SOME ISSUES ON WIND RESISTANT OPTIMIZATION DESIGN AND ON WIND-INDUCED VIBRATION CONTROL OF TALL BUILDINGS

Due to their long natural vibration periods and small damping, tall buildings are very sensitive to wind loading because of their high flexibility. Wind load is the main controlled load for the structural design of super tall buildings in coastal areas. Under the action of strong wind or typhoon, tall buildings must be designed to not only meet the safety requirements of design codes, but also to be economical and efficient. Therefore, it is of great practical significance to conduct some studies on wind resistant optimization design and on wind-induced vibration control of tall buildings. After a brief literature review on the wind resistant optimization design and on wind-induced vibration control of tall buildings, the wind resistant optimization design procedure of tall buildings is first proposed by considering the joint probability distribution of wind speed and direction, reliability analysis and performance based method. The minimum structural weight or cost are selected as design objective, the constraints for inter-storey and top drifts, wind-induced acceleration response at top floor are included, and the member size of structural elements are optimized in the optimization procedure. Meanwhile, another intelligent optimization algorithm such as the genetic algorithm is improved to increase its convergence speed and to obtain the most possible optimal solution, and the improved penalty function and hierarchical genetic algorithm are proposed in the genetic algorithm for the wind resistant optimization design. As for the structural topology optimization methods, the concept of hierarchical optimization is introduced in the variable density based topology optimization procedure, and the improved dynamic evolution rate is proposed to Bidirectional Evolutionary Structural Optimization (BESO) method for the topology optimization design of wind-resistant tall buildings. Then the effectiveness of the adopted wind resistant optimization algorithms are verified by several examples of wind resistant optimization design on practical tall buildings. In the aspect of wind-induced vibration control, a passive structural control system is proposed by combining the Friction Pendulum System and Tuned Mass Damper (FPS-TMD). The mechanical and dynamic characteristics of FPS-TMD system were studied, and the wind-induced vibration control theory of tall building with FPS-TMD system was also investigated. Taking the third-generation benchmark model for structural control study as an example, the wind-induced vibration control efficiency of such tall buildings with FPS-TMD system was first numerically evaluated under dynamic wind loading. Meanwhile the real-time hybrid test on the benchmark model was also conducted. The compared results from real-time hybrid tests with the numerical analysis method verify the wind-induced vibration control effectiveness of the proposed FPS-TMD structural control system.