Vibration Research Of Stay-cable Under Non-gaussion Wind

Stay-cable vibration problem has always been a focus and difficult in the research,especially the spans of cable-stayed bridge now has more than a kilometre,such as sutong bridge with main span 1088 meters and cable length 577 meters,the influence of wind load on the vibration of cable is more and more important.The static parameter expressions such as the shape equation of stay-cable,the nonlinear equation of the beam-end tangent slope and so on,are derived according to the theory of catenary cable in this paper.In the process of calculating the stay-cable parameters,it is needed to assume the initial interval value of the beam-end cable tangent slope.However,in order to avoid the disadvantages of an arbitrary hypothetic interval,a graphic method is presented in this paper,which can draw the cable line and the tangent slope of the beam-end cable function diagram,from which the effective interval can be quickly obtained.Further,the beam-end tangent slope in the equation of the stay-cable shape is solved more accurately by utilizing the compiled program of the dichotomy algorithm.And,based on the solved beam-end tangent slope,the stay-cable parameters of cable-stayed bridge are calculated such as the cable length,the stay-cable slope of pylons-end tangent,beam-end and pylons-end cable tension.Finally,taking the Tongling Yangtze river highway bridge as an example,the effectiveness of the proposed algorithm is verified in this paper.The results show that it is more simple,intuitive and accurate to calculate the stay-cable parameters of cable-stayed bridge based on the combination the graphic method with the dichotomy.Considering of weight of cable and geometric nonlinear effects,cable movement differential equation was deduced in gaussian and non-gaussian wind load.Considering the first order modal of cable,the partial differential equations of cable was transformed into ordinary differential equations by using galerkin method.the gaussian wind load and non-gaussian wind load time history was simulated by using MATLAB.SIMULINK was used to analyze the cable movement differential equation of time history.Results show that the response of cable in gaussian wind load showed a non-gaussian characteristics,and the response of cable in non-gaussian wind load also showed a non-gaussian characteristics.the response of cable in gaussian wind load is more than the response of cable in non-gaussian wind load.The response of cable was positive and negative in gaussian wind load or in non-gaussian wind load,it makes cable reciprocating vibration to cause fatigue damage.The cable-deck coupling motion differential equations is developed and integral on [0,L] with the gaussian and non-gaussian wind load.The simulation model of cable and bridge deck motion equations is established and solved numerically with SIMULINK.finally,the displacement,velocity and acceleration response of cable is analyzed and compared in gaussian wind load and non-gaussian wind load.So is the desk.And the response of skewness and kurtosis value is statisticed.Results show that the most-positive displacement and most-negative displacement response of cable in non-gaussian wind load is more than in gaussian wind load.the most-positive displacement and most-negative displacement response of deck in non-gaussian wind load is almost equal in gaussian wind load and the amplitude is small.