Investigation of locking force for stay cable vibration control using magnetorheological fluid damper

The locking force of stay cable vibration control using a magnetorheological (MR) fluid damper is investigated in this paper. For a single mode vibration of a stay cable equipped with a MR damper, the locking force formula is derived and the important factors that affect the locking force are analyzed. The experimental investigations of the locking force of the stay cable vibration control are carried out on a cable-stayed bridge model equipped with a MR damper to verify the computational locking force. For the multimode vibration of the stay cable, the modal shapes of the stay cable vibration are estimated by utilizing a pole placement observer using the acceleration values at selected locations of the stay cable, and the locking forces of the stay cable in multimode vibration are numerically obtained. In all experimental cases, the locking forces based on the analytical and numerical formulas approximately match the experimental results.