Vibration Reduction Performance of an Active Damping Control System for a Scaled System of a Cable-Stayed Bridge

Abstract

The main objective of this work is to develop an active damping system that can be used to reduce the vibrations of cables in stayed bridges. As a first stage, a laboratory physical scale model of a prestressed cable was used to characterize and test the dynamic performance of the damping system that comprises accelerometers to measure cable vibrations, an electromagnetic actuator which interacts with the cable to compensate for externally induced vibrations, and a digital controller in which control strategies and algorithms are defined. In the experiment, an additional actuator was used to excite vibration disturbances on the cable modifying its frequency and amplitude, and the location for the accelerometers was defined from simulations with a linear model of the cable to optimize the damping control method. Two different system identification approaches were used to calculate the frequency response function of the whole system (cable, accelerometers and actuators); the first approach used the spectral analysis to get initial dynamic results of the cable system, while the second employed the parametric identification to obtain the transfer function of the system, by which different models were assessed. Model reduction techniques and the direct synthesis approach were selected to get a second-order model for the controller. The active damping system was first evaluated with simulation studies and then, in the laboratory. Results show that the damping system reduces the vibration amplitude up to 50% for the resonance frequency. Complementary simulations using a full scale cable model of the stayed bridge with an equivalent active damping system, showed the same damping efficiency as for that in the laboratory experiment; however, a practical application must consider the scaling factor and the limitations of possible locations and orientations of the damping actuator to get the best dynamic performance.

Investigation of modal damping ratios for stay cables based on stochastic subspace identification with ambient vibration measurements

“…By further investigation, it was also discovered that the modal damping of stay cable may increase with increasing vibration amplitude (Li et al, 2015; Qiu and Maji, 2014; Shen et al, 2016) or with increasing cable sag (Shen et al, 2016). Along with the rapid progress in constructing more and more cable-stayed bridges, numerous types of supplementary devices such as viscous damper (Zhou et al, 2014), high damping rubber damper (Cu et al, 2015), fluid damper (Xu and Zhou, 2007), tuned-mass damper (Hijmissen et al, 2009), Coulomb friction damper (Weber et al, 2010), magnetorheological damper (Weber and Distl, 2015) and active damper (Cárdenas et al, 2015) have been developed and applied to improve the vibration stability of stay cable by enhancing its damping. Again, an effective design for either of the abovementioned artificial dampers strongly depends on accurate modal damping ratios of the cable.…”

Accurate Dynamic Responses Analysis of Orthotropic Steel Decks Using a Novel Multiscale Time-Varying Boundary Approximation Method

“…Combining aesthetic features with e±cient applications of structural materials, longspan cable-stayed bridges have been extensively used in railway bridge engineering over the past few decades. [1][2][3] However, due to the weak adaptability of unballasted tracks to the deformation of integral bridge deck systems, ballast tracks are more widely used for increasing span lengths. [4][5][6] Correspondingly, integral bridge decks have fully replaced traditional open bridge decks as the main type of°oor system in these long-span bridges.…”