The Wind Resistance Analysis Of Cable-stayed Space Truss Structure

Cable-stayed space truss is a kind of structure which consists of stayed cable, space truss and tower column. Compared with cable-stayed grid structure, it has less structural bars and nodes. In addition this structure is easy to hoist and build in a light and fine shape. Thus it is considered as a hybrid structural system, which will be popularized widely in future. Although many researchers studied about cable-stayed space truss structure, studies on the wind-induced response are seldom seen. As the main works in this paper, the following points will be discussed and analyzed based on the historical literatures.(1)Introduce the theoretical basis for nonlinear analysis of cable-stayed space truss structure system and explain the basic theory of calculation and analysis of cable-stayed space truss structure with finite element method.(2) Using finite element software "ANSYS" to do the modal analysis of cable-stayed space truss structure system after reasonable selection. The results show that cycle time of the first order of the cable-stayed space truss structure is 1.8s. Owing to this long cycle time and low vibration frequency, the structure is sensitive to wind load. Therefore it can be considered as a reasonable structure model for using the time-history analysis.(3)Summarize the basic theory of structural wind engineering and the artificial simulation method for fluctuating wind. Because wind vibration analysis is based on the simulation of fluctuating wind, in this paper according to WAWS method wind load is simulated by "MATLAB" software. In the simulation process H.A.Panofsky spectrum is utilized in the analysis of vertical wind spectrum, while about level wind spectrum Davenport spectrum is adopted as spectral density function. Then take the correlation of the wind field into consideration to obtain the cross spectral density function of any 2 nodes. As the conclusion from numerical results this program can simulate the fluctuating wind speed schedule quickly and effectively.(4) This thesis considers the wind-induced vibration condition under three working conditions of cable-stayed space truss structure. The three working conditions include single effect of vertical wind, single effect of horizontal wind and combined effect of vertical and horizontal wind. The results show that horizontal wind causes not only the vibration on the wind vibration direction, but also on the vertical direction. Through comparison and analysis, some conclusion is obtained to provide reference for similar projects.