The Experts below are selected from a list of 1848 Experts worldwide ranked by ideXlab platform
Jian Xin Liu - One of the best experts on this subject based on the ideXlab platform.
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Study of Aerodynamic Interference Effects on Staggered Double Thin-Walled Hollow Pier
Applied Mechanics and Materials, 2013Co-Authors: Jie Wang, Jian Xin LiuAbstract:In order to investigate the Aerodynamic Interference effects between parallel bridges, the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel continuous rigid frame bridges with high-pier and long-span were investigated in details by means of wind tunnel test. The tandem interval and side-by-side interval between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on Aerodynamic Interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 10 conditions. The research results have shown that the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The tandem interval and side-by-side interval between the two piers and wind direction angles are important factors affecting Interference effects. The drag coefficient, lateral force coefficient and torque coefficient are affected by these factors.
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Test Research on Aerodynamic Interference Effect on Aerostatic Coefficients of Main Beam in Parallel Bridge
Applied Mechanics and Materials, 2012Co-Authors: Jie Wang, Jian Xin LiuAbstract:Against the problem of the Aerodynamic Interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the Aerodynamic Interference effects on aerostatic coefficients of main beam in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test. The space between the two main beams and wind attack angles were changed during the wind tunnel test to study the effects on Aerodynamic Interferences of aerostatic coefficients of main beam. The test got aerostatic coefficients of 10 conditions. The research results have shown that the Aerodynamic Interference effects on aerostatic coefficients of main beam in parallel bridges can not be ignored. The Aerodynamic Interference effects on parallel bridge main beam is shown mainly as follows: The drag coefficient of main beam downstream dropped and the drag coefficient of main beam upstream changed but not change significantly. There are also the Aerodynamic Interference effects of lateral force coefficient and torque coefficient between the main beams upstream and downstream. The effects upstream are smaller and the effects downstream are larger.
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Experimental Study of Aerodynamic Interference Effects on Double Thin-Walled Hollow Pier in Tandem Arrangement
Advanced Materials Research, 2011Co-Authors: Jie Wang, Jin Yun Zhao, Jian Xin LiuAbstract:Against the problem of the Aerodynamic Interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test．The space between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on Aerodynamic Interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 8 conditions. The research results have shown that the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The Aerodynamic Interference effects on parallel bridge pier is shown mainly as follows: The tandem interval and wind direction angles are important factors affecting Interference effects. The drag coefficient of pier downstream dropped and the drag coefficient of pier upstream changed but Not change significantly. There are also the Aerodynamic Interference effects of lateral force coefficient and torque coefficient between the piers upstream and downstream. The effects upstream are smaller and the effects downstream are larger.
Jie Wang - One of the best experts on this subject based on the ideXlab platform.
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Study of Aerodynamic Interference Effects on Staggered Double Thin-Walled Hollow Pier
Applied Mechanics and Materials, 2013Co-Authors: Jie Wang, Jian Xin LiuAbstract:In order to investigate the Aerodynamic Interference effects between parallel bridges, the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel continuous rigid frame bridges with high-pier and long-span were investigated in details by means of wind tunnel test. The tandem interval and side-by-side interval between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on Aerodynamic Interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 10 conditions. The research results have shown that the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The tandem interval and side-by-side interval between the two piers and wind direction angles are important factors affecting Interference effects. The drag coefficient, lateral force coefficient and torque coefficient are affected by these factors.
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Test Research on Aerodynamic Interference Effect on Aerostatic Coefficients of Main Beam in Parallel Bridge
Applied Mechanics and Materials, 2012Co-Authors: Jie Wang, Jian Xin LiuAbstract:Against the problem of the Aerodynamic Interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the Aerodynamic Interference effects on aerostatic coefficients of main beam in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test. The space between the two main beams and wind attack angles were changed during the wind tunnel test to study the effects on Aerodynamic Interferences of aerostatic coefficients of main beam. The test got aerostatic coefficients of 10 conditions. The research results have shown that the Aerodynamic Interference effects on aerostatic coefficients of main beam in parallel bridges can not be ignored. The Aerodynamic Interference effects on parallel bridge main beam is shown mainly as follows: The drag coefficient of main beam downstream dropped and the drag coefficient of main beam upstream changed but not change significantly. There are also the Aerodynamic Interference effects of lateral force coefficient and torque coefficient between the main beams upstream and downstream. The effects upstream are smaller and the effects downstream are larger.
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Experimental Study of Aerodynamic Interference Effects on Double Thin-Walled Hollow Pier in Tandem Arrangement
Advanced Materials Research, 2011Co-Authors: Jie Wang, Jin Yun Zhao, Jian Xin LiuAbstract:Against the problem of the Aerodynamic Interference effects on aerostatic coefficients between parallel continuous rigid frame bridges with high-pier and long-span, the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in the parallel long-span continuous rigid frame bridges were investigated in details by means of wind tunnel test．The space between the two piers and wind direction angles were changed during the wind tunnel test to study the effects on Aerodynamic Interferences of aerostatic coefficients of twin piers. The test got aerostatic coefficients of 8 conditions. The research results have shown that the Aerodynamic Interference effects on aerostatic coefficients of double thin-walled hollow pier in parallel bridges can not be ignored. The Aerodynamic Interference effects on parallel bridge pier is shown mainly as follows: The tandem interval and wind direction angles are important factors affecting Interference effects. The drag coefficient of pier downstream dropped and the drag coefficient of pier upstream changed but Not change significantly. There are also the Aerodynamic Interference effects of lateral force coefficient and torque coefficient between the piers upstream and downstream. The effects upstream are smaller and the effects downstream are larger.
