Comparative Study of Frames Using Viscoelastic and Viscous Dampers

Abstract

Identical mathematical expressions for viscoelastic and viscous damper-brace components are derived as the function of two fundamental nondimensional parameters. These two parameters are used to investigate the properties of viscoelastic (VE) and viscous (VS) systems by conducting parameter analysis. Usually both VS and VE damper-brace components provide added stiffness and damping to the whole system. The magnitude of the added stiffness and damping depends not only on the damper, but also on the interaction of the damper with other members of the frame. Under conditions of low frequency and stiff brace, the added stiffness provided by a VS damper-brace component is negligible. Based on harmonic theory, closed-form solutions for seismic response prediction are presented and are used to determine the optimal design. As an example, the seismic performance of a 10-story steel frame incorporated with VE and VS dampers is studied.