Research On The Natural Vibration Characteristics And Flow Induced Vibration Of The Radial Gate Pier System

Radial gates are widely used in water conservancy projects due to their advantages such as being able to close large orifices,low opening and closing force,and no gate slots.They are usually used as working gates and are the regulating structures of water conservancy projects.The safe operation of radial gates is an important guarantee for the comprehensive benefits of water conservancy hubs.The radial gate and gate pier are closely connected and interact with each other under the fluctuating pressure of water flow,forming a system.This article uses ANSYS to establish a model of the radial gate pier system,studying the influence of the pier on the dynamic characteristics of the radial gate and the mutual influence of the dynamic response between the radial gate and the pier.Based on this,the influence of the arm arrangement on the dynamic characteristics and response of the radial gate pier system is studied,and the optimal design scheme is selected by comprehensively considering the dynamic characteristics of the radial gate and the distribution law of the dynamic response of the gate and pier,Provide a new approach for the safety evaluation of radial gates and gate piers.The main research content and conclusions of this article include:(1)The model of the radial gate pier system is established,calculate the dynamic characteristics of the radial gate,study the influence of the pier on the natural frequency and vibration mode of the radial gate,and the influence of gate opening on the natural frequency of the radial gate.The results show that the gate pier has a significant impact on the vibration mode of the radial gate arm and panel.Considering the influence of the gate pier on the reduction of the natural frequency of the radial gate,the water body has a significant impact on the dynamic characteristics of the radial gate.The fluid structure coupling effect cannot be ignored when calculating the natural vibration characteristics of the radial gate.(2)On the basis of spectral analysis of the fluctuating pressure of the radial gate water flow,the power spectrum curve of the fluctuating pressure is obtained using Fourier transform.The results show that the closer the panel measurement point is to the bottom,the greater the root mean square and dominant frequency of water flow pulsation pressure;The larger the opening of the radial gate,the greater the root mean square and dominant frequency of water flow pulsation pressure.(3)The dynamic response of the radial gate is calculated.,analyze the distribution of dynamic displacement and stress of the radial gate.The results show that the pier has a significant impact on the panel and support arm of the radial gate.The maximum displacement of the panel along the river decreases by 44.58%,and the maximum decrease in Mises stress is 41.70%;The maximum displacement of the support arm along the river increases by 37.93%,and the maximum increase in Mises stress is 30.71%;The impact of the gate pier on the main crossbeam and longitudinal beam of the radial gate is relatively small.(4)Consider the flow induced vibration of the radial gate,calculate the dynamic response of the gate pier,and compare it with the calculation results of the dynamic coefficient method.The results show that both calculation methods have the maximum stress in the vertical flow direction of the bracket.When the dynamic coefficient is 1.2,the maximum stress in the bracket is 8.50 MPa.Considering the flow induced vibration of the radial gate,the maximum stress in the bracket is 8.30 MPa,which is 2.35%lower than when the dynamic coefficient is 1.2.(5)This paper propose five different arrangement forms of support arm truss,calculate the dynamic characteristics and response of the radial gate,and consider the stress of the bracket under flow induced vibration of the radial gate,and comprehensively select the optimal arrangement form.The results show that the 3#support arm truss form can effectively reduce the dynamic displacement of the radial gate,avoid severe vibration of the radial gate,and ensure the safe operation of the radial gate.The research results of this article can provide reference for numerical simulation and safety evaluation of dynamic problems of radial gates and gate piers.