高频机组基础振动检测分析

为了找出诱发高频机组基础不良振动的原因，从基础计算模型方面对基础激励与响应进行了分析，以两个高频机组基础为动测实例，经模态分析得出钢筋混凝土构架式基础竖向1阶振动与电机产生共振；应用功率谱法对动力机组及基础平台进行动测，得出平台异常响应频率66Hz为水泵工作频率，调整机器的工作频率可避开不良振源影响，达到明显的减振效果。由此而知，动力机器基础出现不良振动时，不可盲目改变结构的动力特性，应在机器不同工况比如：停机、起机及正常转速下，对机器及基础进行动测并对振动信号进行比较分析，以制定出行之有效的减振方法。

Analysis of monitoring of vibration of foundation of high-frequency dynamic machines

In order to find the reasons for harmful vibrations of dynamic machine foundations , factors are discussed in such respects as calculating models, stimulation and response, then two vibration detection engineering examples are introduced. By modal shape analysis, it's found that some reinforced concrete(R.C) frame foundation rebounds in order vertical vibration with the motor , and by power spectrums and it's found that the abnormal response frequency of a certain R.C mass foundation is 66Hz at which the water pump works. The bad effect of vibration can be avoided by adjusting the machine frequency. When dynamic machine foundations have bad vibrations, one of the best ways of reducing the bad vibration is the monitoring for the dynamic machines and its foundations under different work states such as working break, rotation initial stage and rotating at specific speed, and analyzing the signal thoroughly and comparatively, instead of changing the structural dynamic characteristics blindly.