A novel technique for determining the dynamic Bauschinger effect by electromagnetic Hopkinson bar

DU Bing; GUO Yazhou; LI Yulong

doi:10.11883/bzycj-2020-0050

Volume 40 Issue 8

Aug. 2020

Turn off MathJax

Article Contents

Article Navigation > Explosion And Shock Waves > 2020 > 40(8): 081101

DU Bing, GUO Yazhou, LI Yulong. A novel technique for determining the dynamic Bauschinger effect by electromagnetic Hopkinson bar[J]. Explosion And Shock Waves, 2020, 40(8): 081101. doi: 10.11883/bzycj-2020-0050

Citation:

DU Bing, GUO Yazhou, LI Yulong. A novel technique for determining the dynamic Bauschinger effect by electromagnetic Hopkinson bar[J]. Explosion And Shock Waves, 2020, 40(8): 081101. doi: 10.11883/bzycj-2020-0050

Citation:

PDF( 1809 KB)

A novel technique for determining the dynamic Bauschinger effect by electromagnetic Hopkinson bar

doi: 10.11883/bzycj-2020-0050

School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, Shaanxi, China

Received Date: 2020-02-28
Rev Recd Date: 2020-05-21

Available Online: 2020-07-25

Publish Date: 2020-08-01

Abstract

Abstract

Dynamic mechanical behavior of metallic materials under complicated loading conditions has attracted much attention. However, it is hard to obtain the dynamic Bauschinger effect of metallic materials due to the limitation of loading equipment. In order to investigate the relationship between the Bauschinger effect and strain rate effect of metallic materials, this paper proposes an asynchronous loading technique based on electromagnetic split Hopkinson bar system, which could provide an effective way to study the Bauschinger effect of metallic materials under high strain rate loading. We first introduce the main characteristics of the asynchronous loading device, that is, the specimen can be loaded by one cycle of continuous dynamic tension-compression loading pulse in which the two separate stress waves are created by electromagnetic pulse generators and prove to maintain their consistency. The propagation of stress waves was analyzed to ensure the continuity of the loading process. Then the dynamic loading process and the methods of data processing and stress wave separation are presented. Stress equilibrium was also analyzed in order to demonstrate the reliability of the equipment. Finally, the Bauschinger effect of 6061 aluminum alloy at 5% pre-strain during the process of dynamic compression to dynamic tension loading was studied using this method, and the corresponding quasi-static tests were also conducted for comparison. It was found that the material shows less strain-rate sensitivity under axial compression loading, while its Bauschinger stress parameter increases from 0.07 in quasi-static loading to 0.17 in dynamic loading. The results indicate that the Bauschinger effect of 6061 aluminum alloys depends on the strain rate and can be significantly enhanced under dynamic loading. This conclusion presents a challenge to the traditional conception that aluminum alloys are insensitive to strain rate.
- electromagneticsplitHopkinsonbar,
- asynchronous loading,
- continuous loading,
- Bauschinger effect,
- high strain rate

FullText(HTML)

References(22)

