Development of Cable-Exciting System for Evaluating Modal Damping of Stay Cables

Abstract

One of the effective alternatives to suppress hazardous vibration of stay cables is to use cable dampers. In order to design the cable damper optimally, it is necessary to exactly estimate the dynamic characteristics of existing cables. To estimate more reliable dynamic properties of stay cables, precise excitations inducing forced vibration are needed. Hence, in this paper, a cable-exciting system (cable exciter) controlled digitally is developed. A design formula for the cable exciter is also derived by the solution of the equation of motion of a cable-exciter system. The performance of the cable exciter is verified by sine sweeping tests and resonance tests for a cable model in a laboratory. Also from those tests, more reliable dynamic properties of the cable model are obtained. Thus, it is ascertained that modal damping of stay cables is proportional to the amplitude of cable vibration.

Keywords

Stay cables cable-exciting system modal damping resonance test

Get full access to this article

View all access options for this article.

References

Ahn, S. S. , 2002, “Design of elasto-plastic damper for stay cables,” Korean Society of Civil Engineers 22(6-A), 1401-1410 (in Korean).

Ahn, S. S. and Lee, I. K. , 2000, “Study on devices for suppressing vibration of bridges,” Report No. HRC 00-30, Korea Highway Corporation (in Korean).

Bournand, Y. , 1999, “Development of new stay cable dampers,” in Proceedings of IABSE Conference, Malmo, Sweden, June.

Claren, R. and Diana, G. , 1969, “Mathematical analysis of transmission line vibration,” IEEE Transactions on Power Apparatus and Systems 88, 1741-1771 .

Clough, R. W. and Penzien, J. , 1993, Dynamics of Structures, McGraw-Hill, Singapore .

Fang, J. and Lyons, G. J. , 1996, “Structural damping of tensioned pipes with reference to cables,” Journal of Sound and Vibration 193(4), 891-907 .

Fuzier, J. and Stubler, J. , 1998, “Wind vibrations and damping systems for stay cables,” in Long-Span and High-Rise Structures, IABSE Symposium, Kobe, Japan, pp. 205-210 .

Gimsing, N. J. , 1983, Cable Supported Bridges, Wiley, Norwich .

Hard, A. R. and Holben, R. O. , 1967, “Application of the vibration decay test to transmission line conductors,” IEEE Transactions on Power Apparatus and Systems 86, 189-199 .

10.

Hjorth-Hansen, E. , Strommen, E. , Myrvoll, F. , Hansvold, C. , and Ronnebrant, R. , 2001, “Performance of a friction damping device for the cables on Uddevalla cable-stayed bridge,” in Proceedings of 4th International Symposium on Cable Dynamics, AIM, Liege, Belgium, pp. 179-186 .

11.

Irvine, M. , 1981, Cable Structures, Dover, NY .

12.

Kim, N. S. and Jeong, W. , 2002, “Evaluation of tension force of stay cables using vibration method,” Transactions of the Korean Society for Noise and Vibration Engineering 12(12), 956-963 (in Korean).

13.

Nakamura, A. , Kasuga, A. , and Arai, H. , 1998, “The effects of mechanical dampers on stay cables with high-damping rubber,” Construction and Building Material 12(2-3), 115-123 .

14.

Pacheco, B. M. , Fujino, Y. , and Sulekh, A. , 1993, “Estimation curve for modal damping in stay cables with viscous damper,” ASCE Journal of Structural Engineering 12(2-3), 1961-1979 .

15.

Ramberg, S. E. and Griffin, O. M. , 1977, “Free vibration of taut and slack marine cables,” ASCE Journal of the Structures Division 103, 2079-2092 .

16.

Raoof, M. and Huang, Y. P. , 1991, “Upper-bound prediction of cable damping under cyclic bending,” ASCE Journal of Engineering Mechanics 117(12), 2729-2747 .

17.

Seo, J. W. , Kim, N. S. , Ha, D. H. , and Suh, J. I. , 2002, “Development of cable damper with high damping rubber bearing for cable-stayed bridge,” in Proceedings of the 5th European Conference on Structural Dynamics, EURODYN2002, Munich, Germany, September, pp. 217-221 .

18.

Seppa, T. O. , 1971, “Self-damping measurements and energy balance of ACSR Drake,” in Institute of Electronics Engineers Winter Power Meeting, New York, Conference Paper 71 CP 161-PWR.

19.

Tabatabai, H. and Mehrabi, A. B. , 2000, “Design of mechanical viscous dampers for stay cables,” ASCE Journal of Bridge Engineering 5(2), 114-123 .

20.

Takano, H. , Ogasawara, M. , Ito, N. , Shimosato, T. , Takeda, K. , and Murakami, T. , 1997, “Vibrational damper for cables of the Tsurumi Tsubasa bridge,” Journal of Wind Engineering and Industrial Aerodynamics 6971, 807-818 .

21.

Xu, Y. L. and Yu, Z. , 1998, “Mitigation of three-dimensional vibration of inclined Sab cable using discrete oil dampers - II. Application,” Journal of Sound and Vibration 214(4), 675-693 .

22.

Yamaguchi, H. and Adhikari, R. , 1995, “Energy-based evaluation of modal damping in structural cables with and without damping treatment,” Journal of Sound and Vibration 181(1), 71-83 .

23.

Yu, A. T. , 1952, “Vibration damping of stranded cable,” Proceedings of the Society for Experimental Stress Analysis 9, 141-158 .

24.

Yu, Z. and Xu, Y. L. , 1998, “Mitigation of three-dimensional vibration of inclined Sab cable using discrete oil dampers-I. formulation,” Journal of Sound and Vibration 214(4), 659-673 .