Abstract
Abstract. Vibration damper is widely used in overhead transmission lines to alleviate aeolian vibration. Its natural frequencies are important parameters for a vibration damper. In this paper, the approximate calculation formulas of natural frequencies of the one-side subsystem of a Stockbridge type vibration damper were derived and the design sensitivity analysis of the natural frequencies was studied using partial differential equations with respect to each concerned parameter including the length of the steel strand, the mass of the counterweight, the eccentric distance, and the radius of gyration of the counterweight. Through a case study that considered a variation of up to ±30 % in the values of the design parameters, the exact calculation and approximate calculation results of the natural frequencies were analysed, and the sensitivity of the vibration damper's natural frequencies to the design parameters was studied. The results show that, within the range of the parameters used in this study, the approximately calculated first-order frequency is lower than the exact values, whereas the approximately calculated second-order frequency is larger than the exact values. The sensitivity analysis indicates that the first-order frequency is highly sensitive to the steel strand's length, whereas it is moderately sensitive to the counterweight's mass and slightly sensitive to the eccentric distance and the gyration radius of the counterweight; the second-order frequency is highly sensitive to the steel strand's length and the gyration radius of the counterweight, moderately sensitive to the counterweight's mass, and slightly sensitive to the eccentric distance. It will provide theoretical guidance and approximate analysis method in engineering for the design of the vibration damper.
Highlights
The first-order frequency obtained by approximate calculation is lower than exact calculation results, whereas the second-order frequency obtained by approximate calculation is larger than exact calculation results
Similar to the variations of parameters m and L, the first-order frequency obtained by approximate calculation is lower than exact calculation results, whereas the second-order frequency obtained by approximate calculation is larger than the exact calculation results (Fig. 4e)
When parameter R changes within the range of ±30 %, the first-order frequency obtained by approximate calculation is lower than the exact calculation results, whereas the second-order frequency obtained by approximate calculation is larger than exact calculation results (Fig. 4g)
Summary
When the natural wind blows over the overhead transmission lines, the transmission lines vibrate due to the effect of Kármán vortex street (Dutkiewicz and Machado, 2019), and it is called aeolian vibration of the transmission lines (Barry et al, 2012; Foti and Martinelli, 2018; Dutkiewicz and Machado, 2019; Si et al, 2020). To reduce the vibration amplitude to the allowable fatigue limit line, some protective devices have been developed and used in the transmission lines Among these devices, a Stockbridge type vibration damper, which was invented by Stockbridge (1928), is widely used for its wide range of frequencies (Bukhari and Barry, 2018; Bukhari et al, 2018; Foti and Martinelli, 2018; Barbieri et al, 2019). The approximate calculation formulas of natural frequencies of the one-side subsystem of a Stockbridge type vibration damper were derived, and the design sensitivity analysis of the natural frequencies was studied using partial differential equations with respect to each concerned structure design parameter. This study can provide theoretical guidance and approximate analysis method in engineering for the design of the vibration damper
Sign-in/Register to view highlights & summary 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.
