Application of Dang Van criterion to rolling contact fatigue in wind turbine roller bearings under elastohydrodynamic lubrication conditions

Abstract

A 2D plane strain finite element program has been developed to investigate very high cycle fatigue in wind turbine roller bearings due to rolling contact. Focus is on fatigue in the inner ring, where the effect of residual stresses and hardness variation along the depth is accounted for. Both classic Hertzian and elastohydrodynamic lubrication theories have been used to model the pressure distribution acting on the inner raceway and results are compared according to the Dang Van multiaxial fatigue criterion. The contact on the bearing raceway is simulated by substituting the roller with the equivalent contact pressure distribution. The material used for the simulations is taken to be an AISI 52100 bearing steel and linear elastic behavior is here assumed. The effect of different residual stress distributions is also studied, as well as the effect of variable hardness along the depth, relating its values to the fatigue limit parameters for the material. It is found that both for Hertzian and elastohydrodynamic lubrication contacts, the Dang Van criterion predicts that fatigue failure will first occur in the subsurface region and that, regardless of the specific pressure distribution used, the hardness distribution can have a significant influence on the safety against failure for bearings subjected to very high cycle fatigue loading.

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

“…The failure of material point occurs if the load path exceeds the limit state, as depicted in Figure A. Since the effects of significant negative hydrostatic stress are neglected, the original Dang Van criterion is too benevolent to judge the failure of materials. Desimone et al proposed a modified Dang Van criterion, which changes the failure curve to a horizontal straight line when the hydrostatic stress is negative, as shown in Figure B.…”

“…Dang Van criterion takes the current shear stress amplitude τ a ( θ,t ) and current hydrostatic stress σ h ( t ) on one plane at any instant of time t into account: where α is a constant that is determined by where τ −1 is the fatigue limit in reversed torsion and σ −1 is the fatigue limit in pure bending. The ratio of the fatigue limits ( τ −1 / σ −1 ) is usually regarded as an empirical value for fatigue evaluation, lying in the range 0.57 to 0.8 for steels. And the fatigue performances of wind turbine gears and roller bearings have been successfully evaluated with setting the ratio to 0.577.…”

“…The ratio of the fatigue limits ( τ −1 / σ −1 ) is usually regarded as an empirical value for fatigue evaluation, lying in the range 0.57 to 0.8 for steels. And the fatigue performances of wind turbine gears and roller bearings have been successfully evaluated with setting the ratio to 0.577. The ratio in the Dang Van criteria is also set as 0.577 in this study.…”

Evaluation of contact fatigue risk of a carburized gear considering gradients of mechanical properties

“…The fatigue performance of a material can be quantified by the equivalent stress value evaluated by weighted sum of the local maximal shear stress ( max ) and the hydrostatic stress (  h ). The Dang Van equivalent stress can be expressed by [30][31][32]:…”

Simulation of a Steel-Aluminum Composite Material Subjected to Rolling Contact Fatigue

“…where τ O,max is the maximum orthogonal shear stress and the constant k hyd depends on the material properties, which are taken into account. Here, k hyd was calculated in accordance with [21] and had a value of 0.23. According to the Dang Van criterion, the local hydrostatic pressure p hyd was obtained from finite element analysis and was modified by residual stresses.…”