Solving Stress Intensity Factor of a Non-penetrating Dedendum Crack Using Weight Function Method
-
摘要: 齿轮齿根是具有非穿透性的三维裂纹,其应力强度因子计算求解难度大且过程复杂。对此应用片条合成权函数法将三维裂纹问题转化为一系列“等效的”薄片单元二维裂纹问题。根据作用在薄片单元上的法向力按照其啮合刚度进行分配,求出作用于每个薄片单元上的法向力,再运用二维裂纹权函数法计算每个薄片单元裂纹应力强度因子。其求解结果与有限元法计算结果十分吻合,最大误差为3.9%。Abstract: A gear tooth root has non-penetrating three-dimensional cracks, its stress intensity factor calculation is difficult and the process is complex. In this study, the three-dimensional crack problem is transformed into a series of "equivalent" two-dimensional crack problems of thin section element by using the weight function method of strip composition. According to the normal force acting on tooth root, the normal force acting on each thin section element was calculated based on its meshing stiffness, and then the crack stress intensity factor of each thin section element was calculated by using the two-dimensional crack weight function method. The calculated results of the "equivalent" solution are in good agreement with those of finite element method, and the maximum error is 3.9%.
-
表 1 齿根边缘裂纹权函数的
$ {\beta _i}\left( a \right) $ 系数[12]Table 1. Coefficient of root edge crack weight function [12]
$ a $ $ {\beta _1}\left( a \right) $ $ {\beta _2}\left( a \right) $ $ {\beta _3}\left( a \right) $ $ {\beta _4}\left( a \right) $ 0.01 2.0000 −4.3805 4.7674 −1.6455 0.05 2.0000 −1.5117 4.5540 −1.4116 0.10 2.0000 −0.0074 4.4334 −1.2872 0.20 2.0000 1.8811 2.1992 −0.7144 0.30 2.0000 3.8976 0.9383 −0.3278 0.40 2.0000 5.5887 2.6754 −0.5625 0.50 2.0000 7.8498 4.9653 −0.8697 0.60 2.0000 11.938 7.2380 −1.0518 0.70 2.0000 17.311 15.699 −2.3857 0.80 2.0000 23.436 36.751 −6.1878 0.85 2.0000 30.375 49.189 −8.2129 0.90 2.0000 54.712 60.001 −8.7527 表 2 权函数法与有限元法应力强度因子对比
Table 2. Comparison of stress intensity factors between weight function method and finite element method
轴向单元数 权函数法/
($\rm MPa\cdot {\rm{m}}^{\tfrac{1}{2}} $)有限元法/
($\rm MPa\cdot {\rm{m}}^{\tfrac{1}{2}} $)相对误差/
%1 3.5695 3.7122 −3.9 2 2.9331 2.9785 −2.6 3 2.2405 2.2107 1.3 4 1.2956 1.2626 2.6 5 0.1037 0.1047 1.1 -
[1] ABERŠEK B, FLAŠKER J. Stress intensity factor for cracked gear tooth[J]. Theoretical and Applied Fracture Mechanics, 1994, 20(2): 99-104. doi: 10.1016/0167-8442(94)00004-2 [2] GUAGLIANO M, VERGANI L. Mode I stress intensity factors for curved cracks in gears by a weight functions method[J]. Fatigue & Fracture of Engineering Materials & Structures, 2001, 24(1): 41-52. [3] POPA C O, HARAGÂŞ S. A simulation of the stress intensity factors KI and KII variation in the Hertzian stresses field of gear teeth[J]. Applied Mechanics and Materials, 2016, 823: 17-22. doi: 10.4028/www.scientific.net/AMM.823.17 [4] PEHAN S, HELLEN T K, FLASKER J, et al. Numerical methods for determining stress intensity factors vs crack depth in gear tooth roots[J]. International Journal of Fatigue, 1997, 19(10): 677-685. doi: 