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Computational analysis of gear-box roller-bearing white-etch cracking: A multi-physics approach

M. Grujicic (Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA)
V. Chenna (Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA)
R. Galgalikar (Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA)
J.S. Snipes (Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA)
S. Ramaswami (Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA)
R. Yavari (Department of Mechanical Engineering, Clemson University, Clemson, South Carolina, USA)

International Journal of Structural Integrity

ISSN: 1757-9864

Article publication date: 11 November 2014

Abstract

Purpose

A simple economic analysis has revealed that in order for wind energy to be a viable alternative, wind-turbines (convertors of wind energy into electrical energy) must be able to operate for at least 20 years, with only regular maintenance. However, wind-turbines built nowadays do not generally possess this level of reliability and durability. Specifically, due to the malfunction and failure of drive-trains/gear-boxes, many wind-turbines require major repairs after only three to five years in service. The paper aims to discuss these issues.

Design/methodology/approach

The subject of the present work is the so-called white etch cracking, one of the key processes responsible for the premature failure of gear-box roller-bearings. To address this problem, a multi-physics computational methodology is developed and used to analyze the problem of wind-turbine gear-box roller-bearing premature-failure. The main components of the proposed methodology include the analyses of: first, hydrogen dissolution and the accompanying grain-boundary embrittlement phenomena; second, hydrogen diffusion from the crack-wake into the adjacent unfractured material; third, the inter-granular fracture processes; and fourth, the kinematic and structural response of the bearing under service-loading conditions.

Findings

The results obtained clearly revealed the operation of the white-etch cracking phenomenon in wind-turbine gear-box roller-bearings and its dependence on the attendant loading and environmental conditions.

Originality/value

The present work attempts to make a contribution to the resolution of an important problem related to premature-failure and inferior reliability of wind-turbine gearboxes.

Keywords

Citation

Grujicic, M., Chenna, V., Galgalikar, R., Snipes, J.S., Ramaswami, S. and Yavari, R. (2014), "Computational analysis of gear-box roller-bearing white-etch cracking: A multi-physics approach ", International Journal of Structural Integrity, Vol. 5 No. 4, pp. 290-327. https://doi.org/10.1108/IJSI-10-2013-0028

Publisher

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Emerald Group Publishing Limited

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