The Research On Wind-induced Vibration Control Of A New Damped Outrigger System

With the increase of building height, the stiffness and damping of structure is declining, generating obvious seismic response and wind-induced vibration. The traditional structure design resists seismic load or wind load by increasing lateral stiffness of the structure such as setting outriggerr But it can easily generate weakness story due to the mutation of structural stiffness and internal forces. Therefore, auxiliary control device become popular in the vibration control of high-rise building. As a new energy dissipation system, the damped outrigger system separates the outrigger and perimeter columns and inserts viscous dampers across this structural discontinuity to make full use of the relative big displacement of these two components. Based on previous studies, a new simplified model for damped outrigger system is put forward, then its control effect under external wind loads is studied under both concepts of control device and strengthened story, and a practical method of optimal damper placement is given at last. Following is the main content of this paper:Firstly, considered the restraint of frame on core tube, the core tube is simplified as a Timoshenko beam with one end fixed and dynamic model of the energy dissipation system is established. The main characteristics of the new control system are initially obtained through model parameters analysis, then the control effect of a high-rise building with a damped outrigger system under external wind loads are verified through numerical simulation. The numerical result turns out that the damped outrigger system has a significant effect on structural wind-induced vibration control.Secondly, compare the control effect of damped outrigger under external wind loads with the effect of strengthened story, and some meaningful conclusions can be achieved. Based on the characteristics of the two wind-induced vibration control systems and the theory of strengthened story, wind-resistant structure with multiple strengthened stories and damped outrigger systems is presented. The numerical analysis indicates that structure with multiple strengthened stories and damped outrigger systems behaves very well if the whole rigidity of the structure is not enough.Finally, based on the theory of structural topology optimization and the characteristics of damped outrigger system, a practical method of position optimization of structure with multiple strengthened stories and damped outrigger systems is put forward. Numerical example shows that, compared with the optimal solution of successive approximation, the method proposed in this chapter produces control effect almost as good as the optimal solution except for simple and practical.