Effect of loading rate on the mode<b>Ⅱ</b> dynamic fracture characteristics of 40Cr steel

FAN Changzeng; XU Zejian; HE Xiaodong; HUANG Fenglei

doi:10.11883/bzycj-2021-0029

Volume 41 Issue 8

Aug. 2021

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FAN Changzeng, XU Zejian, HE Xiaodong, HUANG Fenglei. Effect of loading rate on the modeⅡ dynamic fracture characteristics of 40Cr steel[J]. Explosion And Shock Waves, 2021, 41(8): 083101. doi: 10.11883/bzycj-2021-0029

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FAN Changzeng, XU Zejian, HE Xiaodong, HUANG Fenglei. Effect of loading rate on the modeⅡ dynamic fracture characteristics of 40Cr steel[J]. Explosion And Shock Waves, 2021, 41(8): 083101. doi: 10.11883/bzycj-2021-0029

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Effect of loading rate on the modeⅡ dynamic fracture characteristics of 40Cr steel

doi: 10.11883/bzycj-2021-0029

State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081， China

Received Date: 2021-01-21
Rev Recd Date: 2021-04-21

Available Online: 2021-07-20

Publish Date: 2021-08-05

Abstract

Abstract

40Cr high strength steel is often used in aerospace and national defense fields due to its excellent mechanical properties. Therefore, the research on the mode Ⅱ dynamic fracture characteristics and failure mechanism of 40Cr high strength steel under high-speed impact has important scientific significance and engineering value. Experiments and numerical simulations were carried out to study the mode Ⅱ dynamic fracture properties of 40Cr material under high loading rates. Based on the newly designed specimen and the novel test technique for mode Ⅱ dynamic fracture, the experimental-numerical method was used to determine the dynamic stress intensity factor curve of the crack tip during the loading process. The crack initiation time of the specimen was obtained by the strain gauge pasted on the specimen, and the mode Ⅱ dynamic fracture toughness of 40Cr was finally determined. The effect of loading rate and the failure mechanism of the material were also studied. The results show that within the present loading rate range of this work (1.08−5.53 TPa·m^1/2/s), the mode Ⅱ dynamic fracture toughness of 40Cr presents a positive correlation with the loading rate. Through the analysis of the fracture morphology of the recovered specimen, it is found that there exists a transition from tensile failure mode to adiabatic shear failure mode with the increase of loading rate, and the critical loading rate is about 2.92 TPa·m^1/2/s. When K_Ⅱd≤1.70 TPa·m^1/2/s, the 40Cr steel mainly exhibits brittle fracture; when K_Ⅱd is in the range of 2.12−2.92 TPa·m^1/2/s, the fracture mainly presents the morphological characteristics of ductile fracture; when K_Ⅱd ≥ 3.19 TPa·m^1/2/s, the material failure is mainly caused by adiabatic shear bands. Brittle fracture is dominated by strain rate hardening mechanism, ductile fracture is dominated by strain/strain rate hardening and thermal softening mechanisms, and adiabatic shear fracture is dominated by thermal softening mechanism.
- high strength steel,
- loading rate,
- mode Ⅱ dynamic fracture toughness,
- failure mode transition

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References(27)

