In recent years many long-span bridges have been or are being constructed in the world, especially in China. Wind loads and responses are the key factors for their structural design. This paper introduces some importa...In recent years many long-span bridges have been or are being constructed in the world, especially in China. Wind loads and responses are the key factors for their structural design. This paper introduces some important achievements of wind-resistant studies of the author's research team on long-span bridges. First, new concepts and identification methods of aerodynamic derivatives and aerodynamic admittances were proposed. Then mechanical and aerodynamic control strategies and methods of wind-induced vibrations of long-span bridges were the great concerned problems, and valuable achievements were presented. Especially, great efforts which have been theoretically and experimentally made on rain-wind induced vibration of cables of cable-stayed bridges were described. Finally, some new progresses in computation wind engineering were introduced, and a new method for simulating an equilibrium boundary layer was put forward as well.展开更多
Based on the free vibration test method for extracting flutter derivatives,an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel.A separa...Based on the free vibration test method for extracting flutter derivatives,an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel.A separated twin-box girder section model was employed as the specimen.The flutter derivatives and critical flutter wind speed of this girder subject to both wind and rain(with various rainfall intensities,wind speeds and attack angles)were obtained,then the flutter stability of the bridge influenced by rainfall was analyzed.Experimental results showed that the flutter derivatives of this bridge depend on the angles of attack of wind flow in the wind and rain fields.Also,rainfall has great effect on three flutter derivatives(H2*,H4* and A4*)and has less effect on other three flutter derivatives(H1*,H3* and A3*).With the increasing rainfall density,the critical flutter velocity first increases and then decreases.Low density of rainfall has the effect of increasing mass,stiffness and damping on bridge decks,and higher density of rainfall has the effect of random inhomogeneous impact on bridge decks.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 59238161,59725818,50178049,50321803,and 50621062)
文摘In recent years many long-span bridges have been or are being constructed in the world, especially in China. Wind loads and responses are the key factors for their structural design. This paper introduces some important achievements of wind-resistant studies of the author's research team on long-span bridges. First, new concepts and identification methods of aerodynamic derivatives and aerodynamic admittances were proposed. Then mechanical and aerodynamic control strategies and methods of wind-induced vibrations of long-span bridges were the great concerned problems, and valuable achievements were presented. Especially, great efforts which have been theoretically and experimentally made on rain-wind induced vibration of cables of cable-stayed bridges were described. Finally, some new progresses in computation wind engineering were introduced, and a new method for simulating an equilibrium boundary layer was put forward as well.
基金supported by the Key Program of the Major Research Plan of the National Natural Science Foundation of China (Grant No.90815022)the National Natural Science Foundation of China (Grant No. 50908069)
文摘Based on the free vibration test method for extracting flutter derivatives,an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel.A separated twin-box girder section model was employed as the specimen.The flutter derivatives and critical flutter wind speed of this girder subject to both wind and rain(with various rainfall intensities,wind speeds and attack angles)were obtained,then the flutter stability of the bridge influenced by rainfall was analyzed.Experimental results showed that the flutter derivatives of this bridge depend on the angles of attack of wind flow in the wind and rain fields.Also,rainfall has great effect on three flutter derivatives(H2*,H4* and A4*)and has less effect on other three flutter derivatives(H1*,H3* and A3*).With the increasing rainfall density,the critical flutter velocity first increases and then decreases.Low density of rainfall has the effect of increasing mass,stiffness and damping on bridge decks,and higher density of rainfall has the effect of random inhomogeneous impact on bridge decks.
