Dynamic stability of rotating blades with transverse cracks

Article type: Research Article

Authors: Ng, T.Y.^; | Lam, K.Y. | Li, Hua

Affiliations: Institute of High Performance Computing, 1 Science Park Road, #01-01 The Capricorn Singapore Science Park II, Singapore 117528 | School of Mechanical and Production Engineering, Nanyang Technological University 50 Nanyang Avenue, Singapore 639798

Note: [] Corresponding author. E-mail: mtyng@ntu.edu.sg

Abstract: In this paper, the main objective is to examine the effects of transverse cracks on the dynamic instability regions of an axially loaded rotating blade. The blade is modeled as an Euler-Bernoulli beam. To reduce the governing equations to a set of ordinary differential equations in matrix form, Hamilton's principle is used in conjunction with the assumed-mode method. The crack is accounted for by considering the energy release rate and the parametric instability regions are obtained using Bolotin's first approximation. Benchmark results are presented for cracked rotating blades at different rotating speeds, crack lengths and crack positions.

Keywords: rotating blade, transverse crack, dynamic stability, parametric resonance, Hamilton's principle, assumed-mode method, Bolotin's first approximation

Journal: Shock and Vibration, vol. 10, no. 3, pp. 187-194, 2003