| The dissertation was finished under the financial support of the National Natural Science Foundation of China under NNSF-50038010 and The Hong Kong Polytechnic University through its Area of Strategic Development Programme in Structural Control under 1.31.37.A204 and Intelligent Building under 1.31.37.A234.Accoring to the whipping effect of the seismic responses of the tall building with a podium structure, the dissertation begins to research the semi-active control of seismic responses of tall building with podium structure using MR dampers based on the theory proposed by Qu W.L. and Xu Y.L. (2001), whose title is "semi-avtive control of seismic responses of tall buildings with podium structure using ER/MR damper. Analysis in theory, numerical simulation and experimental investigation on seismic simulator are employed to carry out the research. The logic control algorithm based on PanBoolean algebra was first introduced into structural control field. The semi-active logic control algorithm was proposed, which includes six kinds of semi-active logic control method. They are the semi-active logic control method A, B and C for single MR damper, the semi-active logic control method D, E and F for multiple MR dampers.A series of numerial simulation and experimental investigations on the seismic responses of the tall building with a podium structure using single damper /multiple MR dampers were first carried out on the seismic simulator in The Hong Kong Polytechnic University on 2002-2003. The tall building with podium structure model were designed and constructed. The dynamic characteristics of structure were calculated and tested. The simulation system was developed with which the seismic responses of the tall building with podium structure using MR single damper/multiple MR dampers were simulated. The experimental system on seismic simulator was set up and whose control roftware were developed. Analyzing Automatically data method was advanced and its roftware was designed. The methodology of the collecting responses of structure was obtained was proposed. In case of the control system with multiple MR dampers, the paper discusses the selection of observation point, and the general rules of sensors placement as to solve the problem in practical experiment.The experimental results on seismic simulator verify that the MR damper in the passive off mode provided the information on the minimum effectiveness of the damper if the external power was cut off, in which the seismic responsesof the tall building and podiun structure were reduced. When the MR damper worked in the six kinds of semi-active logic control methods, the seismic responses of the two building were further reduced compared with those when the MR damper worked in the passive off mode. The effectiveness and efficiency of the multiple MR dampers were higher than those of the single MR damper. The major advantages of the proposed semi-active multilevel logic control algorithms include the quick and simple control decision without requiring the accurate mathematical models for the control system and the MR damper, the full utilization of the nonlinear features of the MR damper, and the high reliability and robustness. The performance and effectiveness of the semi-active logic control algorithm could only depend on the control algorithm itself without structural system model and is not affected by external disturbance, in which the analysis is simplified and the control performance is enhanced. The semi-active logic control algorithm has the high adaptability for different kinds of ground excitations. The effectiveness and efficiency of the proposed semi-active logic control algorithm was higher than those of the clipped-optimal algorithm, which is one of the most popular control algorithms used at present for MR dampers. Moreover, it more adaptive to change in ground excitation. Hence, the semi-active logic control algorithm is a kind of new structural intelligent semi-active control algorithm in practical engineering.
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