Abstract
The efficiency and reliability of the bulb turbine can be influenced by the crack fault of the blade in the actual hydropower engineering. To explore this problem, this work is employed to mainly study the effects of the crack fault on the dynamic characteristics of the blade under different external excitations. Firstly, a displacement function of the cracked blade is innovatively proposed as the sum of a polynomial admissible function and a supplementary admissible function reflecting crack characteristics. Then, employing this displacement function, the natural frequency and mode function of the cracked blade can be calculated by Ritz method. Moreover, based on the derived mode function, the dynamical differential equation of the cracked blade can also be obtained. Finally, the truncation sensitivity of the displacement function is discussed, and by comparing with the finite element method, the reliability of the crack model is also verified. Meanwhile, the dynamic characteristics of the blade are studied with the changing of the excitation amplitude and frequency under different crack depth. Fortunately, the detailed dynamic evolutions of the blade and the effects of the crack depth on that are gotten. More importantly, these results can guide the operation of the hydropower station and provide a new method for the identification of the blade crack.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
