高导无氧铜杆件的颈缩断裂与临界冲击拉伸速度研究
|
摘要
1.一种Hopkinson拉杆试验装置被用于高导无氧铜(OFHC)杆件的冲击拉伸试验:
讨论了拉伸杆件尺度的优化问题并校核了现有的OFHC材料的动态本构关系。对冲击拉伸速度为15.2,16.4和20.1m/s的OFHC拉伸试件进行了回收观测,确定了局部化的断裂应变分别0.99,1.01及1.04。
2.对OFHC试件的Hopkinson拉伸试验进行了数值模拟,并与实验结果比较:
应用LS-DYNA程序,分别采用Johnson-Cook(J-C)本构关系及Zerilli-Armstrong(Z-A)本构关系对OFHC试件的Hopkinson拉伸试验进行了数值模拟,提出了两种关于颈缩与失效的判据,一种基于试件的渐稳动能,另一种基于试件横截面直径的收缩率。
3.采用数值模拟方法研究了OFHC冲击拉伸试件发生颈缩与失效的规律:
考察了试件几何参数及拉伸脉冲对于试件发生颈缩的影响,其中包括试件尺寸及试件初、边值条件对于颈缩位置及颈缩区局部化应变的影响。
4.设计并建立了一种基于一级气体炮的独特的高速拉伸试验装置:
此装置主要由两部分组成,第一部分为气炮系统驱动高速平面飞片,第二部分为平面飞片击靶并牵引多根拉伸试件。
5.采用所建立的高速冲击拉伸试验装置,对OFHC杆件进行了高速拉伸试验:
对OFHC杆件进行了冲击拉伸速度为10.9,19.2,34.0,38和40.6m/s的拉伸试验,确定OFHC的实验临界拉伸速度为40.0m/s,此时颈缩与断裂发生在冲击拉伸端附近,杆件其余部分的延伸率小于5%。
6.讨论了理论临界冲击拉伸速度:
从理论临界拉伸速度的定义出发。采用J-C及Z-A本构关系计算了OFHC材料塑性波趋于零时的不同的临界冲击拉伸速度。
7.提出了一种在临界冲击拉伸速度下计及完全热耦合的一维拉伸杆试验的数值模拟:
在颈缩情况下,计及塑性约束因子、空穴增长与聚集,进行了一维杆拉伸的数值模拟。指出采用Z-A本构关系的数值模拟比较符合实验结果。
1. A Hopkinson bar in tension mode is used in tensile testing for oxygen-free high-conductivity (OFHC) copper bars:
The optimization of specimen dimensions is discussed and the available dynamic constitutive relations for OFHC copper are checked. OFHC copper specimens subjected to tensile velocities of 15.2, 16.4 and 20.1m/s are recovered and the localized fracture strains of 0.99, 1.01 and 1.04 are determined, respectively.
2. The numerical simulations of the necking and failure for OFHC copper bars tested on the Hopkinson bar in tension mode are performed and compared with the experimental results:
The computed results with Johnson-Cook(J-C) and Zerilli-Armstrong(Z-A) constitutive relations in LS-DYNA are compared with the experimental results. The criteria for necking and failure of bars based on the kinetic energy of the specimen and the variation rate of the cross section of the specimen are presented and used in numerical simulation.
3. The regularities of necking and failure for OFHC copper bars under dynamic tension are studied with the numerical simulations:
The effects of specimen geometries and tensile pulse on necking and failure of OFHC copper bars are investigated including the influence of specimen dimensions and initial and boundary conditions on the necking positions and the localized failure strain of bars.
4. A novel facility for high-speed tensile testing is presented based on a single gas gun system:
The facility consists of two assemblies: firstly, a gas gun system to propel the projectile and secondly, the tension mechanism to grip and strain the specimen bars.
5. The critical impact velocity of OFHC copper is determined by using the novel facility for high-speed tensile testing:
OFHC copper specimens subjected to tensile velocities of 10.9, 19.2, 34.0 ,38.0and 40.6m/s are examined. Impacting specimens at higher velocities than 40.0m/s gave fracture consistently at the impact end with 5% ductility across the specimens.
