Evaluation of Fatigue Crack Propagation of Gears Considering Uncertainties in Loading and Material Properties

Abstract

Failure prediction of wind turbine gearboxes (WTGs) is especially important since the maintenance of these components is not only costly but also causes the longest downtime. One of the most common causes of the premature fault of WTGs is attributed to the fatigue fracture of gear teeth due to fluctuating and cyclic torque, resulting from stochastic wind loading, transmitted to the gearbox. Moreover, the fluctuation of the torque, as well as the inherent uncertainties of the material properties, results in uncertain life prediction for WTGs. It is therefore essential to quantify these uncertainties in the life estimation of gears. In this paper, a framework, constituted by a dynamic model of a one-stage gearbox, a finite element method, and a degradation model for the estimation of fatigue crack propagation in gear, is presented. Torque time history data of a wind turbine rotor was scaled and used to simulate the stochastic characteristic of the loading and uncertainties in the material constants of the degradation model were also quantified. It was demonstrated that uncertainty quantification of load and material constants provides a reasonable estimation of the distribution of the crack length in the gear tooth at any time step.

Description

© 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Keywords

Fatigue, Gear, Crack Propagation, Finite Element Modeling, Uncertainty Quantification, Dynamic Analysis, Wind Turbine Gearbox

Citation

Endeshaw HB, Ekwaro-Osire S, Alemayehu FM, Dias JP. Evaluation of Fatigue Crack Propagation of Gears Considering Uncertainties in Loading and Material Properties. Sustainability. 2017; 9(12):2200. https://doi.org/10.3390/su9122200

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