Study On Hybrid Control With Base Isolation And Three-Dimension Isolated System

In this dissertation, on the base of the state-of-art review in the field ofstructural vibration control at home and abroad, how to improve the controlefficiency of base-isolation system was studied. In order to more diminish thehorizontal seismic reaction of base isolation building, especially high-risebase-isolated building, hybrid control systems, the upper structure (above baseisolated layer) attached semi-active variable stiffness/damping control device(BI&AVSD), passive variable stiffness device (BI&PVS) or passive variabledamping device (BI&PVD), are put forward. Then, the shaking table testing andnumerical simulation about these hybrid control systems were carried through;inaddition, the control efficiency about Fuzzy control was discussed. With a view tothe limitation that the preset base isolation system can not decrease the verticalseismic reaction, a new type complex three-dimension isolated device wasdeveloped, and the earthquake simulation shaking table testing and numericalsimulation of the base isolation system using this new device were finished. Themain achievements and contents including:1. The testing and numerical simulation analyses of simple hybrid controlsystem indicate: when AVSD in BI&AVSD employs sign control law, the variablestiffness mechanism play the leading effects. Comparing with only base isolationsystem (BI), BI&AVSD can diminish distinctly the drift of upper structure, butcan not control effectively the acceleration of the isolated layer and upperstructure. The pulse resulted from the on-off of semi-active control device maymagnify the acceleration reaction. Comparing with BI, BI&PVD can more diminish acceleration reactions, butcan not improve the control efficiency of drift reactions. The control effect ondrift in BI&PVS is close to that in BI&AVSD, and the control effect onacceleration in BI&PVS is not perfect too.According as the design requirement of base isolation system, the differenthybrid control mode (BI&AVSD, BI&PVS or BI&PVD) can be selectedconcretely. The semi-active hybrid control system (BI&AVSD) has on-lineadjusted ability, and can adapt to the random characteristic of earthquake wave;the passive hybrid control system (BI&PVS or BI&PVD) has advantage ofsimple device.2. Through numerical simulation, the different control effect related to thevariable attached stiffness and damping was studied. To add properly attachedstiffness can increase control effect on drift of upper structure in BI&AVSD andBI&PVS;to add properly attached damping can improve the control effect ofBI&PVD, and to add attached damping may decrease the acceleration pulse fromsemi-active control device's on-off switch in BI&AVSD.3. Apply Fuzzy control theory into the semi-active hybrid control system(BI&AVSD), then Fuzzy Control Based Mode Identification (MF) was putforward. The numerical simulation indicate: control effect using this fuzzycontrol strategy is a little better than that using sign control law, BI&AVSD orAVSD using this fuzzy control strategy, attached relative small stiffness anddamping can achieve the same control effect as that using sign control law;moreover, fuzzy control can reduce the pulse effect from on-off switch, thendiminish the acceleration reaction.4. The numerical simulation study on high-rise hybrid isolation controlsystem was performed, thereinto adopt the main vibration mode control law. Thenumerical simulation analyses indicate: comparing with BI, BI&AVSD cancontrol effectively the drift of upper structure and reduce the acceleration reactionof most storey, at the same time only impact slightly the isolated layer's reaction;comparing with BI&AVSD, BI&PVS can control effectively the drift of someunderpart storey, but can not control effectively the acceleration reaction;BI&PVD can cut down largely the acceleration of isolated layer and upperstructure, and can control effectively the drift of upper structure. To adopt hybridcontrol mode and select rationally the control parameter (attached stiffness anddamping) can improve the anti-seismic performance of high-rise isolatedbuildings.5. Develop a kind of vertical semi-active isolated device with disk spring.Combining vertical semi-active isolated device with horizontal isolated bearingcan realize three-dimension isolation, and put forward a semi-active controlstrategy suited to vertical semi-active isolated control. The control efficiency ofthree-dimension isolation system was validated through the shaking table testsand numerical simulation, this research help to reform the isolation technique inhigh intensity zone.