The Study Of Numerical Simulation On The Vortex-induced Vibration Of Marine Deep Water Pipe Model

Along with the implementation of ocean strategy of our country,a and the rapid development of the demand of offshore road transport, the sea transport facilities and the demand of the construction of sea-crossing bridge are increasing. Bridge pile foundation in the process of construction and the use of it is often influenced by vortex-induced vibration. The vortex-induced vibration of pile is more and more intense with the increase of water depth and the changing of the complicated flow field.So, the research of vortex-induced vibration of bridge deepwater pile is very important to the construction of the oversea bridge. The main contents and research results of this paper:(1) Try using Abaqus software with the function of the Co-execution of fluid-solid coupling calculation, under the condition of uniform flow and the gradient flow, numerical simulation and research of flow around cylinder, the vortex-induced vibration of steel pipe pile and the vortex-induced vibration of steel pile under the pile-soil interaction have been done.(2) Through the numerical simulation of the uniform flow and gradient flow of flow around cylinder,we can see that: under the laminar flow, vortex behind cylinder generate and diarrhea periodicly.The oscillation of lift and drag coefficient are both stable in a certain fixed amplitude.Wake flow under turbulent flow into turbulent vortex street.At that time,the lift and drag coefficient are relatively stable;Strouhal number is in line with the literature of the experimental results, but at high Reynolds number, they are both in small or large.(3) Through the numerical simulation of the uniform flow and gradient flow of vortex-induced vibration of steel pipe pile,we can see that : by lift and drag coefficient can be seen that, in the different Slenderness ratio and different mass ratio, under the same Reynolds number,the lift and drag coefficient have clear changes, but the change of spectrum is not big,but the stability of these in the gradient flow is better.By the relation of curve of reduced velocity and resonance effect can be found that, under the lower quality, there are more branches in the curve of reduced velocity with two degrees of freedom of dimensionless amplitude after the occurrence of vortex-induced vibration. The change of amplitude and volatility of the curve in gradient flow compared with that in uniform flow are smaller, less Ax branch, the changing rule of the Ay is more unified. Under the condition of gradient flow,the curve of the reduced velocity with frequency ratio compared with the that of uniform flow,lock frequency required less reduced velocity.Through the curve of reduced velocity with frequency can be found that the greater the mass ratio, the more the reduced velocity, when reaching the locked frequency.(4) The vortex-induced vibration of steel pipe pile under the gradient flow and the interaction of pile-soil,compared with vortex-induced vibration of steel pipe pile under the gradient flow, the lift and drag coefficient under different Reynolds number are both more stable. Reduced velocity and resonance effect are more regularly too.But the degree of vortex distribution is weaken.These showed that the soil to the vibration of the steel pipe pile has certain inhibitory effect.