Analytical Model of Viscoelastic Fluid Dampers

Abstract

An analytical approximate constitutive relation is derived for a form of fluid damper, which exhibits viscoelastic behavior. The damper is used for vibration isolation of piping systems and industrial equipment, as well as for vibration and seismic isolation of building structures. The damper consists of an open pot, filled with highly viscous fluid, and a piston that moves within the fluid. The analytical solution relates the damping constant of the unit at vanishingly small frequencies with the material constants of the fluid used in the damper and the geometric characteristics of the damper. With the determination of the damping constant, a macroscopic model may be constructed that describes the damper behavior over a large frequency range. The other parameters of the macroscopic model are identical to those in the corresponding constitutive relation of the damper fluid. The results of the analytical solution are in very good agreement with experimental data and with numerical solutions based on boundary‐element analysis.