Study On Fluid-Solid Coupling Vibration Characteristics And Stability Of Plane Steel Gates

Water is the source of life,the foundation of ecology,and the key to production.Water conservancy project is an important infrastructure in China.With the construction and development of high-dam reservoirs at home and abroad,the hydraulic steel gates that regulate the throats as water-discharging and water-conserving projects are facing large heads with high heads,large orifices and large discharges.The development of lightening and lightening,its safe and flexible operation determines the safety of the entire hub project and the lives and property of the downstream people.The gate is one of the important components of the hydraulic structure.It is an active structure for closing the orifice and adjusting the opening of the orifice.It is used to block water and adjust the upstream and downstream water level and the flow of the gate according to actual needs.In hydraulic engineering,the problem of gate vibration has been difficult to solve for a long time.The vibration of hydraulic gates is the root cause of the destruction of most hydraulic structures.Due to the complexity of its structure and working conditions,it has many safety and stability problems in engineering operation.Based on the problems existing in the actual project,this paper combines the spillway gate project of Lingshantou Reservoir in Linyi County,Linyi City,Shandong Province,to study the self-vibration characteristics and the effect of water flow pulsation on the plane steel gate under fluid-solid coupling.Analysis and numerical simulation are combined.The main research contents are as follows:(1)According to the finite element theory,the finite element numerical calculation method is used to calculate the dynamic characteristics of the gate,and the basic equation of motion is established.The dynamic pressure in the flow field and the dynamic pressure on the contact surface between the fluid and the structure are calculated.At the same time,the gate structure is discretized,and the eigenvalue and eigenvector of the structure are solved by the finite element method,that is,the natural frequency and mode shape of the gate structure.(2)The finite element model of the coupling between the gate and the water body is established by the finite element analysis software ANSYS.According to the software calculation,the natural vibration characteristics and vibration modes of the gate structure under different opening degrees are analyzed under the condition of water and water,and the gates are analyzed differently.The law of self-vibration characteristics.At the same time,a series of changes in the characteristics of the door body when the gate is subjected to the impact of the water flow are simulated,and corresponding conclusions are drawn.The results show that with the increasing degree of gate opening,the water level on the water surface of the gate is continuously reduced,the natural frequency of each step of the gate increases,and the vibration modes of each step also change.When the gate is affected by the impact of the water body,the law of pressure change,elastic deformation and mechanical deformation of the gate are roughly similar.(3)According to the vibration characteristics of the plane steel gate,and summarizing the previous research experience,a series of anti-vibration measures and stability optimization schemes are proposed.According to the engineering example,the gate structure damper is reasonably arranged to avoid or mitigate the gate damage caused by the harmful vibration.Through theoretical analysis and finite element numerical simulation,comparative analysis,the corresponding optimization scheme is proposed to improve the stability of hydraulic gate operation for practical engineering reference,so as to design a gate with less harmful vibration.