The Deformation Mechanism Analysis Of The Roll Forming Process For Ultra High Strength Steel

Roll forming technology can obtain better products which have high strength,better quality and high precision and has been widely used in many fields,such as automobile and architecture.In this paper,the deformation mechanism of roll forming for ultra high strength steel was studied by means of analytic method,finite element simulation and experiment.In this paper,ABAQUS finite element simulation model of roll forming for ultra high strength steel was established.The accuracy of the finite element model was verified by comparing the final section size of the experimental parts and simulated parts.Considering the influence of the longitudinal bending strain on the ultimate longitudinal strain,the longitudinal strain of roll forming parts for ultra high strength steel was analysed,the formula of longitudinal strain was revised through numerical simulation and experimental results.The simulation and experimental results show that the error of the longitudinal strain and the longitudinal strain obtained by the analytical calculation is 5E-4.The deformation mechanism of roll forming was expounded.Roll forming is a process which the sheet is subjected to loading-unloading forces repeatedly.The equivalent stress of the sheet is released periodically after passing through each roller.Therefore,the springback of roll forming part is caused by incremental releasing elastic stresses on multiple passes,and the final forming of the sheet is the result of cumulative plastic strain of multiple passes.In order to analyse the springback phenomenon of roll forming parts for ultra high strength steel,stress and strain fields at angle of sheets were analysed under the two types of roller design.The results show that the bending can effectively increase the plastic deformation in the bending zone,increase the equivalent plastic strain value,and improve the accuracy of the roll forming parts.The thickness of the sheet in the bending area of the parts is obviously improved,so that the material flow in the angle of the sheet is more reasonable.The forming accuracy of the parts was compared under different roller design,the maximum error of springback angle is 1.66%.