The Analysis On Fluid-Structure Coupled Vibration Of Stay Cable Based On Overset Mesh Method

Using the CFD software FLUENT and the nested grid method,the vortex-induced vibration response of the optical circular cable under different reduced wind speeds is analyzed,and the fluid-structure interaction numerical study of the crescent-shaped ice-coated cable under different wind speeds.The main research contents are as follows:(1)The types and research status of wind-induced vibration of stay cables are introduced in detail,and the control equations and solution methods used in the fluid-structure interaction of stay cables are introduced in detail.Using the nested grid method,using the secondary development interface provided by the software,embedded the self-edited Newmark-β method program to solve the vibration equation,obtain the dynamic response of the cylinder,and analyze the vortex-induced vibration of the low mass ratio cylinder with elastic support,Verified the reliability of the numerical method.(2)Analyze the vortex-induced vibration response of the cable at different reduced wind speeds,focusing on the aerodynamic force,vibration frequency,vibration displacement,and trajectory of the optical circular cable at different reduced wind speeds.The vortex-induced vibration analysis of the cable shows that when the reduced wind speed Ur≤4.64,the cross-wind displacement of the cable presents a significant "beat" feature.After the FFT transformation of the cross-wind vibration displacement,it is found that the frequency spectrum shows two The more obvious peaks are the two main vibration frequencies of the cable vortex-induced vibration;when the reduced wind speed Ur>4.857,the cable cross-wind direction displacement spectrogram shows an obvious single peak characteristic.The trajectory of the vortex-induced vibration of the cable is analyzed in detail.The cable is of high quality than the vortex-induced vibration,and its trajectory is more abundant.Only in the range where the vortex-induced vibration occurs,the cable is roughly "8".Movement track.(3)The mass ratio will have a certain impact on the vortex-induced vibration of the cable,which is an important factor affecting the vortex-induced vibration.Through the analysis of the low mass ratio vortex-induced vibration,it can be concluded that the smaller the mass ratio,the larger the locking interval,and the larger the amplitude of the cable.The center of mass motion trajectory of the cable shows a relatively regular "8"-shaped movement.(4)Analyze the fluid-solid interaction problem of the crescent-shaped ice-coated cable.And analyze in detail the effect of ice coating on the fluid-solid interaction vibration of the cable;analyze the fluid-solid interaction problem of the ice-coated cable with elastic support under different initial angles of attack,It can be concluded that the ice-coated cable has a certain inhibitory effect on the vortex-induced vibration at a small wind attack angle(0°~30° wind attack angle);and when the wind attack angle increases to 40° When the time,the vortex-induced vibration interval of the ice-coated cable increases and the amplitude increases to a certain extent;when the wind attack angle increases to 90°,the vortex-induced vibration interval of the cable is the same as the optical circle cable,but the amplitude It has improved significantly.(5)Research the aerodynamic response characteristics of the ice-coated cable under high wind speed at the full angle of attack,and further study the gallop of the ice-coated cable under high wind speed.When the initial wind attack angle is 30°,the galloping numerical simulation of ice-coated cables with different damping ratios is carried out.When the damping ratio is low,the wind speed at which the ice-coated cable gallops is lower;with the increasing damping ratio,the wind speed at which the ice-coated cable gallops increases accordingly.