Comparison of distribution methods for viscous damping coefficients to buildings

A simple and convenient method often adopted by practising engineers designing supplemental viscous dampers to a building is to calculate damping coefficients of viscous dampers corresponding to a desired added damping ratio. To facilitate the design, various methods for distributing damping coefficients along the height of the building are compared in the study. In the article, two non-repetitive distribution methods are proposed and compared with some often adopted methods and a repetitive simplified sequential search algorithm. Numerical studies of three planar frames in which two are vertically irregular have indicated that all distribution methods may result in similar seismic responses if added damping ratio are the same. Nevertheless, compromising among a few design factors such as the total added damping coefficient, maximum damper force at one storey, total added damper force, control of storey drift and total computational efforts, one of the two proposed methods distributing the damping coefficient only to 'efficient storeys' may provide one of the better choices for the practical design of viscous dampers.