References

[1]	BAUSCHINGER J. Changes of the elastic limit and the modulus of elasticity on various metals [J]. Zivilingenieur, 1881, 27: 289–348.
[2]	STOLTZ R E, PELLOUX R M. The Bauschinger effect in precipitation strengthened aluminum alloys [J]. Metallurgical Transactions A, 1976, 7(8): 1295–1306. DOI: 10.1007/BF02658814.
[3]	STOUT M G, ROLLETT A D. Large-strain Bauschinger effects in fcc metals and alloys [J]. Metallurgical Transactions A, 1990, 21(12): 3201. DOI: 10.1007/BF02647315.
[4]	FREDERICK C O, ARMSTRONG P J. A mathematical representation of the multiaxial Bauschinger effect [J]. Materials at High Temperatures, 2007, 24(1): 1–26. DOI: 10.3184/096034007X207589.
[5]	BUCKLEY S N, ENTWISTLE K M. The Bauschinger effect in super-pure aluminum single crystals and polycrystals [J]. Acta Metallurgica, 1956, 4(4): 352–361. DOI: 10.1016/0001-6160(56)90023-2.
[6]	ATKINSON J D, BROWN L M, STOBBS W M. The work-hardening of copper-silica: IV: the Bauschinger effect and plastic relaxation [J]. Philosophical Magazine, 1974, 30(6): 1247–1280. DOI: 10.1080/14786437408207280.
[7]	MOAN G D, EMBURY J D. Study of the Bauschinger effect in Al-Cu alloys [J]. Acta Metallurgica, 1979, 27(5): 903–914. DOI: 10.1016/0001-6160(79)90125-1.
[8]	HIDAYETOGLU T K, PICA P N, HAWORTH W L. Aging dependence of the Bauschinger effect in aluminum alloy 2024 [J]. Materials Science and Engineering, 1985, 73: 65–76. DOI: 10.1016/0025-5416(85)90296-4.
[9]	唐长国, 朱金华, 周惠久. 金属材料屈服强度的应变率效应和热激活理论 [J]. 金属学报, 1995, 31(6): 248–253. DOI: 10.1007/BF02943514. TANG C G, ZHU J H, ZHOU H J. Correlation between yield stress and strain rate for metallic materials and thermal activation approach [J]. Acta Metallrugica Sinica, 1995, 31(6): 248–253. DOI: 10.1007/BF02943514.
[10]	HOPKINSON B. X A method of measuring the pressure produced in the detonation of high, explosives or by the impact of bullets [J]. Philosophical Transactions of the Royal Society of London: Series A: containing Papers of a Mathematical or Physical Character, 1914, 213(497-508): 437–456. DOI: 10.1098/rsta.1914.0010.
[11]	MIAO Y, DU B, SHEIKH M Z. On measuring the dynamic elastic modulus for metallic materials using stress wave loading techniques [J]. Archive of Applied Mechanics, 2018, 88(11): 1953–1964. DOI: 10.1007/s00419-018-1422-6.
[12]	MIAO Y, DU B, MA C, et al. Some fundamental problems concerning the measurement accuracy of the Hopkinson tension bar technique [J]. Measurement Science and Technology, 2019, 30(5): 055009. DOI: 10.1088/1361-6501/ab01b5.
[13]	胡时胜, 王礼立, 宋力, 等. Hopkinson压杆技术在中国的发展回顾 [J]. 爆炸与冲击, 2014, 34(6): 4–20. DOI: 10.11883/1001-1455(2014)06-0641-17. HU S S, WANG L L, SONG L, et al. Review of the development of Hopkinson pressure bar technique in China [J]. Explosion and Shock Wave, 2014, 34(6): 4–20. DOI: 10.11883/1001-1455(2014)06-0641-17.
[14]	李玉龙, 索涛, 郭伟国, 等. 确定材料在高温高应变率下动态性能的Hopkinson杆系统 [J]. 爆炸与冲击, 2005, 25(6): 487–492. DOI: 10.11883/1001-1455(2005)06-0487-06. LI Y L, SUO T, GUO W G, et al. Determination of dynamic behavior of materials at elevated temperatures and high strain rates using Hopkinson bar [J]. Explosion and Shock Waves, 2005, 25(6): 487–492. DOI: 10.11883/1001-1455(2005)06-0487-06.
[15]	李玉龙, 郭伟国. 微型 Hopkinson 杆技术 [J]. 爆炸与冲击, 2006, 26(4): 303–308. DOI: 10.11883/1001-1455(2006)04-0303-06. LI Y L, GUO W G. Miniature-Hopkinson bar technique [J]. Explosion and Shock Waves, 2006, 26(4): 303–308. DOI: 10.11883/1001-1455(2006)04-0303-06.
[16]	果春焕, 周培俊, 陆子川, 等. 波形整形技术在Hopkinson杆实验中的应用 [J]. 爆炸与冲击, 2015, 35(6): 881–887. DOI: 10.11883/1001-1455(2015)06-0881-07. GUO C H, ZHOU P J, LU Z C, et al. Application of pulse shaping technique in Hopkinson bar experiments [J]. Explosion and Shock Waves, 2015, 35(6): 881–887. DOI: 10.11883/1001-1455(2015)06-0881-07.
[17]	THAKUR A, NEMAT-NASSER S, VECCHIO K S. Dynamic Bauschinger effect [J]. Acta materialia, 1996, 44(7): 2797–2807. DOI: 10.1016/1359-6454(95)00385-1.
[18]	NIE H, SUO T, WU B, et al. A versatile split Hopkinson pressure bar using electromagnetic loading [J]. International Journal of Impact Engineering, 2018, 116: 94–104. DOI: 10.1016/j.ijimpeng.2018.02.002.
[19]	苗应刚, 李玉龙, 邓琼, 等. Investigation on experimental method of low-impedance materials using modified Hopkinson pressure bar [J]. Journal of Beijing Institute of Technology, 2015, 24(2): 269–276. DOI: 10.15918/j.jbit1004-0579.201524.0220. MIAO Y G, LI Y L, DENG Q, et al. Investigation on experimental method of low-impedance materials using modified Hopkinson pressure bar [J]. Journal of Beijing Institute of Technology, 2015, 24(2): 269–276. DOI: 10.15918/j.jbit1004-0579.201524.0220.
[20]	NIE H, SUO T, SHI X, et al. Symmetric split Hopkinson compression and tension tests using synchronized electromagnetic stress pulse generators [J]. International Journal of Impact Engineering, 2018, 122: 73–82. DOI: 10.1016/j.ijimpeng.2018.08.004.
[21]	RAVICHANDRAN G, SUBHASH G. Critical appraisal of limiting strain rates for compression testing of ceramics in a split Hopkinson pressure bar [J]. Journal of the American Ceramic Society, 1994, 77(1): 263–267. DOI: 10.1111/j.1151-2916.1994.tb06987.x.
[22]	FAN X, SUO T, SUN Q, et al. Dynamic mechanical behavior of 6061 Al alloy at elevated temperatures and different strain rates [J]. Acta Mechanica Solida Sinica, 2013, 26(2): 111–120. DOI: 10.1016/S0894-9166(13)60011-7.