Study On The Dynamics Of The Torsional-horizontal Coupled Vibration System Of The Main Drive Of Rolling Mills

Steel rolling industry is an important support for the realization of industrial modernization in China,however,the nonlinear vibration of the rolling mill has a serious effect on the development of China's steel rolling industry,causing the equipment damage of rolling mill and safety accidents.Therefore,it is of great practical significance to understand the instability oscillation mechanism of rolling mill and to put forward an effective control strategy for rolling mill.In this paper,the main drive system of rolling mill is taken as the research object.Considering horizontal vibration,torsional vibration of rolling mill and other necessary factors,the nonlinear dynamic equation of rolling mill is established.Based on the established model,the relevant theoretical research on vibration characteristics and vibration control is done.The theoretical analyses of vibration mechanism and control strategy are verified by numerical simulation,aiming at promoting the development of the research on the nonlinear vibration of the main drive system of rolling mill in theory and practice.Firstly,considering the coupling effect of horizontal vibration and torsional vibration of the rolling mill drive system,the dynamic equations of the vibration coupling system are established.Secondly,in order to analyze the bifurcation characteristics of the system,the dimensionality of high dimensional coupling system is reduced adopting method of Lyapunov-Schmidt(LS)reduction.The equivalent equation,which has the same dynamic law with the original system,is obtained.The study on the topology of static bifurcation is researched by using the principle of singularity,and the parameter range making the system stable is obtained,which provides a theoretical reference for the further study on the vibration of the rolling mill drive system and the design of the structural parameters.Finally,the equilibrium point of the coupling vibration system of rolling mill is analyzed by matrix and criterion.Choosing the mixed friction coefficient as Hopf bifurcation parameter,the specific changes of the system's bifurcation is analyzed.In order to verify the correctness of the theoretical research,the actual parameters are used as simulate the datum.The Wash-out-filter controller is introduced to realize the bifurcation control of nonlinear system of rolling mill.And the transformations of bifurcation point position,type and so on are realized by the usage of the controller,which provides a theoretical reference for the instability control of rolling mill.