Long‐term contact fatigue analysis of a planetary bearing in a land‐based wind turbine drivetrain

Abstract

This paper presents an approach for performing a long-term fatigue analysis of rolling element bearings in wind turbine gearboxes. Multilevel integrated analyses were performed using the aeroservoelastic code HAWC2, the multibody dynamics code SIMPACK, the three-dimensional finite element code Calyx and a simplified lifetime prediction model for rolling contact fatigue. The National Renewable Energy Laboratory's 750 kW wind turbine and its planetary bearing were studied. Design load cases, including normal production, parked and transient load cases, were considered. To obtain the internal bearing load distribution, an advanced approach combining a finite element/contact mechanics model and a response surface model were used. In addition, a traditional approach, the Harris model, was also applied for comparison. The long-term probability distribution of the bearing raceway contact pressure range was then obtained using Weibull and generalized Gamma distribution functions. Finally, we estimated the fatigue life of the bearing, discussed the differences of the methods used to obtain the bearing internal loads and analyzed the effects of the environmental conditions and load cases on the results. The Harris model may underestimate the inner raceway life by 55.7%, which can cause large load fluctuations along the raceways. The bearing fatigue life is very sensitive to the wind distribution and less affected by the transient and parked load cases.

Structural Reliability Analysis of Wind Turbines: A Review

“…Such an approach often relies on measurement or test data and lacks insight into the physical nature of structural degradation and failure. To evaluate the drivetrain design loads and understand the load effects in operational, parked or fault conditions of onshore wind turbines, various studies on dynamic response analysis [53,[117][118][119][120][121][122] have been carried out using finite element or multibody simulation codes. For example, Dong et al [119] performed dynamic response analysis of a 750-kW wind turbine drivetrain and analyzed the dynamic gear contact forces.…”

“…For example, Dong et al [119] performed dynamic response analysis of a 750-kW wind turbine drivetrain and analyzed the dynamic gear contact forces. Jiang et al [53] also performed multibody simulation of the same drivetrain and focused on the dynamic loads on the planetary bearings. Zhao and Ji [123] proposed a four-degree-of-freedom dynamic model and studied the dynamic responses of both the gears and bearings of a wind turbine gearbox.…”

A prognostic method for fault detection in wind turbine drivetrains

“…Based on the Harris elastic deformation model of rolling bearings [34], the clearance affects the load distribution factor and consequently the forcedeflection relationship and the bearing stiffness. More information about bearing load analysis can be found in Jiang et al [35].…”

Assessment of wind turbine drive-train fatigue loads under torsional excitation

“…When using a cluster, with multiple CPUs within a node, the computation expense is approximately 1.2 times with and without external drive-train. One of the main conclusions from [17] was the relevance of fatigue studies for normal operation load cases. Therefore, having a fast tool such as the one presented on this paper is a clear advantage.…”