Parametric study and prediction models of the seismic response of single-degree-of-freedom structural systems equipped with Maxwell material fluid viscous dampers

Abstract

The addition of supplemental damping through fluid viscous dampers has been widely implemented as a seismic protection system for diverse typologies of structures. Typically, fluid viscous dampers are modelled using a Maxwell material model, which accounts for the stiffness of the damper device and its support assembly. However, the influence of the different parameters involved in the design of Maxwell fluid viscous dampers on the dynamic response of damped systems subjected to transient loads has not been studied thoroughly, especially regarding the acceleration response of dynamic systems. This paper discusses the results of a parametric study of the influence of several damper's design parameters, such as the velocity exponent, the supplemental damping level, the seismic intensity, and the Maxwell material stiffness, and the interaction among them, on the seismic response of viscously damped single-degree-of-freedom structural systems. Non-linear time history analyses were carried out using the FEMA P-695 far-field ground motion set scaled to four increasing intensities. The seismic response was measured in terms of peak relative displacements, peak relative velocities, peak damper forces, peak floor absolute accelerations, and peak floor absolute acceleration response spectra. Based on the obtained seismic responses, several prediction models were proposed using Gaussian Process Regression to provide an insight into the influence of the different design parameters of fluid viscous dampers on the seismic response of viscously damped single-degree-of-freedom structural systems. The results show that the different parameters involved in the design of Maxwell fluid viscous dampers significantly influence the efficiency of damper devices and the seismic response of the single-degree-of-freedom structural systems, especially in terms of acceleration response. For particular combinations of the damper's design parameters, significantly higher floor spectral accelerations can be observed in some period ranges compared to those of control systems without dampers. Additionally, the floor absolute acceleration response spectra exhibit a stiffening effect caused by the implementation of fluid viscous dampers, shifting peak floor spectral accelerations to shorter periods. The magnitude of the stiffening effect is proved to be correlated to the Maxwell material stiffness value.