Earthquake reduction behaviors of viscous fluid dampers for soil-eccentric structure interaction system

Using the Lagrange energy method, the dynamic equations of the soil - eccentric structure interaction system is established. By applying the linear quadratic regulator (LQR) control theory, the calculated control gain is converted to the equivalent viscous fluid damping gain using a minimum norm method (MNM). In the case of including the soil-structure interaction into consideration, the translational and torsional responses of single-story asymmetric buildings installed with the VFDs under unidirectional earthquakes is investigated. Simultaneously, the effects of the structural aspect ratio, torsional to translational frequency ratio, stiffness eccentricity, soil earthiness and different types of seismic waves on the optimal eccentric positions of the VFDs are numerically evaluated. Through extensive numerical analysis and comparisons, the conclusions obtained herein will be much useful for the design of the VFDs for eccentric structures under earthquakes.