Optimal Design Of Structures With Magnetorheological Dampers

The structural vibration control using dampers can reduce the responses of the structures induced by ground motion effectively. The effectiveness depends on the capacity of the damper, the related control algorithm, the placement of the dampers in the structure and the load. Magnetorheological damper is a kind of intelligent actuator, which shows immense potential in the field of engineering structure. In this paper, Taking MR dampers as semi-active control device, the main contents of the thesis are summarized as follow:1. Studies on parameterized dynamic models of magnetorheological dampers are summarized in detail, the advantages and disadvantages of every model are analyzed. And the problem of how to design the control law making the dissipative ability of MR damper under fluctuating current be optimal is also discussed.2. Studies on control strategies of MR damper are summarized in detail, the advantages and disadvantages of every strategy are described.3. Taking velocity and interstory displacement responses as inputs, and treating controlled current as output, fuzzy control technique is adopted to MR dampers.4. A method based on improved genetic algorithm and equivalent quadratic performance index is presented to optimize the placements of the dampers, and an optimal design procedure of structures with MR dampers is proposed, too. At last, the method is approved to be simple and effective by an example.5. The coupled translational and torsional responses of a six story frame structure with bilateral eccentricities under the action of two-way horizontal seismic groundmotions are investigated.6. Participation matrix for the input control force is derivided in detail, and simulink analysis is done to the eccentric structure with MR dampers. The method based on improved genetic algorithm and equivalent quadratic performance index and the optimal design procedure are generalized to eccentric structures.