OPTIMUM VISCOUS DAMPERS FOR STIFFNESS DESIGN OF SHEAR BUILDINGS

The problem in this paper is to find the optimum sets of story stiffne sses and of damping coefficients of the dampers of an elastic planar s hear building with viscous dampers (SBVD model) subject to constraints on maximum interstory drifts due to a set of spectrum-compatible eart hquake motions, on upper bounds for each damping coefficient of damper s, and on the sum of damping coefficients of dampers. Two basic charac teristics of an ordered set of optimum SBVD designs have been disclose d: (1) greater damping coefficients are distributed within the specifi ed upper bounds among the dampers placed on stories with greater inter story drifts; (2) the effect on stiffness reduction of the optimizatio n of the damping coefficients of dampers from an initial design of an SBVD model with uniform dampers is greater when non-uniform maximum in terstory drifts with larger differences between the minimum and maximu m values are specified. A design guideline for the effective configura tion of viscous dampers for stiffness design of an SBVD model is propo sed.