贵阳市南明河气动盾形闸门结构自振特性分析

Analysis of Natural Vibration Characteristics of Pneumatic Shield Gate Structure in Nanming River of Guiyang

气动盾形闸门结构属于空间结构,在动水运行中存在振动现象。由于闸门所处水流状态、边界条件和受力情况复杂,其振动机理也相当复杂。当闸门振动时,附近流场将产生流体惯性力、阻尼力、弹性力,并反作用于闸门,使得结构的质量、阻尼、刚度发生变化,从而导致结构振动特性发生变化,其中结构振动引起流场变化而产生的对结构反作用的流体力对结构振动特性有很大的影响。通过对南明河气动闸门采用有限元模型模拟,结果表明:当闸门处于挡水工况下,由于水流产生脉动压力作用于闸门,当水流脉动压力的主频率与闸门自振频率接近时,会发生共振现象,对闸门的自振特性进行分析,弄清产生共振的机理,可有效避免共振发生。

The pneumatic shield gate structure belongs to the space structure,and there is vibration phenomenon in the running water operation.Due to the complicated water flow state,boundary conditions and force conditions of the gate,the vibration mechanism is also quite complicated.When the gate vibrates,the nearby flow field will generate fluid inertial force,damping force,elastic force,and react to the gate,so that the mass,damping and stiffness of the structure change,resulting in structural vibration characteristics,wherein the structural vibration causes the flow field The fluid force that reacts to the structure and has a great influence on the vibration characteristics of the structure.Through the finite element model simulation of the Nanming River aerodynamic gate,the results show that when the gate is under the water retaining condition,the pulsating pressure of the water flow acts on the gate.When the main frequency of the pulsating pressure of the water flow is close to the natural vibration frequency of the gate,it will occur.The resonance phenomenon analyzes the natural vibration characteristics of the gate and clarifies the mechanism of resonance,which can effectively avoid resonance.