Design of supplemental viscous dampers in inelastic SDOF system based on improved capacity spectrum method

A simplified yet effective design procedure for viscous dampers was presented based on<br />improved capacity spectrum method in the context of performance-based seismic design. The amount of<br />added viscous damping required to meet a given performance objective was evaluated from the difference<br />between the total demand for effective damping and inherent damping plus equivalent damping resulting<br />from hysteretic deformation of system. Application of the method is illustrated by means of two<br />examples, using Chinese design response spectrum and mean response spectrum. Nonlinear dynamic<br />analysis results indicate that the maximum displacements of structures installed with supplemental<br />dampers designed in accordance with the proposed method agree well with the given target displacements.<br />The advantage of the presented procedure over the conventional iterative design method is also<br />highlighted.