Mathematical Modeling And Simulation On Strip Shape Control Of Four Rollers Cold Rolling Mill Based On Roll System Elastic Deformation

The research object of this paper is the strip shape of four rollers cold rolling mill,the impact factors of strip shape and the basic theory about strip shape control of rolling mill have been studied.A basic theory of strip shape control of rolling mill is the roll system elastic deformation,it is especially necessary to build a mathematical model about the roll system elastic deformation based on the roll system elastic deformation theory and method about strip shape control,combined with the advantage of finite element simulation software to carry on finite element simulation analysis about the rolling process.Finally,verify the accuracy of the mathematical model and finite element model via experiment.The main contents of this paper are as follows:(1)First,the mathematical models of roll system elastic deformation were set up with influence function method,as the mathematical model about flattening between rolls can not be set up with influence function method,simplify it to be an elastic half-plane problem,the calculation has been reduced and the engineering needs have been satisfied,the model has been established,using integral method to calculate the deflection of the work roll and backup roll.(2)Next,in order to analysis the shape control capability of four rollers rolling mill,selecting the sheet width and bending force as two factors to calculate based on the mathematical models of roll system elastic deformation and related parameters,the results were showed in graphical form intuitively.Then the mathematical model about the relationship between the bending force with the plate crown has been established under some assumptions,making a conclusion that the plate crown changes linely with the bending force through calculation.(3)And then based on the mathematical models,taking advantage of the powerful simulation analysis capabilities of the finite element software,a finite element model about rolling process of four rollers rolling mill has been built.Dynamic simulation analysis about the rolling process and the roll system elastic deformation have been carried on.The influence on strip shape of various factors such as strip width,reduction,front and rear tension,the diameter of work roll and backup roll,the crown of work roll and backup roll,the work roll bending have been analyzed.Getting the stress strain diagram and equivalent stress diagram when some factors have changed,then given the comparative analysis between the results of the finite element model and the mathematical models,it validated the reliability and validity of the mathematical model and finite element model.Finally fit the curves of each factor and strip crown according to the finite element analysis result.(4)Taking a four-high reversing cold rolling mill of a domestic enterprise as the test object,obtaining the measured data about the relationship between the influence facts with the plate crown through experiments.Then the test results and the results of the mathematical model and finite element model were compared,their goodness of fit is great,it proving that the mathematical model and finite element model is accurate and reliable,The resulting conclusions have a certain reference value for actual production.