6. The theoretical critical impact velocity in tension is discussed:
For OFHC copper, the theoretical critical impact velocities (the plastic wave speed reaches zero) in tension are calculated with J-C and Z-A constitutive relations and the obvious differents are indicated.
7. A numerical simulation is presented for uniaxial tensile testing at the critical impact velocity in complete thermal coupling:
In case of necking, the plastic constraint factor, the void growth and coalescence are considered. It is indicated that Z-A constitutive relation gave a better prediction of the experimental critical impact velocity in tension for OFHC copper.
讨论了拉伸杆件尺度的优化问题并校核了现有的OFHC材料的动态本构关系。对冲击拉伸速度为15.2,16.4和20.1m/s的OFHC拉伸试件进行了回收观测,确定了局部化的断裂应变分别0.99,1.01及1.04。
2.对OFHC试件的Hopkinson拉伸试验进行了数值模拟,并与实验结果比较:
应用LS-DYNA程序,分别采用Johnson-Cook(J-C)本构关系及Zerilli-Armstrong(Z-A)本构关系对OFHC试件的Hopkinson拉伸试验进行了数值模拟,提出了两种关于颈缩与失效的判据,一种基于试件的渐稳动能,另一种基于试件横截面直径的收缩率。
3.采用数值模拟方法研究了OFHC冲击拉伸试件发生颈缩与失效的规律:
考察了试件几何参数及拉伸脉冲对于试件发生颈缩的影响,其中包括试件尺寸及试件初、边值条件对于颈缩位置及颈缩区局部化应变的影响。
4.设计并建立了一种基于一级气体炮的独特的高速拉伸试验装置:
此装置主要由两部分组成,第一部分为气炮系统驱动高速平面飞片,第二部分为平面飞片击靶并牵引多根拉伸试件。
5.采用所建立的高速冲击拉伸试验装置,对OFHC杆件进行了高速拉伸试验:
对OFHC杆件进行了冲击拉伸速度为10.9,19.2,34.0,38和40.6m/s的拉伸试验,确定OFHC的实验临界拉伸速度为40.0m/s,此时颈缩与断裂发生在冲击拉伸端附近,杆件其余部分的延伸率小于5%。
6.讨论了理论临界冲击拉伸速度:
从理论临界拉伸速度的定义出发。采用J-C及Z-A本构关系计算了OFHC材料塑性波趋于零时的不同的临界冲击拉伸速度。
7.提出了一种在临界冲击拉伸速度下计及完全热耦合的一维拉伸杆试验的数值模拟:
在颈缩情况下,计及塑性约束因子、空穴增长与聚集,进行了一维杆拉伸的数值模拟。指出采用Z-A本构关系的数值模拟比较符合实验结果。
1. A Hopkinson bar in tension mode is used in tensile testing for oxygen-free high-conductivity (OFHC) copper bars:
The optimization of specimen dimensions is discussed and the available dynamic constitutive relations for OFHC copper are checked. OFHC copper specimens subjected to tensile velocities of 15.2, 16.4 and 20.1m/s are recovered and the localized fracture strains of 0.99, 1.01 and 1.04 are determined, respectively.
2. The numerical simulations of the necking and failure for OFHC copper bars tested on the Hopkinson bar in tension mode are performed and compared with the experimental results:
The computed results with Johnson-Cook(J-C) and Zerilli-Armstrong(Z-A) constitutive relations in LS-DYNA are compared with the experimental results. The criteria for necking and failure of bars based on the kinetic energy of the specimen and the variation rate of the cross section of the specimen are presented and used in numerical simulation.
3. The regularities of necking and failure for OFHC copper bars under dynamic tension are studied with the numerical simulations:
The effects of specimen geometries and tensile pulse on necking and failure of OFHC copper bars are investigated including the influence of specimen dimensions and initial and boundary conditions on the necking positions and the localized failure strain of bars.
