전단형 MR 감쇠기를 이용한 사장교 구조물의 진동제어 = Vibration Control of Cable-stayed Bridges Using Shear Type MR Damper

다국어 초록 (Multilingual Abstract)

The ultimate purpose of this research on the whole is to develop a vibration control method effectively applied for cable-stayed bridges which is structurally flexible, and to evaluate its effectiveness. As a primary step on the way to the ultimate goal, this paper describes our experiment on vibration control which was performed through the on-off control method of shear mode MR damper. The response values (displacement and acceleration) acquired from this experiment are contrasted with those of un-control method, and thus we evaluate the performance capacity of each different control method. For the experiment, we used a model bridge structure which was a reduced one of Seohae Grand Bridge one two hundredth in size, and also installed two shear mode MR dampers with electromagnetic yoke in the center of middle span. Also installing both displacement meters and accelerometers on each one fourth, two fourth, and three fourth position of the middle span, we estimated displacement and acceleration under each different control method. In order to measure the excitation of the structure, we use a shaker on the center of left span which would be able to perceive the El centro earthquake wave. The performance index we used were peak absolute displacement and peak absolute acceleration, by which the effect of controlling is evaluated. Finally, this paper concludes that the on-off control method using the MR damper turns out to be functionally superior to the un-control one, and thus the method is effective for the vibration control of cable-stayed bridges. It also proves that the results of the experiment performed in this research can be utilized as objective performance index in evaluating the effectiveness of the semi-active control which applies a variety of control algorithms.