Shakedown analysis of a wind turbine gear considering strain-hardening and the initial residual stress
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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.
KeywordsGear contact Shakedown state Strain-hardening Initial residual stress
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- H. Haifeng, H. Liu, C. Zhu and Z. P. Wei, Sun study of rolling contact fatigue behavior of a wind turbine gear based on damage–coupled elastic–plastic model, International J. of Mechanical Sciences, 141 (2018) 512–519, https://www. sciencedirect.com/science/article/pii/S0020740318301127.CrossRefGoogle Scholar
- B. D. Allison, Evolution of mechanical properties of M50 bearing steel due to rolling contact fatigue, University of Florida, Florida, United State (2013) 148, https://search. proquest.com/openview/8b0dda537c17a658793f827f029230 34/1?pq–origsite=gscholar&cbl=18750&diss=y.Google Scholar
- Batista,Dias, Lebrun, Flour Le and Inglebert, Contact fatigue of automotive gears: evolution and effects of residual stresses introduced by surface treatments, Fatigue & Fracture of Engineering Materials & Structures, 23 (2000) 217–228, https://onlinelibrary.wiley.com/doi/abs/10.1046/j. 1460–2695.2000.00268.x.Google Scholar
- H. P. Evans, M. F. Al–Mayali and K. J. Sharif, Assessment of the effects of residual stresses on fatigue life of real rough surfaces in lubricated contact, International Conference for Students on Applied Engineering, IEEE, Newcastle upon Tyne, UK (2016) 5, https://ieeexplore.ieee.org/abstract/document/7810173/.Google Scholar
- A. Warhadpande, An elastic–plastic finite element model for rolling contact fatigue, Mechanical Engineering, Purdue University, Indiana, United States (2012) 208, http://appliedmechanics.asmedigitalcollection.asme.org/article.asp x?articleid=1407904.Google Scholar
- Y. Shen, S. M. Moghadam, F. Sadeghi, K. Paulson and R. W. Trice, Effect of retained austenite–Compressive residual stresses on rolling contact fatigue life of carburized AISI 8620 steel, International J. of Fatigue, 75 (2015) 135–144, https://www.sciencedirect.com/science/article/pii/S0142112 315000547.CrossRefGoogle Scholar
- W. Reinhardt and R Adibi–Asl, Non–cyclic shakedownratcheting boundary determination: Analytical examples, Pressure Vessels and Piping Conference, ASME, Washington, USA (2010) 555–563, http://proceedings. asmedigitalcollection.asme.org/proceeding.aspx?articleid=1 618525.Google Scholar
- J. E. Merwin and K. L. Johnson, An analysis of plastic deformation in rolling contact, Proceedings of the Institution of Mechanical Engineers, 1847–1982 (1–196) 177 (1963) 676–690, http://J.s.sagepub.com/doi/abs/10.1243/PIME_ PROC_ 1963_177_052_02.Google Scholar