事故闸门爬行振动数值反演与影响因素分析

Numerical inversion of creeping vibration of emergency gates and its influencing factors

为研究事故闸门爬行振动特征和影响因素,基于原型闸门闭门过程中的振动响应,分析闸门振动特性,确定振动类型。通过类比摩擦学中的干摩擦自激振动,建立事故闸门闭门过程中的振动数值模型,反演闸门振动响应过程,探究闭门速度、闸门质量和摩擦系数等因素对闸门振动的影响。结果表明,事故闸门爬行振动是一种特殊的自激振动,其振幅随闸门开度减小而逐渐增大。闸门与轨道间的动静摩擦转化是引起爬行振动的最根本原因,振动响应强度与面板水推力和动静摩擦系数差值成正比。闭门速度对振动影响较大,存在临界闭门速度,可用于区别闸门是否出现爬振,且临界闭门速度与静摩擦系数有关。闸门质量影响钢绳索初始变形量和闭门时间,进而对爬行振动产生影响。闸门下落闭门,钢绳索长度增加,系统刚度减小,导致振幅和周期增大。

To study the phenomenon and influencing factors of the creeping vibration of an emergency gate,this study examines the vibration characteristics and determines the vibration type based on the prototype gate vibration response during gate closing operation.By analogy with dry friction self-excited vibration in tribology,we develop a mathematical model of closing stage vibration to invert the gate vibration response,and examine the influences of closing speed,gate mass,friction coefficient on the vibration behavior.The results show the creeping vibration of the gate is a special type of self-excited vibration with its amplitude growing gradually during gate closing.Transformation between dynamic and static friction of the gate and its tracks is the fundamental cause of creeping vibration,and the intensity of vibration response is proportional to panel water pressure and the difference between dynamic and static friction coefficients.Gate closing speed imposes great influence on gate vibration;a threshold closing speed,depending on the static friction coefficient,has been observed for judging the creeping vibration mode of the gate.Gate mass affects the initial deformation of steel ropes and the closing time,and thus influences the creeping vibration.The closure of the gate increases the length of steel ropes and decreases the system stiffness,leading to an increase in amplitude and period of vibration.