Innovative Mobile TMD System for Semi-active Vibration Control of Inclined Sagged Cables

Abstract

In this study an innovative mobile Tuned Mass Damper (TMD) system is proposed which enables the TMD device to move along the cable and optimize its position. A three dimensional model of an inclined cable with sag is created using OpenSees. A mobile TMD device incorporating a semi-active Magnetorheological (MR) damper is implemented. Nine different control strategies, including six fuzzy strategies as well as a continuous sky-hook, an on-off sky-hook, and a passive-on strategy, are employed for the purpose of vibration mitigation. A locating algorithm is also devised so as to optimize the TMD position. A specific load pattern containing a chirp signal is utilized with the purpose of performing the nonlinear time history analyses. The results investigate the efficiency of different control systems in a comparative manner. The effect of locating algorithm is also examined. The results claim that although the suggested control systems can effectively reduce the displacements of the cable, they are relatively incompetent to make a remarkable reduction in maximum and normed values of the cable tension. The output data certify the significant contribution of LA for promoting the performance of control systems. This algorithm especially influences the reduction of normed values of displacement. In general, the fuzzy control algorithms show a much higher performance compared with the passive-on and sky-hook counterparts.