非线性动态轧制力作用下板带轧机垂直-水平耦合振动机理及特性研究

The vibration of strip mill roll could cause strip surface stripe and roll mark, which always restrict the enhance of rolling speed and accuracy of products. At present, most of the study of vibration in vertical and horizontal directions are separately, and always ignore the coupling relationship between horizontal and vertical direction force in the workpiece deformation zone. In this project, the influence of roll’s vertical and horizontal vibration roll in the workpiece deformation processing will be considered, and the nonlinear dynamic rolling forces in vertical and horizontal direction will be obtained based on the OROWAN force balance theory, then the vertical - horizontal coupling nonlinear vibration model will be obtained. The nonlinear system analytic solution will be solved by homotopy analysis method, and amplitude-frequency curve can be constructed, then the resonance region of strip rolling mill are obtained. At the same time, the center manifold method, normal form theory will be used to system dimensionality reduction processing, then the singularity theory will be applied to analyze the bifurcation behaviors, so the bifurcation in different vibration state and regions and instability vibration of the critical condition can be obtained. Finally, the zone of technology parameters in instability vibration can be found through the analysis of the relationship between process parameters and the instability critical condition.This project will promote the development of the theory of rolling mill vibration, and will show a effective way to select the process parameters and structure parameters from the aspects of avoid vibration.

板带轧机轧辊振动是造成板带材表面条纹、辊面印痕的主要原因，一直是限制轧制速度和产品精度进一步提升的技术难题。目前大多将轧辊垂直和水平方向振动分开研究，忽略了轧件变形区水平和垂直方向作用力耦合关系，研究内容和解决方法非常有限。本项目考虑轧辊垂直和水平振动对轧件变形过程的影响，基于OROWAN力平衡理论得到垂直和水平方向的非线性动态轧制力，在此基础上建立板带轧机垂直-水平耦合非线性振动模型。采用同伦分析法求解该非线性系统的解析解，得到不同轧机结构参数和轧制力非线性参数下的幅频特性曲线，从而找出系统的共振区域。同时运用中心流形、范式理论对系统降维处理，再采用奇异性理论得到系统出现不同振动状态的分岔条件及失稳振动的临界条件。通过分析工艺参数与失稳临界条件的相互关系，得到失稳振动的工艺参数区域。项目完成后将推动轧机振动理论的发展，并从避免振动角度为工程中轧机工艺参数和结构参数的选取提供有效途径。

为进一步减少板带轧机轧辊振动问题，提升轧制生产速度和轧制产品精度。本项目基于OROWAN力平衡理论建立了含有振动因素的垂直和水平方向的非线性动态轧制力，为进一步更准确计算振动情况下的动态轧制力提供理论计算公式。同时考虑动态轧制力和轧机机械设备振动之间的耦合关系，建立板带轧机垂直-水平耦合非线性振动模型。通过求解该非线性振动系统的解析解，得到不同轧机结构参数和轧制力非线性参数下的幅频特性曲线，找出这些参数对轧机共振频率区域的影响规律。然后采用奇异性理论，得到轧机出现不同振动状态的分岔条件及不稳定(失稳)振动的临界条件，并通过数值仿真分析了轧制力非线性参数以及机械参数对分岔行为的影响规律，找出这些参数与轧机出现各种不同振动行为的相互关系。最后，通过现场实验数据，进一步验证了研究项目的部分理论成果。该研究成果为准确计算振动情况下动态轧制力，以及进一步控制轧机的垂直-水平耦合振动行为提供了理论参考方法。