Vibration Characteristics Analysis And Suppression Of Cold Strip Mill

In recent years,the steel industry has higher and higher requirements on the quality requirements and rolling speed of rolled products.Then the vibration problems of rolling mills are more and more complicated,which is more and more complicated,mainly due to the vertical vibration of the rolling mill frame,the roll system and the rolling direction and the torsional vibration formed by the connecting shaft and the roller system in the main drive system.The vertical vibration and the torsional vibration are not separately present and are coupled to each other.The vibration problem of the rolling mill causes the occurrence of light and dark stripes on the surface of the plate.When the vibration is severe,it is easy to cause a major accident.Therefore,analysis and suppression of the vibration characteristics for the rolling mill has become an urgent problem to be solved.In this paper,the characteristics analysis and vibration suppression of the rolling mill vertical and vertical coupling system are studied.The main contents are as presented follows:Taking the cold rolling mill as the research object,the dynamic rolling force model including the roll gap friction was established,and the elastic deformation of the roll was considered.Based on the Bland-Ford-Hill rolling force,the elastic flattening radius and rolling of the roll were carried out.The force is decoupled and analyzed,and the relationship between the vibration displacement and the variation of the rolling force is obtained.In order to study the influence of the friction and tension between the roll gap of the vertical vibration system of the rolling mill on the nonlinear vibration characteristics of the cold rolling mill,a four-degree-of-freedom nonlinear vertical vibration model considering the friction and tension of the roll gap was established.Because the vibration problem of the rolling mill is not unique,at the same time,the vertical-torsion coupled vibration model of the rolling mill is established,and the vibration equation of the coupled system is obtained.According to the vertical vibration model established above,the time-delay feedback control and multi-scale method are combined to solve the main common amplitude-frequency characteristic equation of the system.The effects of different rolling parameters and tension on the vibration amplitude are simulated and analyzed.The simulation results show that the roll gap friction and tension.It has a great influence on the vertical vibration of the rolling mill,and the jumping phenomenon of the vibration system can be eliminated by appropriately adjusting the time lag parameter.Finally,the stability of the system is analyzed by using the singular point stability theory.The relationship between the friction and tension of the roll gap,the stability of the system,the stability interval are obtained.Finally,according to the solution of the coupled vibration equation of the rolling mill,the multi-scale method is used to solve the main resonance response equation of the system,and the influence of the parameters such as stiffness,damping and external disturbance on the vibration amplitude is analyzed.Finally,by using the reverse The decoupling and sliding mode controller methods are simulated.The results show that the decoupling method and the sliding mode controller have good results.