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<title>Mitigating stay cable oscillation using semiactive damping</title>

2000; SPIE; Volume: 3988; Linguagem: Inglês

10.1117/12.383142

1996-756X

E. A. Johnson, Greg A. Baker, B. F. Spencer, Yozo Fujino,

Structural Engineering and Vibration Analysis

Stay cables, such as are used in cable-stayed bridges, are prone to vibration due to their low inherent damping characteristics. Transversely-attached passive viscous dampers have been implemented in many bridges to dampen such vibration. Several studies have investigated optimal passive linear viscous dampers, however even the optimal passive device can only add minimal damping to the cable when attached a reasonable distance from the cable deck anchor. This paper investigates the potential for improved damping using semiactive devices. The equations of motion of the cable/damper system are derived using an assumed modes approach and a control-oriented model is developed. The control-oriented model is shown to be more accurate that other models and facilitates low-order control designs. The effectiveness of passive linear viscous dampers are reviewed. The response of a cable with passive, active and semiactive dampers is studied. The response with a semiactive damper is found to be dramatically reduced compared to the optimal passive linear viscous damper for typical damper configurations, thus demonstrating the efficacy of a semiactive damper for absorbing cable vibratory energy.