Viscous Dampers: Testing, Modeling and Application in Vibration and Seismic Isolation

Keywords: Secondary Systems, Viscous Dampers, Seismic Isolation, Vibration Isolation, Passive Protective Systems, Piping Systems, Industrial Equipment, Viscodampers, Teflon Disc Bearings, and Steel Springs.

Abstract: A fractional derivative Maxwell model is proposed for viscous dampers which are used for vibration isolation of piping systems, forging hammers and other industrial equipment, as well as for vibration and seismic isolation of building structures. The development and calibration of the model is based on experimentally observed dynamic characteristics. The proposed model is validated by dynamic testing and very good agreement between predicted and experimental results is obtained. Some analytical results for a single-degree-of-freedom viscodamper system are presented. These results are useful to the design of vibration isolation systems. An equivalent viscous oscillator is defined whose response is essentially the same as that of the viscodamper isolator. The model is employed in the analysis of a base-isolated model structure which has been tested on a shake table.