Study on Opening and Closing Phenomenon of Fretting Crack on Fastening Surface of Diesel Engine Block
-
摘要: 柴油机机体材料ZL702A铝合金的微动疲劳实验中，裂纹形核于接触后缘，且在拉应力下裂纹处于闭合状态，在压应力下裂纹处于张开状态。本文针对该特殊的开闭机制采用有限元进行分析。首先利用累计耗散能的概念确定了裂纹萌生的位置，运用SWT参数法和MTS准则法模拟得到的裂纹拓展路径，与实验对比发现MTS准则可以较为准确地模拟裂纹纹路径；其次运用MTS准则模拟裂纹拓展时，测量了裂纹表面的法向应力与切向应力，得出这种特殊的裂纹的开闭现象是由微动接触引起裂纹表面一侧变形造成的；最后，引入裂纹张开度参数RCOD与有效应力强度因子对Paris公式进行修正，得出具有裂纹开闭现象的微动疲劳寿命方程，对比之下发现：不考虑裂纹开闭的疲劳寿命预测值明显高于实验值，而考虑裂纹开闭的疲劳寿命预测值则与实验值一致性较好。Abstract: The fretting fatigue test of ZL702A aluminum alloy shows that the crack nucleates at the contact trailing edge, and it is closed under tensile stress and open under compressive stress. The finite element method is used to analyze the special opening and closing mechanism. Firstly, the concept of cumulative dissipation energy is used to determine the location of crack initiation. In the simulation of crack propagation path with Smith-watson-topper (SWT) parameter method and Max Tangential Stress (MTS) criterion method, MTS criterion can accurately simulate the crack pattern path comparing with the experiment. Secondly, when MTS criterion is used to simulate crack growth, the normal stress and tangential stress on the crack surface are measured, and the special crack opening is obtained. The closing phenomenon is caused by the deformation of one side of the crack surface caused by fretting contact. Finally, the ratio of crack opening dependency (RCOD) and the effective stress intensity factor are introduced to modify Paris formula, and the fretting fatigue life equation with crack opening and closing phenomenon is obtained. By comparison, it is found that the prediction value of fatigue life without considering crack opening and closing is significantly higher than the test value, while the fatigue life with considering crack opening and closing is significantly higher than the test value. The life prediction value is in a good agreement with the test value.
-
Key words:
- fretting fatigue /
- crack propagation /
- aluminum alloy /
- finite element method
-
表 2 不同轴向载荷下的微动疲劳实验寿命
编号 夹紧力/kN 轴向载荷/MPa 平均寿命/次 1 2 69 132 793 2 2 88 103 091 3 2 104 74 149 4 2 121 36 352 5 2 138 15 182 6 2 156 784 
下载: 导出CSV
-
[1] 李杰.机体螺栓连接件接触面间微动疲劳寿命预测方法研究[D].太原: 中北大学, 2019LI J. The research on prediction method of fretting fatigue life between the contact surface of the body bolt connector[D]. Taiyuan: North University of China, 2019 (in Chinese) [2] SU Y, HAN Q N, QIU W H, et al. High temperature in-situ SEM observation and crystal plasticity simulation on fretting fatigue of Ni-based single crystal superalloys[J]. International Journal of Plasticity, 2020, 127:102645 doi: 10.1016/j.ijplas.2019.102645 [3] MUTOH Y, XU J Q. Fracture mechanics approach to fretting fatigue and problems to be solved[J]. Tribology International, 2003, 36(2):99-107 doi: 10.1016/S0301-679X(02)00136-6 [4] NORAPHAIPHIPAKSA N, MANONUKUL A, KANCHANOMAI C, et al. Fretting fatigue life prediction of 316L stainless steel based on elastic-plastic fracture mechanics approach[J]. Tribology International, 2014, 78:84-93 doi: 10.1016/j.triboint.2014.04.029 [5] SALIMI-MAJD D, SHAHABI F, MOHAMMADI B. Effective local stress intensity factor criterion for prediction of crack growth trajectory under mixed mode fracture conditions[J]. Theoretical and Applied Fracture Mechanics, 2016, 85:207-216 doi: 10.1016/j.tafmec.2016.01.009 [6] 蔡强.柴油机铝合金机体紧固面微动疲劳寿命预测方法研究[D].太原: 中北大学, 2017CAI Q. The research on f retting fatigue life prediction method of diesel engine aluminum alloy block fastening surface[D]. Taiyuan: North University of China, 2017 (in Chinese) [7] RAMAN S D S, PADMANABHAN K A. Determination of the room-temperature cyclic stress-strain curve of AISI 304LN austenitic stainless steel by two different methods[J]. International Journal of Fatigue, 1992, 14(5):295-304 doi: 10.1016/0142-1123(92)90480-Z [8] ASTM. ASTM E647-11 Standard test method for measurement of fatigue crack growth rates[S]. American: American Society of Testing Materials, 2011 [9] ATZORI B, CAMPAGNOLO A, RICOTTA M, et al. Analysis and comparison of some LEFM parameters[J]. Procedia Structural Integrity, 2019, 18:413-421 doi: 10.1016/j.prostr.2019.08.183 [10] NAVARRO C, VáZQUEZ J, DOMíNGUEZ J. 3D vs. 2D fatigue crack initiation and propagation in notched plates[J]. International Journal of Fatigue, 2014, 58:40-46 doi: 10.1016/j.ijfatigue.2013.02.024 [11] MOHRBACHER H, CELIS J P, ROOS J R. Laboratory testing of displacement and load induced fretting[J]. Tribology International, 1995, 28(5):269-278 doi: 10.1016/0301-679X(95)00005-O [12] ZHANG H Y, LIU J X, ZUO Z X. Investigation into the effects of tangential force on fretting fatigue based on XFEM[J]. Tribology International, 2016, 99:23-28 doi: 10.1016/j.triboint.2016.03.003 [13] TAYLOR D. The theory of critical distances: a new perspective in fracture mechanics[M]. Amsterdam, UK: Elsevier, 2007 [14] MANGARDICH D, ABRARI F, FAWAZ Z. A fracture mechanics based approach for the fretting fatigue of aircraft engine fan dovetail attachments[J]. International Journal of Fatigue, 2019, 129:105213 doi: 10.1016/j.ijfatigue.2019.105213 [15] SATO A, HIRAKAWA Y, SUGAWARA K. Analysis of mechanical and hydraulic properties of cracked structure by the ratio of crack opening dependency (RCOD)[J]. Elsevier Geo-Engineering Book Series, 2004, 2:541-546 [16] 尚德广.疲劳强度理论[M].北京:科学出版社, 2017SHANG D G. Fatigue strength theory[M]. Beijing: Science Press, 2017 (in Chinese) -
点击查看大图
图(15) / 表(2)
计量
- 文章访问数: 88
- HTML全文浏览量: 53
- PDF下载量: 16
- 被引次数: 0
