Wind-induced Vibration Analysis On Fluid-structure Interaction For Cable Structures

Cable structures are widely used in constructions including cable suspended roof, curtain wall, transmission tower-line system, bridge and guyed mast. Wind effects become one of the dominating factors that must be considered due to the low weight and bending stiffness for structures. Since damage and failure of cable occur often in wind, wind-induced vibration of cable structures is paid more and more attention by both engineers and researchers. Wind load applied on cable structures is random and space-correlated, and cable itself has complicated mechanical properties. Wind induced response of cable structures is the research focus in wind engineering field, and the research on mechanism is still need to be promoted. At present some researchers already start studying cable's vibration on fluid-structure interaction(FSI) effect, but section model or two-dimensional approximate model is usually adopt in the study of cable's FSI effect by wind tunnel tests or numerical simulation, which has low calculation accuracy..Three-dimensional model of long cable structures is used in this paper for FSI multi parameter analysis. In this paper the author focuses on the following aspects: analysis methods of FSI, wind field simulation, vibration mechanism of cable structures and dynamic response of wind-induced vibration. Firstly, the research on wind engineering of cable structures is reviewed, the existing major questions are presented, and the future research work and target is discussed.Secondly, the basic theory of structural wind engineering are introduced, analysis methods of cable's vibration are investigated, different types of cable's wind-induced vibration and their mechanisms are analyzed.Thirdly, techniques of wind tunnel tests and numerical simulation of wind speed time series are studied. Wind pressure coefficient of a closed-end double slope roof and an arched roof are calculated by computational fluid dynamics numerical simulation technique, compared with national load code. Forthly, basic principles of computational fluid dynamics(CFD) and computational structure dynamics(CSD) are described; coupling mechanism and research progress of FSI are discussed; calculation scheme and basic principle of FSI under ANSYS-CFX environment are introduced.Then, long cable's dynamic response on FSI effect in steady wind field are calculated and analyzed under multi-parameter condition and some useful conclusions are obtained, compared with results on rigid models. Single steel cable with circular section and D shape section are simulated first, then several models with different parameters,such as inclined angle, yaw angle, wind velocity and prestress level of cable. K and omega turbulent model and laminar model are used to simulate fluid flow seperately. Then two series connected cables and parallel connected cables are simulated. Time history curves of displacement, pressure, stress and some wind-induced vibration rules are obtained.Finally, based on the research work in this dessertation, some useful conclusions are drawn and some problem to be furtherly considered are indicated.