Zhengqing Chen - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation on Aerodynamic Interference of two kinds of suspension bridge hangers
Journal of Fluids and Structures, 2019Co-Authors: Yangchen Deng, Jun Huang, Zhengqing ChenAbstract:Abstract In order to study the Aerodynamic Interference between cables of suspension bridge hangers, two types of cable test models with smooth and rough surfaces, which respectively correspond to parallel wire strand (PWS) and wire rope (WR) hangers, were manufactured. The comparisons between the features of wake-induced vibration of the PWS and WR hangers were carefully investigated by means of wind tunnel tests. First, a series of force measurement tests for the two types of hangers were carried out to measure the mean Aerodynamic coefficients of the downstream cable within spatial region of 3 ≤ X ≤ 11 and -4 ≤ Y ≤ 4 with an interval of Δ X = Δ Y=0.25. The results of the force measurement tests show that obvious differences between the force coefficients of the downstream PWS and WR hangers are found. It seems that the variation amplitude of the force coefficient of the PWS hanger is significantly larger than that of the WR hanger. Moreover, the mean drag and lift coefficients of the downstream PWS hanger for U = 15 m∕s are obviously different from those for U = 10 m∕s , which indicates that the wake-induced vibration of the hanger might be strongly related to wind velocity (i.e., Reynolds Number). Second, a series of vibration measurement wind tunnel tests for the PWS and WR hangers were carried out to measure the responses of the downstream cables within the spatial region of 2.5 ≤ X ≤ 11 and 0 ≤ Y ≤ 4 with an interval of Δ X= Δ Y=0.25. The results show that obvious wake-induced vibrations are both observed for the PWS and WR hangers. However, it appears that the unstable region of the WR hanger is significantly less than that of the PWS hanger, which indicates that the WR cable seems to be more suitable than the PWS cable to be used as the hanger of suspension bridge. Parametric studies show that the wake-induced vibration of the PWS hanger is not divergent because the amplitude of the downstream cable stop increasing with the increase of the wind velocity, whereas the oscillation amplitude of the WR hanger keeps increasing with the increase of the wind velocity (up to 18 m/s in the wind tunnel). Moreover, it seems that the structural damping ratio have no significant influence on the critical wind velocity of the wake-induced vibration of the hanger of the suspension bridge.
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Experimental study of Aerodynamic Interference effects on aerostatic coefficients of twin deck bridges
Frontiers of Architecture and Civil Engineering in China, 2009Co-Authors: Zhiwen Liu, Zhengqing Chen, Gao Liu, Xinpeng ShaoAbstract:The Aerodynamic Interference effects on aerostatic coefficients of twin deck bridges with large span were investigated in detail by means of wind tunnel test. The distances between the twin decks and wind attack angles were changed during the wind tunnel test to study the effects on Aerodynamic Interferences of aerostatic coefficients of twin decks. The research results have shown that the drag coefficients of the leeward deck are much smaller than that of a single leeward deck. The drag coefficients of a windward deck decrease slightly compared with that of a single deck. The lift and torque coefficients of windward and leeward decks are also affected slightly by the Aerodynamic Interference of twin decks. And the Aerodynamic Interference effects on lift and torque coefficients of twin decks can be neglected.
Liu Zhi-wen - One of the best experts on this subject based on the ideXlab platform.
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STUDY OF Aerodynamic Interference EFFECTS ON Aerodynamic COEFFICIENTS OF TWIN-DECK BRIDGES
Engineering mechanics, 2008Co-Authors: Liu Zhi-wenAbstract:There exist Aerodynamic Interference effects between the windward deck and the leeward deck of twin-deck bridges under wind load.Aerodynamic Interference effects on Aerodynamic coefficients of a twin-deck bridge were investigated with a series of section-model wind tunnel tests using both force-measurement method and pressure-measurement method.The results show that the Aerodynamic Interference effects on drag coefficients of twin-deck bridges could not be neglected.Compared with single deck alone,the drag coefficients of leeward deck are much smaller and those of windward deck decrease slightly.The Aerodynamic Interference effects on the lift and torque coefficients of twin-deck bridge could be ignored.
