Optimal Use of Viscoelastic Dampers in Building Frames for Seismic Force

Control of the seismic response of multistory building frames using optimally placed viscoelastic dampers (VEDs) is investigated. Responses are obtained in frequency domain using spectral analysis for narrow and broad band stationary random ground motions. Optimal locations of passive VEDs are found with the help of a controllability index, which is obtained with the help of the root-mean-square value of the interstory drift. To highlight the effect of modeling and optimal location of VEDs on the response reduction, three different mathematical models of the VEDs and three alternative schemes of placement of VEDs are considered. The response of the 20-story shear-frame model is controlled by the proposed strategy. It is shown that the scheme of the optimal placement of VEDs provides more reduction in response compared with other schemes of placement of VEDs considered in the study. Furthermore, the optimal placement of dampers is sensitive to the nature of excitation force, total quantity of viscoelastic material used, and the modeling of VEDs.