Research On Multipass Rolling Of Plate With Longitudinal Rib

The plate with longitudinal rib is a type of plate with a variable cross-section thickness,which is widely used in a series of important industrial fields such as automobiles,ships,railways,and bridges.The traditional rolling process can no longer meet the needs of the market,and new rolling processes need to be used to produce various profiled plates,which can improve the overall performance and production efficiency of the plate.Regarding the method of manufacturing special-shaped plates,the main processing methods are additive and subtractive manufacturing.The additive processing processes include welding,and the subtractive processes include milling.The structure of the obtained shaped parts is uneven,and the plate structure is prone to defects,and the forming performance is poor,so it cannot meet the needs of high performance.Through plastic processing methods such as rolling,the performance of the formed parts can be effectively improved,and the processing links of additive and subtractive materials can be reduced.The utilization rate of materials can be improved,and the production efficiency can be improved.This paper proposes a multi-pass rolling forming process for the plate with longitudinal rib.The theoretical analysis and calculation of the rolling process and the finite element simulation analysis of the rolling process parameters are carried out by establishing a mathematical model.The influence rule of the method is obtained,and the forming limit of the convex rib is obtained,and the mold is designed for experiments.The theoretical research is mainly based on the metal flow characteristics of plate rolling to establish a mathematical model during the rolling of profiled plates.The metal flow in the rib area and the theoretical calculation formula for the height of the rib that is half of the reduction when the energy is minimum are specifically analyzed.The maximum error of the theoretical and experimental results is 17.3% and the influence of the groove on the rolling force is analyzed according to the theoretical formula.The reason for the formation of the rib is that the metal at both ends of the plate is deformed by deformation,and the metal in the groove is not deformed by the depression and remains in the groove to form the rib.The research on the pre-rolled forming process of the plate with longitudinal rib is through the finite element simulation software Abaqus,the lower roll was designed as a curved convex structure,and the upper roll was designed with a groove.The metal can flow in the upper roll groove under the action of the arc-shaped convex structure of the lower roll,which greatly improves the filling effect of the groove.It analyzed the different roll profile structures(including the width of the upper roll profile,the inclination of the side wall and the transition fillet,the height and width of the arc-shaped convex structure of the lower roll,and the roller diameter),and the reduction of the rolling passes that impact on the growth of rib.And through the data analysis to obtain the optimal parameters,it obtained the best process for the plate with longitudinal rib.The research on the forming process of the plate with longitudinal rib in the last pass is to design the roll group of the first pass to be shaped with a groove on the upper roll and a convex structure on the lower roll;In the second pass,the upper roll is designed as a groove of the same size as the first pass,and the lower roll is designed as a flat roll.Using this multi-pass rolling method can effectively promote the flow of metal in the upper roll groove and promote the growth of the ribs.Through Abaqus finite element simulation it analyzed the rolling process of the plate with longitudinal rib,the influence of the roll structure on the rib height and the rib raised ratio and the forming limit of the ribs with different plate thicknesses were analyzed.So that it obtained the better forming process parameters.At the same time,the influence of rolling pass distribution on the height of rib was analyzed,and the forming effect of convex rib was improved.Finally through experimental research verification,it compared with the original single-pass rolling forming process in which the lower roll is only a flat roll.The rib height obtained by rolling in the new process is increased by 50%,and the forming effect is better.Thus,the feasibility of the rolling process is verified,and it provides a theoretical basis for the rolling of profiled plates in the future.