Maxwell Model of Fluid Viscous Dampers in Elastic and Inelastic SDOF Systems

A computer algorithm is developed for the numerical simulation of fluid viscous dampers (FVDs), represented by a Maxwell model in elastic and inelastic SDOF systems for nonlinear dynamic analyses under near-field (NF) and far-field (FF) earthquake motions. Maxwell model incorporates the frequency dependence of the damping and stiffness coefficients observed in the fluid orifice of FVDs, which is characterized by three basic parameters (supplemental damping ratio \({\xi }_{add}\) , velocity power \(\alpha \) , and axial stiffness \({k}_{s}\) ). The computational efficiency of the algorithm is verified against experimental example in previous research. This study shows the effect of NF and FF on energy dissipated by FVD ( \({E}_{d2}\) ) with varying system ductility level µ, \({\xi }_{add}\) and \(\alpha \) . The selection procedure of axial stiffness ( \({k}_{s}\) ), based on energy-dissipated spectra, is proposed in this study to obtain the optimal values of \({k}_{s}\) in extensive response history analyses of SDOF systems. It is found that the \({k}_{s}\) size of FVD is more significant to structural properties (natural vibration period \({T}_{n}\) , and µ), and FVD characteristics ( \({\xi }_{add}\) and \(\alpha \) ).