10.1016/S0142-1123(97)00101-1 [5] SHAO R P, DONG F F, WANG W, et al. Influence of cracks on dynamic characteristics and stress intensity factor of gears[J]. Engineering Failure Analysis, 2013, 32: 63-80. doi: 10.1016/j.engfailanal.2013.03.008 [6] DONG F F, SHAO R P, MA J. Research on stress intensity factor of gear crack and its variation with changes of gear parameters[J]. Applied Mechanics and Materials, 2011, 121-126: 2211-2217. doi: 10.4028/www.scientific.net/AMM.121-126.2211 [7] 董飞飞, 邵忍平, 王伟. 齿轮参数对三维裂纹应力强度因子影响的研究[J]. 应用力学学报, 2012, 29(6): 723-729.DONG F F, SHAO R P, WANG W. The research on the influence of gear parameters on the stress intensity factors of three-dimensional crack[J]. Chinese Journal of Applied Mechanics, 2012, 29(6): 723-729. (in Chinese) [8] 裴未迟, 楚京, 纪宏超, 等. 基于Abaqus的直齿圆柱齿轮疲劳裂纹应力强度因子研究[J]. 机械传动, 2019, 43(2): 8-12.PEI W C, CHU J, JI H C, et al. Research of stress intensity factor of fatigue crack of spur gear based on Abaqus[J]. Journal of Mechanical Transmission, 2019, 43(2): 8-12. (in Chinese) [9] 杨生华. 采掘机械齿轮轮齿断裂过程仿真与断裂强度[J]. 煤矿机电, 2004(5): 35-38.YANG S H. The fracture process simulation and fracture strength of gear tooth in mining machine[J]. Colliery Mechanical & Electrical Technology, 2004(5): 35-38. (in Chinese) [10] 许德涛, 唐进元, 周炜. 基于扩展有限元法的齿根裂纹扩展规律[J]. 中南大学学报(自然科学版), 2016, 47(8): 2668-2675.XU D T, TANG J Y, ZHOU W. Tooth root crack propagation regularity based on extended finite element method[J]. Journal of Central South University (Science and Technology), 2016, 47(8): 2668-2675. (in Chinese) [11] WU X R, CARLSSON A J. Weight functions and stress intensity factor solutions[M]. Oxford: Pergamon Press, 1991. [12] 于耀庭, 何芝仙, 陈曦. 基于权函数法的齿根裂纹应力强度因子求解[J]. 机械设计, 2020, 37(9): 71-77.YU Y T, HE Z X, CHEN X. Solving the stress intensity factor of cracked dedendum based on the weight function method[J]. Journal of Machine Design, 2020, 37(9): 71-77. (in Chinese) [13] ZHAO W, WU X R, YAN M G. Weight function method for three dimensional crack problems-I basic formulation and application to anembedded elliptical crack in finite plates[J]. Engineering Fracture Mechanics, 1989, 34(3): 593-607. doi: 10.1016/0013-7944(89)90122-7 [14] 于耀庭, 何芝仙, 时培成. 能量法计算齿根具有裂纹的齿轮啮合刚度[J]. 机械科学与技术, 2021, 40(5): 716-720.YU Y T, HE Z X, SHI P C. Calculation of gear mesh stiffness of cracked dedendum via energy method[J]. Mechanical Science and Technology for Aerospace Engineering, 2021, 40(5): 716-720. (in Chinese) [15] 李皓月, 周田鹏, 刘相新. ANSYS工程计算应用教程[M]. 北京: 中国铁道出版社, 2003.LI H Y, ZHOU T P, LIU X X. ANSYS engineering calculation application tutorial[M]. Beijing: China Railway Publishing House, 2003. (in Chinese) [16] 鲁丽君, 李明, 刘建平. 基于ANSYS软件的三维裂纹实体建模方法[J]. 济南大学学报(自然科学版), 2017, 31(4): 292-296.LU L J, LI M, LIU J P. Solid modeling method for three-dimensional crack based on ANSYS software[J]. Journal of University of Jinan (Science and Technology), 2017, 31(4): 292-296. (in Chinese)