机组水平动荷载对机墩振动反应的影响

Analysis of the Effect of Mechanical Horizontal Dynamic Load on Vibration Response of Generator Pedestal

水电站发电机组运行时将产生激振力,机墩作为发电机组主要支撑部位,其发生的振动现象较厂房结构其他部位明显。通过建立某水电站地下厂房三维有限元模型,采用谐响应法进行动力计算,研究实际工程中在不同机组水平动荷载施加方式下机墩各典型部位振动反应的分布规律。分析结果表明,机组水平动荷载的施加方式对机墩部位的振动影响很大,应根据机组动荷载的实际特性选取合适的施加方式才能充分考虑机组振动时产生的不利影响。

Sorts of exciting force will be generated when hydraulic turbine-generator units are operating.Given that generator pedestal is the main supporting part of unit,exciting force directly manifest loads in various directions acting on foundation,so the vibration of generator pedestal is more obvious than other parts.Establishing three-dimensional finite element model of the underground powerhouse,dynamic cal-culation was applied by using harmonic response method.This paper primarily researched vibration responses of each typical part of generator pedestal under different exerting mode of mechanical horizontal dynamic loads in actual engineering.The result shows that the exerting mode of mechanical horizontal dynamic loads greatly affects the vibration of generator pedestal.According to the practical characteristic of mechani?cal dynamic loads,appropriate exerting mode is suggested to be adopted to take full account of adverse effect produced by vibration of unit.