整辊式板形仪波形演变机理

Waveform evolution mechanism of whole roller flatness meter

在整辊式板形仪试验调试和工业应用中发现,大包角和大张力的情况下,板形辊内部传感器会输出明显区别于常规单峰波形信号的双峰波形信号。板形辊变包角安装时,存在着单峰波形向双峰波形过渡的情况,甚至在不同检测通道中,存在单、双峰波形共存的现象。由于双峰波形从形式上明显不同于单峰波形,如果按照常规单峰信号处理方式处理这种波形信号会产生明显板形检测误差。为了研究波形演变的原因和规律,设计了四辊变张力、变包角计算模型,并将其应用于有限元仿真计算。结果显示,大张力和大包角是板形仪输出信号中产生双峰波形的主要影响因素。在特定张力的条件下,单峰波形会随着包角的增大而逐渐演变为双峰波形;在特定包角条件下,单峰波形又会随着张力的增大而逐渐演变为双峰波形。为了进一步研究波形演变机理,在20°、30°和40°包角下,分别固定施加在板形辊单通道上的张力进行仿真计算,提取了传感器安装孔顶和两侧面的位移变化,得到了波形关键位置对应带材与辊体相对位置的传感器顶面位移变化。分析发现,传感器安装孔轮廓在大张力、大包角下会产生不规则的微变形,使得传感器受力状态和位移趋势发生改变,从而产生单、双峰波形信号演变的现象。通过搭建试验平台进行了等张力变包角试验和等包角变张力试验,还原了仿真波形曲线演变规律,验证了其结果的正确性。最后,分析了仿真波形曲线与实际波形曲线差异的产生原因,并针对如何避免双峰波形对整辊式板形仪检测带来的影响给出了具体建议。

It is found in the test debugging and industrial application of the whole roller flatness meter that under the condition of large wrapping angle and large tension,the sensor inside will output the double peak waveform signal which is obviously different from the conventional single peak waveform signal.When the flatness meter is installed at variable wrapping angle condition,there is a transition from single peak waveform to double peak waveform and there is even a coexistence of single and double peak waveform in different detection channels.Since the shape of the double peak waveform is obviously different from that of the single peak one,obvious flatness detection error will be generated if the waveform signal is processed by conventional signal processing method.In order to study the cause and law of waveform evolution,a four rolls model of variable tension and variable wrapping angle was designed and applied to the finite element simulation.The results show that large tension and large wrapping angle are the main factors affecting the double peak waveform in the output signal of the flatness meter.The single peak waveform will gradually evolve into the double peak waveform with the increase of wrapping angle under certain conditions of tension and the single peak waveform will gradually evolve into double peak waveform with the increase of tension under the condition of specific wrapping angle.In order to further study the evolution mechanism of the waveform,the tension fixed on the single channel of the detection roll and it was simulated under the 20°,30°and 40°wrapping angles,respectively.The displacement changes of the top and two sides of the sensor mounting holes were extracted,and the displacement changes of the top surface of the sensor corresponding to the relative position of the strip and the roll body were obtained.It is found that the profile of the mounting hole of the sensor will produce irregular micro-deformation under large tension and large wrapping angle,which changes the stress state and displacement trend of the sensor,resulting in the evolution of single and double peak waveform signals.By setting up a experimental platform,the constant tension variable wrapping angle test and constant wrapping angle variable tension test were carried out.The evolution law of the simulation waveform curve was restored and the correctness of the results was verified.Finally,the reasons for the difference between the simulated waveform curve and the actual waveform curve are analyzed,and specific suggestions are given on how to avoid the influence of double peak waveform on the detection of the whole roller flatness meter.