Study On Vertical-horizontal Coupling Vibration Control Mechanism Model And Characteristic Of Rolling Mill Rolls

The vibration of the rolling mill is always one of the concerning technical problemsin iron and steel industry, the vibration of the rolling mill rolls frequently happens in theproduction, so it can lead to increase wear and tear of the roll and strip surface appearslight and dark stripes, which reduces the quality and precision of the rolled products,which even makes damage to rolling equipment. Therefore need urgently to understandthe reasons for rolling mill vibration, grasp the vibration mechanism and propose thepossible ways to effectively suppress and eliminate vibration mill.Firstly, this research takes the rolling mill as the study object, considering that thevertical and horizontal vibrations of the mill are mutually affected and mutually coupled inthe actual production, and taking into account the factors such as rolling mill structure,nonlinear stiffness, nonlinear damping, tension fluctuation, changes in the externalexcitation and so on to establish three kinds of vibration models, which are based on thedynamic rolling process, the variable friction and the vertical-horizontal couplingvibration control mechanism mode of the multiple degree of freedom rolling mill.Secondly, using multiple-scale method to solve approximate solution of the rollingmill in the vertical-horizontal coupling control models which is based on dynamic rollingprocess and variable friction, so obtaining the amplitude-frequency characteristic equation.On this basis using the singularity theory to obtain the primary resonance of the coupledsystems under dynamic rolling process and the bifurcation response equation under thevariable friction. Applying the harmonic balance method to give the amplitude frequencyresponse equation of the multiple degree of freedom mill rolls in the vertical-horizontalcoupling nonlinear vibration control model.Thirdly, based on singularity theory to study the static bifurcation characteristics ofthe primary resonance under the dynamic rolling process and the coupling system underthe variable friction, and obtaining the transition sets of the system under the differentparameters and topology of the bifurcation curves in different regions. So it can get theprocess parameter region which leads mill to instability. Taking the actual parameters of the mill for example, applying the simulation to study the affection of the differentnonlinear parameters on the amplitude-frequency characteristics of types of vibrationcontrol mechanism model, which reveals characteristics and the law of the coupledvibration system of the rolling mill.Finally, using the numerical simulation to analysis the dynamic bifurcation and chaosmotion phenomena of vertical-horizontal coupling vibration system in the dynamic rollingprocess and multiple degree of freedom mill rolls, and using the phase plane plots,Poincare maps and top Lyapunov exponential maps to verify the evolutionary path ofchaotic motion, which provides a theoretical basis for researching the coupling vibrationmechanical characteristics of the rolling mill and suppressing the mill vibration in thefuture.