The Theoretical Research Of Three-dimensional Plasticflow In Rail Universal Rolling Process

High-speed railway become the most important transportation means worldwidefor it’s characteristic of safety, high efficiency, environment friendly, low energyconsumption. Rail act as important component in rail structure, it’s section dimensionaccuracy and straightness directly affect railway safety and rail service life.Analytical formula for extension and wide exhibition in the process of railuniversal rolling is applied mainly referring to stripe rolling formula, so the transverseflow of the metal in rolling process between rail head, rail web and rail base, rail web isignored. However, the transverse flow of the metal directly affect the rail longitudinalextension, section dimension and bending after rolling. Therefore, the mechanism oftransverse and longitudinal flow in the process of rail universal rolling must be analyzed,the prediction model of metal transverse flow volume, volume flow rate, longitudinalextension coefficient must be established, thus reasonable rolling schedule can beformulated, such research is theoretically and practically significant for improving railrolling accuracy.Firstly, rational simplification of rolling model is necessitated, the formula of totalrolling power in the process of rail universal rolling is given. On basis of this, extensioncoefficient on condition of minimum power is solved, using genetic algorithms and rigidplastic variational principle that total rolling power is minimum in real velocity field,plus total rolling power as the objective function, extension coefficient of rail head andrail base as optimization factor.Secondly, according to the condition that volume is incompressible and the lengthof contact deformation zone of rail head, rail web and rail base is inconsistent while afterrolling this three parts is a unified whole, the formula for extension coefficient of railhead, rail web and rail base and metal transverse flow volume is solved. On basis of this,the formula of metal transverse volumetric flow velocity is deduced. The curve ofextension coefficient, metal transverse flow volume and metal transverse volumetric flowvelocity is solved on different deformation process conditions by using software MATLAB.Finally, the three-dimensional model of rolled piece and roller is created using3Dmodeling software Pro/ENGINEER, and then the model is imported into finite elementanalysis software MARC, thus the simulation model of rail universal rolling coupledthermal is established, so wide exhibition, extension and metal transverse flow in theprocess of rail universal rolling is obtained after simulation.The theoretical calculation results and rolling simulation results are similar bycomparison, thus the three-dimensional plastic flow of rail universal rolling can bepredicted by the results.