Shakedown analysis of a wind turbine gear considering strain-hardening and the initial residual stress

다국어 초록 (Multilingual Abstract)

Under some heavy-duty conditions, the shakedown state may occur on gears such as those used in a megawatt wind turbine gearbox.
The plastic deformation and the residual stress formed within the shakedown process further influence the contact behavior and the service life of the gear. The initial residual stress caused by the heat treatment of the case-hardening gear, together with the strain-hardening constitutive behavior of the material, have a combined effect on the shakedown state. A two-dimensional elastic-plastic contact numerical model was developed for a case-hardened wind turbine gear to study effects of the initial residual stress and the strain-hardening properties. Plastic strain and residual stress are calculated at each loading cycle without the consideration of the tooth friction. The initial yield limit and the hardening modulus of the material were obtained through a tension test on a universal tensile test machine. The initial residual stress distribution was measured with the X ray diffraction method and then embedded in the finite element model. The results show that strain-hardening behavior can significantly improve the shakedown performance, and the larger the hardening modulus is, the less the maximum plastic strain is at the final shakedown state. Initial residual compressive stress is helpful to improve the shakedown performance, while initial residual tensile stress has negative influence on the shakedown performance. As the normal load increases, the influence of the initial residual stress on the shakedown state becomes weakened.

참고문헌 (Reference)

1 E. Conrado, "Use of multiaxial fatigue criteria and shakedown theorems in thermo-elastic rolling–sliding contact problems" 270 : 344-354, 2011

2 A. F. Bower, "The influence of strain hardening on cumulative plastic deformation in rolling and sliding line contact" 37 : 471-493, 1989

3 H. Haifeng, "Sun study of rolling contact fatigue behavior of a wind turbine gear based on damage-coupled elastic-plastic model" 141 : 512-519, 2018

4 N. K. Fukumasu, "Stress analysis to improve pitting resistance in gear teeth" 45 : 255-258, 2016

5 H. Liu, "Starved lubrication of a spur gear pair" 94 : 52-60, 2016

6 P. N. Moulik, "Simulation of thermal stresses due to grinding" 43 : 831-851, 2001

7 R. S. P. Alan, "Shakedown analyses for rolling and sliding contact problems" 43 : 4201-4219, 2006

8 A. W. Aditya, "Rolling contact fatigue of case carburized steels" 95 : 264-281, 2017

9 Nabi Ahmadi, "Predicting the ratcheting strain of 304 stainless steel by considering yield surface distortion and using a viscoplastic model" 대한기계학회 29 (29): 2857-2862, 2015

10 W. Reinhardt, "Non-cyclic shakedownratcheting boundary determination: Analytical examples" ASME 555-563, 2010

11 H. Liu, "Mixed lubricated line contact analysis for spur gears using a deterministic model" 134 : 021501-, 2012

12 B. D. Allison, "Evolution of mechanical properties of M50bearing steel due to rolling contact fatigue" University of Florida 2013

13 H. Liu, "Effects of the case hardening properties on the contact fatigue of a wind turbine gear pair" 141 : 520-527, 2018

14 D. L. Mcdowell, "Effects of non-linear kinematic hardening on plastic deformation and residual stresses in rolling line contact" 144 : 19-37, 1991

15 Y. Shen, "Effect of retained austenite – Compressive residual stresses on rolling contact fatigue life of carburized AISI 8620 steel" 75 : 135-144, 2015

16 A. Kapoor, "Effect of changes in contact geometry on shakedown of surfaces in rolling/sliding contact" 34 : 223-239, 1992

17 Batista, "Contact fatigue of automotive gears: evolution and effects of residual stresses introduced by surface treatments" 23 : 217-228, 2000

18 H. P. Evans, "Assessment of the effects of residual stresses on fatigue life of real rough surfaces in lubricated contact" IEEE, Newcastle upon Tyne 5 : 2016

19 Y. Q. Xu, "Analysis of the gear contact fatigue strength based on the compressive residual stress" 143-144 : 1086-1090, 2010

20 A. Warhadpande, "An elastic-plastic finite element model for rolling contact fatigue" Purdue University 2012

21 J. E. Merwin, "An analysis of plastic deformation in rolling contact" 1847-1982, 1963

22 Yuqin Wen, "A solution considering elastic-plastic deformation of asperities for contact between rough cylindrical surfaces" Emerald 70 (70): 353-362, 2018

23 A. Kapoor, "A shakedown analysis of simple spur gears" 45 : 103-109, 2002

24 K. L. Johnson, "A graphical approach to shakedown in rolling contact" Springer Netherlands 1990