Damping Design of Multi-Vibration Modes For The Benchmark Problem of Wind-Excited Tall Building


Kazuto Seto,1 Fumio Doi2 and Yukito Matsumoto3

1Professor, Dept. of Mechanical Engineering, College of Science and Technology, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101, Japan
2Manager, Vibration Control Laboratory, 1-17-2 Fukuura, Kanazawa-ku, Yokohama, Japan
3Researcher, Vibration Control Laboratory

Keywords: Damping, Multi-vibration modes, Tall building, Dynamic Vibration Absorber


This paper proposes a method of damping design in tall building based on the vibration control technique in multi-degree-of-freedom system using dynamic vibration absorbers. Wind-exciting problem in tall buildings are caused mainly by lack of the internal damping in structures. Especially, as the tendency of constructing more reliable and lighter tower increases, it becomes insufficient to consider the first mode only, since the vibration of higher modes also raises problems for structure strength. For eliminating the problems, it is necessary to give the damping in multi-vibration modes to be required in structure externally. For the purpose, the vibration control method combined the modal analysis with the design method of the dynamic absorber is used. In order to show the effectiveness of the method, a 76-story 306 meters concrete office tower proposed in the benchmark problem is employed. It is demonstrated theoretically that a required damping has been obtained in the first fifth vibration modes of the structure using five dynamic absorbers.