4. A novel facility for high-speed tensile testing is presented based on a single gas gun system:
The facility consists of two assemblies: firstly, a gas gun system to propel the projectile and secondly, the tension mechanism to grip and strain the specimen bars.
5. The critical impact velocity of OFHC copper is determined by using the novel facility for high-speed tensile testing:
OFHC copper specimens subjected to tensile velocities of 10.9, 19.2, 34.0 ,38.0and 40.6m/s are examined. Impacting specimens at higher velocities than 40.0m/s gave fracture consistently at the impact end with 5% ductility across the specimens.
6. The theoretical critical impact velocity in tension is discussed:
For OFHC copper, the theoretical critical impact velocities (the plastic wave speed reaches zero) in tension are calculated with J-C and Z-A constitutive relations and the obvious differents are indicated.
7. A numerical simulation is presented for uniaxial tensile testing at the critical impact velocity in complete thermal coupling:
In case of necking, the plastic constraint factor, the void growth and coalescence are considered. It is indicated that Z-A constitutive relation gave a better prediction of the experimental critical impact velocity in tension for OFHC copper.
引文
[1] Johnson G.R.,Cook WH. Fracture characteristics of three metals subjected to various strains, strain rates, temperatures and pressures. Eng. Fract. Mech. 1985, 21: 31-48.
[2] Curran DR, Seaman L, Shockey DA. Dynamic failure of solids. Phys. Reports 1987, 147: 253-388.
[3] Ortiz M, Molinari A. Effect of strain hardening and rate sensitivity on the dynamic growth of a void in a plastic material. J. Appl. Mech. 1992, 59: 48-53.
[4] Tong W, Ravichandran G. Inertial effects on void growth in porous viscoplastic materials. J. Appl. Mech. 1995, 62: 633-639.
[5] Wu XY, Ramesh, KT, Wright TW. The dynamic growth of a single void in a viscoplastic material under transient hydyostatic loading. J. Mech. Phys. Solids 2003, 51: 1-26.
[6] Pardoen T, Hutchinson JW. An extended model for void growth and coalescence. J. Mech. Phys. Solids 2000, 48: 2467-2512.
[7] Gologanu M, Leblond JB, Devaux J. Approximate models for ductile metals containing nonspherical void -case of axisymmetric prolate ellipsoidal cavities. J. Mech. Phys. Solids 1993, 41: 1723-1754.
[8] Benzerga AA. Micromechanics of coalescence in ductile fracture. J. Mech. Phys. Solids 2002, 50: 1331-1362.
[9] Ragab AR. Prediction of ductile fracture in axisymmetric tension by void coalescence. Int. J. Fract. 2000; 105:391-409.
[10] Gao X, Faleskog J, Shih CF. Cell model for nonlinear fracture analysis—Ⅱ. Fracture-process calibration and verification. Int. J. Fracture 1998, 89: 374-386.
[11] Ragab A R, Saleh Ch, Zaafarani NN. Forming limit diagrams for kinematically hardened voided sheet metals. J. Mater. Processing Technol. 2002, 128:302-312.
[12] Ragab AR. Application of an extended void growth model with strain hardening and void shape evolution to ductile fracture under axisymmetric tension. Eng. Fract. Mech. 2004, 71: 1515-1534.
[13] Ragab AR. A model for ductile fracture based on internal necking of spheroidal voids. Acta. Mater. 2004, 52:3997-4009.
[14] Barton DC. Determination of the high strain rate fracture properties of ductile materials using a combined experimental/numerical approach. Int. J. Impact Eng. 2004, 30: 1147-1159.
[15] Sturges JL, Cole BN. The flying wedge: a method for high strain rate tensile testing. Part 1. Reasons for its development and general description. Int. J. Impact Eng. 2001, 25: 251-264.
[16] Chen Danian,Yu YuYing,Yin Zhihua,Wang Huanran, Liu Guoqing, Xie Shugang, A modified Cochran-Banner spall model. Int. J. Impact Eng. 2005, 31: 1106-1118.
[17] Chen Danian, Tan Hua, Yu Yuying, Wang Huanran, Xie Shugang, Liu Guoqing, Yin Zhihua, A void coalescence-based spall mode. Int. J. Impact Eng. 2006, 32:1752-1767.
