Optimum viscous dampers for stiffness design of shear buildings

The problem in this paper is to find the optimum sets of story stiffnesses and of damping coefficients of the dampers of an elastic planar shear building with viscous dampers (SBVD model) subject to constraints on maximum interstory drifts due to a set of spectrum-compatible earthquake motions, on upper bounds for each damping coefficient of dampers, and on the sum of damping coefficients of dampers. Two basic characteristics of an ordered set of optimum SBVD designs have been disclosed: (1) greater damping coefficients are distributed within the specified upper bounds among the dampers placed on stories with greater interstory drifts; (2) the effect on stiffness reduction of the optimization of the damping coefficients of dampers from an initial design of an SBVD model with uniform dampers is greater when non-uniform maximum interstory drifts with larger differences between the minimum and maximum values are specified. A design guideline for the effective configuration of viscous dampers for stiffness design of an SBVD model is proposed.