Elastic-Plastic FEM Simulation On Thin Strip Cold Rolling Process

The shape control problem of thin strip in cold rolling is complicated and difficult to solve. Based on the cooperative project of BaoSteel and Northeastern University, "Studies on mechanism of cold rolling— studies on the effect of original shape on exit shape and measurements of shape control for 1420 mm cold tandem mill", in this dissertation the Elastic-Plastic FEM was used to analyze the thin strip cold rolling process by MSC.Marc software. The static implicit expression of elastic-plastic FEM was utilized to simulate couple field of displacement and stress between strip and rolls, work roll and backup roll. The dissertation will be a worthy reference for the FEM model of rolling process and shape control in practical rolling process. The main studying work and results are shown as following.1) To meet the requirements of different simulation, the rolling model of 2-D rigid roll, 2-D elastic roll, 3-D rigid roll, 3-D elastic roll, 3-D 4-high mill, and the rolls system deformation model of 4-high CVC mill were created. These models were necessary to investigate different thin strip rolling process. Based on the simulation of practical rolling process, the results of simulation agreed well with the measured value, it was shown that these models had high precision and authenticity.2) By applying 2-D elastic roll rolling model and 3-D 4-High rolling model, the rolling force and pressure distribution had been analyzed, and the effect of different rolling conditions on rolling pressure distribution had been discussed, too. It was clearly that the rolling force will be increased 0.25MN while the friction ratio increased 0.01; the rolling force will be decreased 1.2MN while the forward and backward tension increased lOOMPa respectively; the rolling force will be increased 1.25MN while the resistance of deformation increased lOOMPa; the rolling force will increase 0.1MN while the reduction increased 1%.3) Based on elastic-plastic FEM, the effect of rolling condition on strip crown and edge drop, the effect of tension and strip width on strip deformation along strip width had been analyzed. It was found that in the central area of strip, metal would flow to...