[18] Chen Danian, Fan Chunlei, Xie Shugang, Hu Jinwei, Wu Shanxing, Wang huanran. Study on constitutive relations and spall models for oxygen-free high-conductivity copper under planar shock tests. J. Appl. Phys. 2007, 101:063532.
[19]陈大年,尹志华.对膨胀壳体材料失稳的一种简化处理.爆炸与冲击,1999,19:193-198.
[20] S.T.S. Al-Hassani, Danian Chen. A Simplified approach to materials instab-ility under high strain rate stretching Key Eng. Mat.2000,117-180:393-400.
[21] Considere M. L’Emplor du fer et Lacier Dans Les Constructions. Ann Des Ponts et Chausses,Ⅸ(6 eme serie),1985,9:574.
[22] Hart EW. Theory of the tensile tests. Acta. Metall, 1967, 15:351.
[23] Duncombe E. Analysis of diffuse plastic stability in tubes and sheets. Int. J. Solids Struct., 1974, 10: 1445.
[24] Ghosh AK. Tensile instability and necking in materials with strain hardening and strain rate hardening. Acta Metall, 1977, 25: 1413.
[25] Gotoh M, Yamashita M, Chaotic behavior of an elastoplastic bar in tensile test over a wide range of strain rate: a numerical investigation. Int. J. Mech. Sciences, 2000, 42: 1593-1606.
[26] Rusinek A, Zaera R, Klepaczko J.R, Cheriguene R. Analysis of inertia and scale effects on dynamic neck formation during tension of sheet steel. Acta. Mater., 2005, 53: 5387-5400.
[27] Karman T. On the propagation of plastic deformation in solids. NDRC Report No. A-29, February 2, 1942.
[28] Taylor GI. Plastic wave in wire extended by an impact load. Scientific papers, Vol. 1 mechanics of solids. Cambridge: Cambridge University Press;1958, P:456.
[29] Karman T, Duwez P, The propagation of plastic deformation in solids. J. Appl. Phys. 1950, 21:987.
[30] Duwez PE, Clark DS. An experimental study of the propagation of plastic deformation under conditions of longitudinal impact. Proc ASTM, 1947, 47:502.
[31] Clark DS, Wood DS. The influence of specimen dimension and shape on the results in tension impact testing. Proc ASTM, 1950, 50:577.
[32] Wood WW. Experimental mechanics at velocity extremes—very high strain rates. Experimental Mechanics, 1967, 10: 441.
[33] Klepaczko JR. Review on critical impact velocities in tension and shear. Int. J. Impact Eng. 2005, 32:188-209.
[34] Hu JW, Jin YH, Chen DN, Wu SX, Wang HR, Ma DF. Measurement of critical impact velocity of copper in tension. Chin Phys Lett 2008, 25: 1049-1051.
[35]陈大年,胡金伟,金扬辉,吴善幸,王焕然,马东方.高导无氧铜临界冲击拉伸速度的实验与数值研究.爆炸与冲击(录用待发).
[36] Johnson G R and Cook W H. A constitutive model and data for metals subjected to large strains, high strain-rates and high temperatures, Porc. Seventh Int. Nat. Symposium on Ballistcs, April 1983.
[37] Zerilli F J and Armstrong R W. Dislocation-mechanics-based constitutive relations for material dynamics calculations. J. Appl. Phys. 1987, 61: 1816.
[38] J.O.Hallquist,April 2003.LS-DYNA Keywords Use’s Manual(970v).L.S.T.C USA.
[39] W. K. Rule, S. E. Jones. A revised form for the Johnson-Cook strength model. Int. J. Impact Eng. 1998, 21: 609-624.
[40] G. R. Johnson, T. J. Holmquist. Evaluation of cylinder-impact test data for constitutive model constants. J. Appl. Phys. 1988, 64: 3901-3910
[41] O. Oussouaddi, J. R. Klepaczko. An analysis of transition between isothermal and adiabatic deformation for the case of torsion of a tube. Supplement an Journal de PhysiqueⅢ. 1991, 1: 323.
