Rods Of Circular Cross Section Vortex Induced Vibration Suppression Structure

The quayside container crane is the main equipment of loading and unloading of port, and its position and function are given more and more attention. Being the main technology element of port, it's the symbol of production capability. The more and more large-scale quayside container cranes are designed and manufactured. Their sizes become larger than ever. The influence that the wind causes to crane is heavier and heavier and more and more designing and applying units are paying more attention to this problem.The main form of the rod wind vibration is crosswind vibration, especially the vortex-induced vibration. This kind of vibration is caused by the alternate shedding vortex behind both sides of the rod when wind blow. Besides, in case the vortex shedding frequency is equal to a vibration frequency of structure, the rod will arises the vortex shedding resonance or called vortex resonance.The resonant velocity of wind has directly relation to the structure frequency, and the structure frequency has related to many factors of the rod. The dissertation computed the rod structure frequency different constraints under different axial force and length. To the constraint we can't compute directly, we created the actual model of the fixed tie link in container crane, compute the model's structure frequency and analyses the effect of the axial force and length on the frequency and resonant velocity with the ANSYS, and use ANSYS dynamic module to simulate the rod crosswind resonance.In fact, the cross-section rods are easy to induce wind resonance, especially the vortex-induced vibration; the strong vibration can cause the rod two-end nodal board fatigue cracking. The main measure controlling the vibration is structure vibration control that is fixing some wind interference unit at the surface of rod so that disturb the frequency vortex shelling, and reduce the crosswind vibration force. This dissertation research and analyze the cause of the vibration and the factors influencing their resonant wind velocity, simulate the wind resonancethrough testing, and take some measures to reduce the vibration, such as sample helix interference rib. We contrast the vibration frequency > amplitude and mean square root at the case of no rib> rib with various amount and part distributing rib of the rod, and put forward some other suggestions of vibration control at actual conditions.