Floor spectra of mixed base isolated structures

This work investigates the efficiency of mixed base isolation, combining passive isolation bearings with semi-active (SAC) devices, to reduce the floor spectral acceleration in the vicinity of the non-isolated modes’ frequencies. Both analytical and experimental studies have been carried out. Analytical results of the behaviour of a multiple degree of freedom base isolated structure demonstrate the efficacy of the method. Though the considered controller is based on a reduced order model with only two degrees of freedom (2 DOF) without spillover compensation, the results show that, for the type of structures studied here, spillover effects are not considerable. An experimental study of a 2 DOF model of a base isolated structure equipped with a semi-active magneto-rheological (MR) damper has been carried out. Due to limitations of the experimental set-up, it has not been possible to obtain direct experimental evidence of the efficacy of SAC control to improve floor spectra. Nevertheless, based on the good agreement between analytical and experimental results which validate the considered MR model and control algorithm, numerical analyses of more relevant configurations illustrated the benefit of the utilization of such devices.

[1]  L. Ljung,et al.  Control theory : multivariable and nonlinear methods , 2000 .

[2]  Ioannis Politopoulos,et al.  VULNERABILITY OF ELASTOMERIC BEARING ISOLATED BUILDINGS AND THEIR EQUIPMENT , 2005 .

[3]  E. D. Wolff,et al.  Experimental Study of Seismic Isolation Systems with Emphasis on Secondary System Response and Verification of Accuracy of Dynamic Response History Analysis Methods , 2004 .

[4]  James M. Kelly,et al.  Active Control and Seismic Isolation , 1991 .

[5]  T. T. Soong,et al.  Base isolated structures with active control , 1987 .

[6]  N. Wongprasert,et al.  Experimental Evaluation of Adaptive Elastomeric Base-Isolated Structures Using Variable-Orifice Fluid Dampers , 2005 .

[7]  Ioannis Politopoulos,et al.  A review of adverse effects of damping in seismic isolation , 2008 .

[8]  Nicos Makris,et al.  RIGIDITY–PLASTICITY–VISCOSITY: CAN ELECTRORHEOLOGICAL DAMPERS PROTECT BASE‐ISOLATED STRUCTURES FROM NEAR‐SOURCE GROUND MOTIONS? , 1997 .

[9]  Billie F. Spencer,et al.  Semiactive control strategy for a phase II smart base isolated benchmark building , 2008 .

[10]  James M. Kelly,et al.  Seismic response of the superstructure and attached equipment in a base‐isolated building , 1989 .

[11]  André Preumont,et al.  Vibration Control of Active Structures: An Introduction , 2018 .

[12]  James M. Kelly,et al.  Hybrid isolation systems for equipment protection , 1993 .

[13]  Jeong-Hoi Koo,et al.  A comprehensive analysis of the response time of MR dampers , 2006 .

[14]  Dimitrios Konstantinidis,et al.  The Influence of Isolator Hysteresis on Equipment Performance in Seismic Isolated Buildings , 2010 .

[15]  José Rodellar,et al.  Predictive control of base‐isolated structures , 1992 .

[16]  Sriram Narasimhan,et al.  Control of smart base isolated buildings with new semiactive devices and novel H2/LQG, H-infinity and time-frequency controllers , 2005 .

[17]  Andrew S. Whittaker,et al.  Seismic performance assessment of base‐isolated safety‐related nuclear structures , 2010 .

[18]  James M. Kelly,et al.  The role of damping in seismic isolation , 1999 .

[19]  Stefan Hurlebaus,et al.  Fuzzy control of piezoelectric friction dampers for seismic protection of smart base isolated buildings , 2010 .

[20]  Horia Alejandro Barbat Barbat,et al.  Parameter identification of large-scale magnetorheological dampers in a benchmark building platform , 2009, 2009 European Control Conference (ECC).

[21]  Kazuto Seto,et al.  Active Control of Structures , 2008 .

[22]  John P. Wolf,et al.  Response of a nuclear power plant on aseismic bearings to horizontally propagating waves , 1983 .

[23]  Andrew S. Whittaker,et al.  Seismic demands on secondary systems in base‐isolated nuclear power plants , 2007 .

[24]  Seung-Ik Lee,et al.  A hysteresis model for the field-dependent damping force of a magnetorheological damper , 2001 .

[25]  JONATHAN HANCOCK,et al.  AN IMPROVED METHOD OF MATCHING RESPONSE SPECTRA OF RECORDED EARTHQUAKE GROUND MOTION USING WAVELETS , 2006 .

[26]  James M. Kelly,et al.  Seismic response of heavily damped base isolation systems , 1993 .

[27]  James M. Kelly,et al.  Non‐classical damping in dynamic analysis of base‐isolated structures with internal equipment , 1988 .

[28]  J. P. Wolf,et al.  Effects of horizontally propagating waves on the response of structures with a soft first storey , 1981 .

[29]  William T. Holmes,et al.  The 1997 NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures , 2000 .

[30]  Henri P. Gavin,et al.  FAULT TOLERANCE OF SEMIACTIVE SEISMIC ISOLATION , 2003 .

[31]  James M. Kelly,et al.  Seismic response of light internal equipment in base‐isolated structures , 1985 .

[32]  Ioannis Politopoulos.  Response of seismically isolated structures to rocking-type excitations , 2009 .

[33]  Satish Nagarajaiah,et al.  Control of structures with friction controllable sliding isolation bearings , 1993 .

[34]  Henri P. Gavin,et al.  A parametric study of linear and non-linear passively damped seismic isolation systems for buildings , 2004 .

[35]  Satish Nagarajaiah,et al.  Seismic control of smart base isolated buildings with new semiactive variable damper , 2007 .

[36]  Satish Nagarajaiah,et al.  Semi‐active control of sliding isolated bridges using MR dampers: an experimental and numerical study , 2005 .

[37]  Francesc Pozo,et al.  A velocity-based seismic control for base-isolated building structures , 2009, 2009 American Control Conference.

[38]  Michael C. Constantinou,et al.  Seismic testing of a building structure with a semi-active fluid damper control system , 1997 .

[39]  Shirley J. Dyke,et al.  An experimental study of MR dampers for seismic protection , 1998 .

[40]  James M. Kelly,et al.  Robust control of base-isolated structures under earthquake excitation , 1987 .

[41]  J. Juang.  Applied system identification , 1994 .

[42]  Zexiang Li,et al.  Control of seismic-excited buildings using active variable stiffness systems , 1996 .

[43]  Jonathan W. Bender,et al.  Properties and Applications of Commercial Magnetorheological Fluids , 1998, Smart Structures.

[44]  Tatjana Isaković,et al.  Floor response spectra in isolated structures subjected to earthquakes weaker than the design earthquake—Part I: Isolation with high-damping rubber bearings , 2011 .

[45]  Hamid Reza Karimi,et al.  Semiactive control of a base isolated building using magnetorheological dampers , 2009, Int. J. Model. Identif. Control..