Parameter Identification of Long Stroke and Short Stroke MR Damper for its Use in Semi-Active Vibration Control

Abstract

Magnetorheological (MR) dampers are devices that can be used for structural vibration reduction under seismic excitation. These devices are used in semi-active control which require less power compared to active devices and offer high reliability compared to passive devices. Despite the advantages of MR damper, use of these dampers in an effective way in a structure is highly challenging and a precise modelling is required as these dampers are highly non-linear. Among the parametric models available, Bouc–Wen model is widely used because of its effective modelling of the hysteretic force–velocity curve of MR damper. The parameters of Bouc–Wen model are damper dependent and hence need to be identified before utilising the damper for further simulation studies. In this work, the parametric identification of Bouc–Wen model for commercially available long stroke and short stroke MR damper (RD 8040-1 and RD 8041-1) is done. For this, experimental characterization of the dampers are carried out using hydraulic actuators mounted on a self-restraining frame. The damper is driven harmonically in the testing setup at various combinations of frequency, amplitude, current and displacement. Using the experimental characterization, parameters of Bouc–Wen model are identified by Levenberg–Marquardt optimization Algorithm (LMA). The identified parameters are validated by comparing with the experimental results. The identified parameters are believed to be worthwhile for the use of these MR dampers in further studies of real-time semi-active vibration control of structures.