[42] Bridgman,P.W.,Studies in large plastic flow and fracture.New York:McGraw-Hill Book Company,1952.
[43] A. L. Gurson. Continuum theory of ductile rupture by void nucleation and growth, Part I -Yield criteria and flow rules for porous ductile media. J. Eng. Mater. Technol. 1977, 99: 2-15.
[44] P. F. Thomason. A three-dimensional model for ductile fracture by the growth and coalescence of microvoids. Acta Metallurgica. 1985, 33: 1087-1095.
[2] Curran DR, Seaman L, Shockey DA. Dynamic failure of solids. Phys. Reports 1987, 147: 253-388.
[3] Ortiz M, Molinari A. Effect of strain hardening and rate sensitivity on the dynamic growth of a void in a plastic material. J. Appl. Mech. 1992, 59: 48-53.
[4] Tong W, Ravichandran G. Inertial effects on void growth in porous viscoplastic materials. J. Appl. Mech. 1995, 62: 633-639.
[5] Wu XY, Ramesh, KT, Wright TW. The dynamic growth of a single void in a viscoplastic material under transient hydyostatic loading. J. Mech. Phys. Solids 2003, 51: 1-26.
[6] Pardoen T, Hutchinson JW. An extended model for void growth and coalescence. J. Mech. Phys. Solids 2000, 48: 2467-2512.
[7] Gologanu M, Leblond JB, Devaux J. Approximate models for ductile metals containing nonspherical void -case of axisymmetric prolate ellipsoidal cavities. J. Mech. Phys. Solids 1993, 41: 1723-1754.
[8] Benzerga AA. Micromechanics of coalescence in ductile fracture. J. Mech. Phys. Solids 2002, 50: 1331-1362.
[9] Ragab AR. Prediction of ductile fracture in axisymmetric tension by void coalescence. Int. J. Fract. 2000; 105:391-409.
[10] Gao X, Faleskog J, Shih CF. Cell model for nonlinear fracture analysis—Ⅱ. Fracture-process calibration and verification. Int. J. Fracture 1998, 89: 374-386.
[11] Ragab A R, Saleh Ch, Zaafarani NN. Forming limit diagrams for kinematically hardened voided sheet metals. J. Mater. Processing Technol. 2002, 128:302-312.
[12] Ragab AR. Application of an extended void growth model with strain hardening and void shape evolution to ductile fracture under axisymmetric tension. Eng. Fract. Mech. 2004, 71: 1515-1534.
[13] Ragab AR. A model for ductile fracture based on internal necking of spheroidal voids. Acta. Mater. 2004, 52:3997-4009.
[14] Barton DC. Determination of the high strain rate fracture properties of ductile materials using a combined experimental/numerical approach. Int. J. Impact Eng. 2004, 30: 1147-1159.
[15] Sturges JL, Cole BN. The flying wedge: a method for high strain rate tensile testing. Part 1. Reasons for its development and general description. Int. J. Impact Eng. 2001, 25: 251-264.
[16] Chen Danian,Yu YuYing,Yin Zhihua,Wang Huanran, Liu Guoqing, Xie Shugang, A modified Cochran-Banner spall model. Int. J. Impact Eng. 2005, 31: 1106-1118.
[17] Chen Danian, Tan Hua, Yu Yuying, Wang Huanran, Xie Shugang, Liu Guoqing, Yin Zhihua, A void coalescence-based spall mode. Int. J. Impact Eng. 2006, 32:1752-1767.
[18] Chen Danian, Fan Chunlei, Xie Shugang, Hu Jinwei, Wu Shanxing, Wang huanran. Study on constitutive relations and spall models for oxygen-free high-conductivity copper under planar shock tests. J. Appl. Phys. 2007, 101:063532.
[19]陈大年,尹志华.对膨胀壳体材料失稳的一种简化处理.爆炸与冲击,1999,19:193-198.
[20] S.T.S. Al-Hassani, Danian Chen. A Simplified approach to materials instab-ility under high strain rate stretching Key Eng. Mat.2000,117-180:393-400.