References

[1]	黄浩. 40Cr表面激光熔覆硬质涂层及其应用研究[D]. 河北秦皇岛: 燕山大学, 2016.
[2]	KALTHOFF J F. Shadow optical analysis of dynamic shear fracture [J]. Optical Engineering, 1988, 27(10): 271035. DOI: 10.1117/12.7976772.
[3]	KALTHOFF J F. Transition in the failure behavior of dynamically shear loaded cracks [J]. Applied Mechanics Reviews, 1990, 43(S5): 47–50. DOI: 10.1115/1.3120818.
[4]	KALTHOFF J F. Modes of dynamic shear failure in solids [J]. International Journal of Fracture, 2000, 101(1): 1–31. DOI: 10.1023/A: 1007647800529.
[5]	KALTHOFF J F, BÜRGEL A. Influence of loading rate on shear fracture toughness for failure mode transition [J]. International Journal of Impact Engineering, 2004, 30(8): 957–971. DOI: 10.1016/j.ijimpeng.2004.05.004.
[6]	ZHOU M, ROSAKIS A J, RAVICHANDRAN G. Dynamically propagating shear bands in impact-loaded prenotched plates—Ⅰ. experimental investigations of temperature signatures and propagation speed [J]. Journal of the Mechanics and Physics of Solids, 1996, 44(6): 981–1006. DOI: 10.1016/0022-5096(96)00003-8.
[7]	ZHOU M, RAVICHANDRAN G, ROSAKIS A J. Dynamically propagating shear bands in impact-loaded prenotched plates—Ⅱ. numerical simulations [J]. Journal of the Mechanics and Physics of Solids, 1996, 44(6): 1007–1021, 1023-1032. DOI: 10.1016/0022-5096(96)00004-X.
[8]	ZHOU M, ROSAKIS A J, RAVICHANDRAN G. On the growth of shear bands and failure-mode transition in prenotched plates: a comparison of singly and doubly notched specimens [J]. International Journal of Plasticity, 1998, 14(4): 435–451. DOI: 10.1016/S0749-6419(98)00003-5.
[9]	RAVI-CHANDAR K. On the failure mode transitions in polycarbonate under dynamic mixed-mode loading [J]. International Journal of Solids and Structures, 1995, 32(6): 925–938. DOI: 10.1016/0020-7683(94)00169-W.
[10]	RAVI-CHANDAR K, LU J, YANG B, et al. Failure mode transitions in polymers under high strain rate loading [J]. International Journal of Fracture, 2000, 101(1): 33–72. DOI: 10.1023/A: 1007581101315.
[11]	MASON J J, ROSAKIS A J, RAVICHANDRAN G. On the strain and strain rate dependence of the fraction of plastic work converted to heat: an experimental study using high speed infrared detectors and the Kolsky bar [J]. Mechanics of Materials, 1994, 17(2): 135–145. DOI: 10.1016/0167-6636(94)90054-X.
[12]	CHU D Y, LI X, LIU Z L, et al. A unified phase field damage model for modeling the brittle-ductile dynamic failure mode transition in metals [J]. Engineering Fracture Mechanics, 2019, 212: 197–209. DOI: 10.1016/j.engfracmech.2019.03.031.
[13]	CHIANG F. Moiré and speckle methods applied to elastic-plastic fracture studies[C]//Experimental Techniques in Fracture Mechanics. New York: VCH, 1993: 291-325.
[14]	SANFORD R J. Determining fracture parameters with full-field optical methods [J]. Experimental Mechanics, 1989, 29(3): 241–247. DOI: 10.1007/BF02321401.
[15]	PATTERSON E A, OLDEN E J. Optical analysis of crack tip stress fields: a comparative study [J]. Fatigue & Fracture of Engineering Materials & Structures, 2004, 27(7): 623–635. DOI: 10.1111/j.1460-2695.2004.00774.X.
[16]	MA L, KOBAYASHI A S, ATLURI S N, et al. Crack linkup: an experimental analysis [J]. Experimental Mechanics, 2002, 42(2): 147–152. DOI: 10.1007/BF02410876.
[17]	GOECKE K E, MOSHIER M A. A technique to measure fatigue crack growth threshold [J]. Experimental Mechanics, 2002, 42(2): 182–185. DOI: 10.1007/BF02410881.
[18]	王洪山. 几种实用的断裂试验方法 [J]. 理化检验-物理分册, 2001, 37(7): 292–294. DOI: 10.3969/j.issn.1001-4012.2001.07.005. WANG H S. Some kinds of practical fracture test methods [J]. Physical Testing and Chemical Analysis Part A: Physical Testing, 2001, 37(7): 292–294. DOI: 10.3969/j.issn.1001-4012.2001.07.005.
[19]	姜风春, 刘瑞堂. 动态断裂韧性测试方法的有效性分析 [J]. 哈尔滨工程大学学报, 1999, 20(3): 97–101. DOI: 10.3969/j.issn.1006-7043.1999.03.017. JIANG F C, LIU R T. Analysis of validity of dynamic fracture toughness measurement [J]. Journal of Harbin Engineering University, 1999, 20(3): 97–101. DOI: 10.3969/j.issn.1006-7043.1999.03.017.
[20]	郑坚, 王泽平, 段祝平. 动态断裂的加载和测试技术 [J]. 力学进展, 1994, 24(4): 459–475. DOI: 10.6052/1000-0992-1994-4-j1994-042. ZHENG J, WANG Z P, DUAN Z P. Loading and measuring techniques indynamic fracture testing [J]. Advances in Mechanics, 1994, 24(4): 459–475. DOI: 10.6052/1000-0992-1994-4-j1994-042.
[21]	许泽建, 李玉龙, 刘元镛, 等. 两种高强钢在高加载速率下的Ⅱ型动态断裂韧性 [J]. 金属学报, 2006, 42(6): 635–640. DOI: 10.3321/j.issn: 0412-1961.2006.06.013. XU Z J, LI Y L, LIU Y Y, et al. Mode Ⅱ dynamic fracture toughness of two high strength steels under high loading rate [J]. Acta Metallurgica Sinica, 2006, 42(6): 635–640. DOI: 10.3321/j.issn: 0412-1961.2006.06.013.
[22]	许泽建, 黄风雷, 何晓东. 一种用于纯Ⅱ型动态断裂的试验件: CN201820669843.4 [P]. 2018-12-11.
[23]	XU Z J, HE X D, HAN Y, et al. A different viewpoint on mechanism of fracture to shear-banding failure mode transition [J]. Journal of the Mechanics and Physics of Solids, 2020, 145: 104165. DOI: 10.1016/j.jmps.2020.104165.
[24]	XU Z J, HAN Y, FAN C Z, et al. Dynamic shear fracture toughness and failure characteristics of Ti-6Al-4V alloy under high loading rates [J]. Mechanics of Materials, 2021, 154: 103718. DOI: 10.1016/j.mechmat.2020.103718.
[25]	JIANG F C, VECCHIO K S. Hopkinson bar loaded fracture experimental technique: a critical review of dynamic fracture toughness tests [J]. Applied Mechanics Reviews, 2009, 62(6): 060802. DOI: 10.1115/1.3124647.
[26]	BAI Y L, DODD B. Adiabatic shear localization: occurrence, theories, and applications [M]. Oxford: Pergamon Press, 1992: 73−75.
[27]	NEMAT-NASSER S, ISAACS J B, STARRETT J E. Hopkinson techniques for dynamic recovery experiments [J]. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1991, 435(1894): 371–379. DOI: 10.1098/rspa.1991.0150.