Research On The Mechanics Parameters Model In Strip Cold Rolling Process

The prediction precision of mechanics parameters such as rolling force and rolling torque affect the yield,quality,cost and benefit of products during the thin strip cold rolling.According to data of the five-stand tandem cold rolling mill in Tangshan Science and Technology Company,the ANSYS-LSDYNA finite element model is used to simulate the strip cold rolling process,and the BP neural network model is constructed.The mechanics parameters model is researched base on these models,and it is significant to predict mechanics parameters in actual production.The main work is as follows:(1)The mathematical models of the cold rolling process are described in detail,including the deformation resistance model,the friction coefficient model,the roll flattening radius model,the rolling force model,the rolling torque model,the motor power model and the mechanical loss power model.The relationship between rolling force and rolling torque is analyzed.(2)The strip cold rolling process is simulated by the elastic-plastic finite element and dynamic explicit algorithm and a three dimensional model of the two rolls is established.The finite element modeling process including the control of hourglass,the formulation of mass scaling strategy,the selection of rolling process parameters during simulation calculation,the establishment of three-dimensional geometric model of roll and strip,the selection of mechanical properties,the choice of element type,the partition strategy of simulation model mesh,the definition of contact type and algorithm,the application of constraint condition and force load and the setting of solving parameters.(3)The simulation results obtained by the finite element model are in good agreement with the actual production data.The influence of rolling parameters on the rolling pressure distribution in the deformation zone is simulated by single factor alternate method.The changes of rolling force and the rolling pressure with different forward tension,backward tension,reduction,friction coefficient,and deformation resistance are studied.The formula for calculating the rolling torque and the arm factor using the rolling pressure distribution between the strip and the roll is given.According to the simulation results of finite element,the variation law of the arm factor under different tension,backward tension,reduction,friction and flattening radius are studied respectively,and then a fitting formula of arm factor is proposed.(4)The BP neural network model is constructed and the training data are collected and processed.The trained data are compared with the input sample data,and the deviation can meet the requirements.The formula of arm factor is amended and applied to solve the rolling force based on energy method.Compared with the rolling force calculated by Tselikov,Hill and Stone models,the results of the energy method in this paper is in good agreement with other models.