Seismic response of dynamically similar adjacent structures connected with viscous dampers

Abstract

Structural control by implementing energy dissipation devices or control systems into structures is more effective in reducing excessive structural vibrations because of natural disturbances. This article describes the application of viscous damper for response control of seismically excited dynamically similar adjacent coupled structures. The investigation is carried out to study the structural responses of two dynamically similar structures connected with viscous dampers subjected to four different types of earthquake ground motions. A formulation of the equations of motion for the two adjacent multi-degrees-of-freedom (MDOF) structures connected with viscous dampers is presented. The numerical study is carried out in two parts, namely (a) two adjacent MDOF structures connected with viscous dampers having same damper damping coefficient and (b) two adjacent MDOF structures connected with viscous dampers having different damper damping coefficients. The damper effectiveness is investigated in terms of the reduction of structural responses (namely, displacement, accelerations and base shear force) of the connected adjacent structures. A parametric study is also conducted to investigate the optimum damper damping coefficient of the dampers. Results show that using viscous dampers to connect the adjacent dynamically similar structures can effectively reduce earthquake-induced responses of either structure by selecting appropriate damping coefficient of dampers. Further, lesser damper at appropriate locations can significantly reduce the earthquake response of the coupled system. The reduction in responses when two MDOF structures connected with 50% of the total dampers at appropriate locations is almost as much as when they are connected at all floors, thereby the cost of the dampers can be minimised. © 2010 The Institution of Engineers, Singapore.