Title: Time-varying stiffness analysis on rotating shaft with elliptical-front crack

Authors: Xiaopeng Wei; Dajun Liu; Lasheng Zhao; Qiang Zhang

Addresses: Key Laboratory of Advanced Design and Intelligent Computing, Dalian University, Ministry of Education, Dalian, 116622, China ' Key Laboratory of Advanced Design and Intelligent Computing, Dalian University, Ministry of Education, Dalian, 116622, China ' Key Laboratory of Advanced Design and Intelligent Computing, Dalian University, Ministry of Education, Dalian, 116622, China ' Key Laboratory of Advanced Design and Intelligent Computing, Dalian University, Ministry of Education, Dalian, 116622, China

Abstract: The aim of this paper is to investigate the difference of time-varying stiffness characteristics between a semi-elliptical front crack and a straight front crack of shaft-element in order to obtain a more accurate and realistic cracked-rotor model for rotating machinery system. By calculating the correct time-varying area moments of inertia for the cross-section of cracked element and taking account the neutral axis position changes, the switching function is obtained, meanwhile the stiffness of shaft in a steady rotating cycle is determined. The result shows that a significant difference of stiffness appears as crack depth deepens. Especially, the difference between elliptical-front (EF) and straight-front (SF) cracked element is more obvious in the early crack propagation.

Keywords: time-varying stiffness; semi-elliptical front crack; straight front crack; rotating shafts; switching function; rotating machinery; shaft cracks; shaft cracking; modelling; crack propagation.

DOI: 10.1504/IJISE.2014.062540

International Journal of Industrial and Systems Engineering, 2014 Vol.17 No.3, pp.302 - 314

Published online: 25 Jul 2014 *

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