Investigation on dynamic coupling between stay cable and magnetorheological fluid (MR) damper

In this paper, experimental investigation on vibration control is carried out on a stay cable model incorporated with one small size magnetorheological fluid (MR) damper. The control efficiency of the MR dampers to reduce the cable vibration under sinusoidal excitation using passive control strategy is firstly tested. The dynamic coupling between the cable and MR damper with the passive control strategy is obviously observed. Dynamic coupling models between stay cable and MR damper with constant and fluctuating current input are proposed respectively. The proposed dynamic coupling model corresponding to the MR damper with constant current input is validated by the numerical simulations of the measured experimental data. Furthermore, using the proposed dynamic coupling corresponding to the MR damper with fluctuating current input, experimental investigation on the cable vibration control subjected to sinusoidal excitation using semi-active control strategy is then conducted. Experimental results demonstrate that the semi-active MR damper can achieve much better mitigation efficacy than the passive MR dampers with different constant current inputs due to negative stiffness provided by the semi-active MR damper.