[21] Considere M. L’Emplor du fer et Lacier Dans Les Constructions. Ann Des Ponts et Chausses,Ⅸ(6 eme serie),1985,9:574.
[22] Hart EW. Theory of the tensile tests. Acta. Metall, 1967, 15:351.
[23] Duncombe E. Analysis of diffuse plastic stability in tubes and sheets. Int. J. Solids Struct., 1974, 10: 1445.
[24] Ghosh AK. Tensile instability and necking in materials with strain hardening and strain rate hardening. Acta Metall, 1977, 25: 1413.
[25] Gotoh M, Yamashita M, Chaotic behavior of an elastoplastic bar in tensile test over a wide range of strain rate: a numerical investigation. Int. J. Mech. Sciences, 2000, 42: 1593-1606.
[26] Rusinek A, Zaera R, Klepaczko J.R, Cheriguene R. Analysis of inertia and scale effects on dynamic neck formation during tension of sheet steel. Acta. Mater., 2005, 53: 5387-5400.
[27] Karman T. On the propagation of plastic deformation in solids. NDRC Report No. A-29, February 2, 1942.
[28] Taylor GI. Plastic wave in wire extended by an impact load. Scientific papers, Vol. 1 mechanics of solids. Cambridge: Cambridge University Press;1958, P:456.
[29] Karman T, Duwez P, The propagation of plastic deformation in solids. J. Appl. Phys. 1950, 21:987.
[30] Duwez PE, Clark DS. An experimental study of the propagation of plastic deformation under conditions of longitudinal impact. Proc ASTM, 1947, 47:502.
[31] Clark DS, Wood DS. The influence of specimen dimension and shape on the results in tension impact testing. Proc ASTM, 1950, 50:577.
[32] Wood WW. Experimental mechanics at velocity extremes—very high strain rates. Experimental Mechanics, 1967, 10: 441.
[33] Klepaczko JR. Review on critical impact velocities in tension and shear. Int. J. Impact Eng. 2005, 32:188-209.
[34] Hu JW, Jin YH, Chen DN, Wu SX, Wang HR, Ma DF. Measurement of critical impact velocity of copper in tension. Chin Phys Lett 2008, 25: 1049-1051.
[35]陈大年,胡金伟,金扬辉,吴善幸,王焕然,马东方.高导无氧铜临界冲击拉伸速度的实验与数值研究.爆炸与冲击(录用待发).
[36] Johnson G R and Cook W H. A constitutive model and data for metals subjected to large strains, high strain-rates and high temperatures, Porc. Seventh Int. Nat. Symposium on Ballistcs, April 1983.
[37] Zerilli F J and Armstrong R W. Dislocation-mechanics-based constitutive relations for material dynamics calculations. J. Appl. Phys. 1987, 61: 1816.
[38] J.O.Hallquist,April 2003.LS-DYNA Keywords Use’s Manual(970v).L.S.T.C USA.
[39] W. K. Rule, S. E. Jones. A revised form for the Johnson-Cook strength model. Int. J. Impact Eng. 1998, 21: 609-624.
[40] G. R. Johnson, T. J. Holmquist. Evaluation of cylinder-impact test data for constitutive model constants. J. Appl. Phys. 1988, 64: 3901-3910
[41] O. Oussouaddi, J. R. Klepaczko. An analysis of transition between isothermal and adiabatic deformation for the case of torsion of a tube. Supplement an Journal de PhysiqueⅢ. 1991, 1: 323.
[42] Bridgman,P.W.,Studies in large plastic flow and fracture.New York:McGraw-Hill Book Company,1952.
[43] A. L. Gurson. Continuum theory of ductile rupture by void nucleation and growth, Part I -Yield criteria and flow rules for porous ductile media. J. Eng. Mater. Technol. 1977, 99: 2-15.
[44] P. F. Thomason. A three-dimensional model for ductile fracture by the growth and coalescence of microvoids. Acta Metallurgica. 1985, 33: 1087-1095.