Roles of microstructure, inclusion, and surface roughness on rolling contact fatigue of a wind turbine gear

Abstract

Contact fatigue is a key feature limiting the service lives and reliabilities of gears. The gear contact fatigue failure mechanism has not been understood fundamentally due to the complexities of structural factors, material properties, and operating conditions. In this work, an integrated finite element model of a megawatt level wind turbine gear is established considering the real gear geometry, material microstructure heterogeneity, existence of nonmetallic inclusion, and the tooth surface roughness. The gear steel material properties are defined based on the crystal elasticity anisotropy framework. The modified Dang Van multiaxial criterion is utilized to estimate the material fatigue failure probability during gear engagement. With the developed model, the roles of microstructure, inclusion, and surface roughness on the gear contact fatigue behaviour are comparatively investigated. Additionally, the influences of different inclusion size and surface roughness profile on gear failure risk are investigated and discussed in detail. K E Y W O R D Scrystal elasticity, inclusion, microstructure, rolling contact fatigue (RCF), surface roughness

Damage behavior due to rolling contact fatigue and bending fatigue of a gear using crystal plasticity modeling

“…The model was able to consider the gear geometry and different loading conditions and achieved good accuracy compared with the finite element analysis. Zhou et al 8 comparatively investigated different roles of the surface roughness and subsurface inclusion on the fatigue performance of gear based on a finite element model. Li et al 9 presented a tribo‐dynamic contact fatigue model by considering the effect of dynamic load conditions.…”

“…The gear contact fatigue failure also occurs at subsurface positions, wherein the material experiences special multiaxial stress-strain history. Up to now, multiaxial fatigue criteria, such as Fatemi-Socie (FS), [13][14][15][16][17][18][19][20][21] Brown-Miller 22 and Dang Van, 8,[23][24][25] have been successfully used in gear contact fatigue studies.…”

Experimental‐based study of gear vibration characteristics incorporating the fractal topography of tooth surface

“…Wang et al 12 proposed a new model for calculating the power loss of planetary gear meshing considering tooth surface roughness and investigated the relationship between tooth surface roughness and the dynamic response. Zhou et al 13 developed a finite element model of a megawatt wind turbine gear and used the developed model to comparatively study the effects of microstructure, inclusions, and surface roughness on the contact fatigue behavior of the gear. Xiao et al 14 proposed a six‐degree‐of‐freedom spur gear transmission system with coated teeth and used the finite element method to obtain the time‐varying meshing stiffness of the coated gear pair during the meshing process.…”

The effect of friction on surface crack initiation in rolling contact fatigue considering damage accumulation

“…Based on CDM theory, Li et al 20 and Guan et al 21 developed the RCF damage evolution models with the explicit finite element analysis. Mostly recently, Wang et al 22 and Zhou et al 23 established a damage‐coupled FEM approach to investigate RCF by considering microstructure and material defects. According to their results, the damage accumulation is accompanied by the complicated variation of stress/strain behavior.…”