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EXPERIMENT STUDY ON Aerodynamic Interference OF TANDEM CABLES BASED ON AEROELASTIC MODEL
Journal of Vibration and Shock, 2008Co-Authors: Liu Zhi-wenAbstract:The basic Aerodynamic Interference of tandem cables was investigated through a series of aeroelastic model wind tunnel tests. Cables with different spacing ratios, yaw angles, attack angles and natural frequencies were simulated and tested. It is found that the wake galloping, mainly in the form of out-plane vibration, occurs on the downstream cables on account of Interference engendered by upstream cables and on the upstream cables the same modal vibration appears however with smaller amplitude. The results also indicate that the critical wind velocity of wake galloping reduces with the decrease of spacing, and wake galloping mainly occurs at negative yaw angles and positive attack angles. Moreover, the critical velocity could be improved by raising natural frequency of the model. The wake galloping is a multiple-modes vibration and the mode participating levels vary regularly as wind velocity changes. The trajectory of wake galloping of the cable is an ellipse lying in first and third quadrants, and the main axes do not shift with the change of wind velocity. Finally, a numerical study using CFD method was applied to simulate flows around the tandem cables and to verify the rationality of the test results.
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Study of Aerodynamic Interference Effect on Main Girders of Twin-Deck Bridges
Bridge Construction, 2007Co-Authors: Liu Zhi-wenAbstract:The authors in this paper have made wind tunnel tests for segment models of two twin-deck bridges now being constructed in China and have conducted a study of the Aerodynamic Interference effect between the twin decks and the influences of the effect on the flutter stability,vortex-excited vibration and static Aerodynamic characteristics of the bridges.The differences of wind tunnel test results of the single deck and twin decks of the bridges reveal that the Aerodynamic mutual Interference that can not be negligible exists between the twin decks of the bridges and will possibly bring about adverse influence on the vibration of the bridges.
Zhu Ledong - One of the best experts on this subject based on the ideXlab platform.
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Aeroelastic and Aerodynamic Interference effects on a high-rise building
Journal of Fluids and Structures, 2017Co-Authors: Huang Dongmei, Zhu Ledong, Ding Quanshun, Zhu Xue, Chen WeiAbstract:Abstract The 492 m high Shanghai World Financial Centre is an interesting high-rise building in that the cross-section varies with the height. It is surrounded by a number of other buildings, including some of about half the height of it, a slightly lower nearby Jin Mao building, and a higher Shanghai Centre (not considered here). A series of wind tunnel tests for aeroelastic model vibration measurement and rigid model pressure measurement were carried out to investigate the aeroelasticity and Aerodynamic Interference effects on this building. The results show that, the densely clustered high-rise buildings (excluding the Jin Mao building) located upstream may cause the mean positive pressures of the lower obscured surface of the World Financial Centre to decrease, and the RMS pressures to increase or decrease for different configuration, which would exert some influences on the average and RMS responses. When buildings are located downstream, the wind-induced Aerodynamic Interference is negligible. When the Jin Mao building lies upstream, the mean positive pressures on the obscured surface of the World Financial Centre would decrease and even may become negative (the maximum absolute values may increase obviously), and the RMS pressures may also increase significantly, which cause the average displacement responses along-wind to reduce, the RMS horizontal displacement responses to increase, and the rotational displacement responses to increase for asymmetrical pressure. Moreover, it will weaken the energy and periodicity of vortex shedding of the World Financial Centre so as to reduce the possibility or amplitude of vortex resonance. More specifically, when the Jin Mao building lies downstream, the Interference effects of the wind loads and wind-induced vibration of rigid World Financial Centre are less obvious, however, when the aeroelasticity is considered at the same time, a significant vortex resonance arose in the direction along the first order modal of the World Financial Centre at a lower wind speed, for which the natural frequency is close to the vortex shedding frequency. The findings derived from the present study are believed to be useful to gain further insight into the aeroelasticity and Aerodynamic Interference effects of high-rise buildings.
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Aerodynamic Interference Effects on Flutter and Vortex-excited Resonance of Bridges with Twin-separate Parallel Box Decks
Journal of Tongji University, 2010Co-Authors: Zhu LedongAbstract:A case study was made of a preliminary design alterative for the broadening engineering of the existent single-tower cable-stayed bridge,Tanggu Haihe Bridge in Tianjin,with a main span of 310 m.The Aerodynamic Interference effects on flutter and vortex-excited resonance of cable-stayed bridges with twin-separate parallel box decks were investigated via a series of wind tunnel tests of spring-suspended sectional model.The results show that because of the Aerodynamic Interference between the two adjacent separate box decks,the flutter critical wind speeds of the twin-separate box deck bridge drops evidently and the turning point of the corresponding Aerodynamic derivative curve from descending to ascending is brought forward.Bridge flutter stability declines due to the Aerodynamic Interference of this type.Also,the maximal amplitudes of the vortex-excited resonance of the twin-separate box deck bridge in both the vertical and torsional directions increase due to the Aerodynamic Interference.Correspondingly,the lock-in zone of wind speed is widened,and the onset wind speed decreases.As a result,the Strouhal numbers increase slightly.It is also found that the Aerodynamic Interference effect between the two adjacent separate box decks is more significant on the flutter and vortex-excited resonance of the leeward deck than on those of the windward deck.Therefore,it is necessary to consider the Aerodynamic Interference effect when broadening an existent bridge into a twin-separate parallel deck bridge.