辊缝位移传感器是轧机压下控制系统(Automaticgaugecontrol,AGC)的关键元件,也是轧机AGC控制系统的反馈环节之一。辊缝位移反馈信号受传感器结构动态特性的强烈影响,传感器结构设计不合理甚至危及轧制过程的稳定性。模态参数可以完整地描述结构的动态特件,在结构动态设计和结构动力学修改阶段,必须进行有效的动态特件分析。采用单点激励、多点加速度响应拾振,对热连轧机辊缝位移传感器的外壳和位移传递杆结构进行了振动测试。以试验模态分析理论为基础,使用最小二乘复指数泫(Leastsquarecomplexexponent,LSCE),提取传感器结构的模态参数。分析结果表明,传感器外壳的垂直振动模态频率与热连轧机架的垂直振动模态频率接近,会对轧机工作机座的振动形成耦合,其动态特性对轧制过程的稳定性有严重危害。这些分析结果对建立轧机压下控制系统仿真模型以及进行结构动力学修改都具有重要意义。
The roller gap displacement sensor is the feedback link of automatic gauge control (AGC) system. The feedback signal of roller gap displacement is subjected to the intense influence of dynamic characteristic of sensor structure, even endangers the stability of the rolling process. The modal parameters may describe the structure dynamic characteristic completely. Therefore, in the phase of the structure dynamic design and the structure dynamics modification, effective dynamic analysis must be carried out. Vibration test of the roller gap displacement sensor structure is carried out by using the one-point excitation and multi-point acceleration response. Based on the experimentation modal analysis theory, the modal parameters of the sensor structure are extracted by using the least square complex exponent (LSCE) method, and the analysis result is discussed. It indicates that the vertical vibration modal frequency of sensor crust is close to the vertical vibration modal frequency of the hot rolling mill stand, forming vibration coupling to the rolling mill stand, whose dynamic characteristic will jeopardize the stability of the rolling process. The analysis results have important significance in establishing simulation model of the rolling mill press down system as well as in carrying out structure dynamics modification.