于动力有限元计算平台,采用上述模型分析了弹体高速侵彻干砂的作用过程。结果表明,该模型能够表征高速侵彻时砂的孔隙演化对应力应变状态的反向影响,能够较准确地反映高速侵彻作用下干砂的动力响应过程。Abstract: Assuming that sand grains are incompressible, a compaction equation for porous dry sand was derived by applying the dynamic systolic model of a spherical cavity and the generalized Mises strength criterion. Based on the Hugoniot jump condition and the Grüneisen parameter, the equation of state for dry sand was given by considering porous compaction. According to the associated flow rule, the elasto-plastic stress-strain relationships of dry sand under large deformation were obtained. By means of the dynamic finite element computing method, the above models were used to analyze the penetration process of dry sand by a projectile. The results show that the models can reflect the reverse influence of sand pore evolution on the stress-strain state in the high-velocity penetration process, and can accurately describe the dynamic response of dry sand under high-velocity penetration.
-
Key words:
- mechanics of explosion /
- porous compaction /
- finite element /
- dry sand /
- high-velocity penetration
-
表 1 砂的侵彻深度计算值与实验结果
Table 1. Test and computed results for penetration depths of sand
m/g vp, 0/(m·s-1) He/m Hc/m $\frac{{\left| {{H_{\text{c}}} - {H_{\text{e}}}} \right|}}{{{H_{\text{s}}}}}$/% 80.30 674 1.37 1.04 24.1 81.20 716 1.28 1.37 7.0 80.96 673 1.33 1.04 21.8 81.05 649 1.26 0.96 23.8 80.86 640 1.27 0.93 26.7 81.11 645 1.26 0.95 24.6 81.15 641 1.28 0.93 27.3 81.00 664 1.24 1.01 18.5 81.25 692 1.36 1.24 8.8 80.75 682 1.29 1.15 10.8 80.42 661 1.30 1.00 23.1 80.30 678 1.37 1.10 19.7 81.10 666 1.47 1.01 31.3 -
[1] Allen W A, Mayfield E B, Morrison H L. Dynamics of a projectile penetration sand[J]. Journal of Applied Physics, 1957, 28(3): 370-376. doi: 10.1063/1.1722750 [2] Allen W A, Mayfield E B, Morrison H L. Dynamics of a projectile penetration sand: Part Ⅱ[J]. Journal of Applied Physics, 1957, 28(11): 1331-1335. doi: 10.1063/1.1722645 [3] Mesri G, Feng T W, Benak J M. Post densification penetration resistance of clean sands[J]. Journal of Geotechnical Engineering, 1990, 116(7): 1095-1115. http://www.nrcresearchpress.com/servlet/linkout?suffix=refg15/ref15&dbid=16&doi=10.1139%2ft11-098&key=10.1061%2f(asce)0733-9410(1990)116%3a7(1095) [4] Goldman D I, Umbanhowar P. Scaling and dynamics of sphere and disk impact into granular media[J]. Physical Review E, 2008, 77(2): 021308. doi: 10.1103/PhysRevE.77.021308 [5] Collins A L, Addiss J W, Walley S M, et al. The effect of nose shape on the internal flow fields during ballistic penetration of sand[J]. International Journal of Impact Engineering, 2011, 38(12): 951-963. doi: 10.1016/j.ijimpeng.2011.08.002 [6] Borg J P, Morrissey M P, Perich C A, et al. In situ velocity and stress characterization of a projectile penetrating a sand target: Experimental measurements and continuum simulations[J]. International Journal of Impact Engineering, 2013, 51(1): 23-35. http://www.sciencedirect.com/science/article/pii/S0734743X12001510 [7] Forrestal M J, Norwood F R, Longcope D B. Penetration into targets described by locked hydrostats and shear strength[J]. International Journal of Solids and Structures, 1981, 17(9): 915-924. doi: 10.1016/0020-7683(81)90106-2 [8] Forrestal M J, Luk V K. Penetration into soil targets[J]. International Journal of Impact Engineering, 1992, 12(3): 427-444. doi: 10.1016/0734-743X(92)90167-R [9] Boguslavskii Y, Drabkin S, Juran I, et al. Theory and practice of projectile's penetration in soils[J]. Journal of Geotechnical Engineering, 1996, 122(10): 806-812. doi: 10.1061/(ASCE)0733-9410(1996)122:10(806) [10] Salgado R, Mitchell J K, Jamiolkowski M. Cavity expansion and penetration resistance in sand[J]. Journal of Geotechnical and Geoenvironmental Engineering, 1997, 123(4): 344-354. doi: 10.1061/(ASCE)1090-0241(1997)123:4(344) [11] Savvateev A F, Budin A V, Kolikov V A, et al. High-speed penetration into sand[J]. International Journal of Impact Engineering, 2001, 26(1/2/3/4/5/6/7/8/9/10): 675-681. http://www.sciencedirect.com/science/article/pii/S0734743X01001324 [12] Kotov V L, Balandin V V, Bragov A M, et al. Using a local interaction model to determine the resistance to penetration of projectiles into sandy soil[J]. Journal of Applied Mechanics and Technical Physics, 2013, 54(4): 612-621. doi: 10.1134/S0021894413040123 [13] Onate E, Rojek J. Combination of discrete element and finite element methods for dynamic analysis of geomechanics problems[J]. Computer Methods in Applied Mechanics and Engineering, 2004, 193(27/28/29): 3087-3128. http://www.sciencedirect.com/science/article/pii/S0045782504001215 [14] Tong X, Tuan C Y. Viscoplastic cap model for soils under high strain rate loading[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2007, 133(2): 206-214. doi: 10.1061/(ASCE)1090-0241(2007)133:2(206) [15] Dwivedi S K, Teeter R D, Felice C W, et al. Two dimensional mesoscale simulations of projectile instability during penetration in dry sand[J]. Journal of Applied Physics, 2008, 104(8): 083502. doi: 10.1063/1.2999391 [16] Kharab A, Hudspeth R T, Guenther R B. Penetration of cylindrical projectiles into saturated sandy media[J]. Experimental Mechanics, 2009, 49(5): 605-612. doi: 10.1007/s11340-008-9190-9 [17] Carroll M M, Holt A C. Static and dynamic porecolapse relations for ductile porous materials[J]. Journal of Applied Physics, 1972, 43(4): 1626-1636. doi: 10.1063/1.1661372 [18] Johnson J N. Dynamic fracture and spallation in ductile solids[J]. Journal of Applied Physics, 1981, 52(4): 2812-2825. doi: 10.1063/1.329011 [19] Leppanen J. Dynamic behaviour of concrete structures subjected to blast and fragment impacts[D]. Sweden: Chalmers University of Technology, 2002: .