Analysis Of Wind-rain-induced Vibration Characteristics Of Continuous Elastic Cable

As the main force member of the cable-stayed bridge,the cable vibration is easy to occur under various factors because of its lightweight,large flexibility and low damping,among which the wind-rain-induced vibration of cable is a kind of large,low-frequency vibration.It is harmful to the safe operation of cable-stayed bridge.Scholars at home and abroad have made extensive research on the wind-rain-induced vibration of cables,but there are still many deficiencies in existing theories.Based on the existing theoretical models,a more reasonable theoretical model of the wind-rain-induced-vibration of the cable is established in this paper,and the vibration characteristics of the wind-rain-induced vibration of the cable is analyzed.Using the existing theoretical model of wind-rain-induced vibration of cable based on catenary static model considering only in-plane vibration,the nonlinear analysis of the wind-rain-induced vibration of cable is carried out.The chaotic motion of cable and rivulet and the effect of damping ratio on the amplitude and chaotic motion of cable are studied.The results show that the wind-rain-induced vibration of cable is a typical nonlinear vibration,and increasing to a certain damping ratio can suppress the vibration of cable.And the damping ratio has a great influence on the nonlinear vibration of the cable,and the influence of wind speed on the wind-rain-induced vibration of the cable is analyzed in combination with the theoretical model of the wind-rain-induced vibration of the segmental cable.The effects of wind speed,? value and phase difference on the wind-rain-wind induced of cable are studied.The results show that the variation of wind speed will affect ? value,and then affect the amplitude of cable.A theoretical model based on catenary static type considering the internal and external free vibration of the cable plane is established.By calculating the natural frequencies of each order of the cable,the in-plane and out-of-plane free vibration of the cable be compared.The influence of cable parameters and different line types on the natural vibration frequency is analyzed.The results show that the influence coefficient of sag obtained by the two kinds of lines is the same as the variation of cable length,line mass and tension.The trend of variation with cable inclination is opposite.By considering the existence of Coulomb damping force and viscous linear damping force between the rivulet and the cable surface,a theoretical model of wind-rain-induced vibration of rivulet continuous elastic cables with in-plane and out-of-plane vibration is established based on the catenary static model represented by various modes of cable.Thecharacteristics of cable vibration and the axial distribution of rivulet along cable are analyzed.The difference of wind-rain-induced vibration between different cables is compared.The effects of catenary static type and parabolic static type on the wind-rain-induced vibration of cable are studied.The vibration characteristics of the cable induced by wind and rain are obtained by using the catenary model,and the vibration characteristics obtained by using the parabola are obtained at the cable amplitude and the parametric mode.The axial distribution of rivulet and ? value along the cable axis,the phase difference between the cable and the rivulet is quite different.Under some wind speed,the parametric mode will change and the actual vibration form will be different.Through the above research,this paper verified the rationality of using catenary static,analyzes the characteristics of wind-rain-induced vibration of cable,for the further study the excitation mechanism of wind-rain-induced vibration of cable provides a good reference.