Construction And Application Of Two-dimensional Axisymmetric Model Of Electromagnetic Bulging With Field Shaper

Electromagnetic forming technology,as a green and flexible high-speed forming technology,is in perfect agreement with the needs of the times and has significant advantages.In the process of electromagnetic forming,when the resistivity of the workpiece to be processed is too high,the electromagnetic forming technology with magnetic collector is usually adopted;that is,add a collector between the drive coil and the workpiece to be processed to enhance the electromagnetic force of the workpiece to be processed.Based on the working principle of the collector,this paper establishes a three-dimensional model of electromagnetic expansion of the tube parts with a collector,simplifies the threedimensional model into an equivalent two-dimensional model by using a reasonable equivalent principle,and compares and analyzes the simulation results of the three-dimensional model and the two-dimensional model to find that the equivalent two-dimensional model can effectively solve the problem of electromagnetic forming simulation of the magnet with a collector.On the basis of this research,the problem of electromagnetic forming uniformity of plate band magnet is further studied by using the two-dimensional equivalent model of magnet collector,and the problem of uneven plate forming can be effectively solved by magnetizer.Because the geometry of electromagnetic bulging with collector tube is not in line with axisymmetry,the three-dimensional model is usually used to analyze the process,which is complex and has a large calculation amount.Therefore,based on the understanding of the working principle of the collector,a two-dimensional model with current constraint is constructed for the electromagnetic bulging process of the tube with collector.At the same time,three groups of comparison models,including three-dimensional model,two-dimensional model without current constraint and two-dimensional model with current constraint,are established by COMSOL finite element simulation software.The simulation results show that the density of induction eddy current,flux and electromagnetic force body of the twodimensional model with current constraints are in good agreement with the results of threedimensional model,which is an effective way to solve the electromagnetic bulging simulation problem of the tube with magnetic collector.At the same time,the uneven radial deformation of the aluminum alloy sheet is still one of the key problems that restrict the technology.Therefore,the electromagnetic forming technology of coil loaded plate based on the plate collector is proposed.By placing it between the drive coil and the plate,the distribution of the induced eddy current in the plate is changed,and then the distribution of electromagnetic force is controlled to achieve more uniform deformation.In this paper,the electromagnetic structure coupled finite element model of electromagnetic forming of sheet metal is established.The parameters of eddy current,electromagnetic force distribution and forming effect of plate are analyzed.The simulation results show that the radial deformation of the plate can be improved by focusing the axial electromagnetic force near the end of the plate,and the reasonable structural parameters of the collector can make the plate uniform best.In this paper,the uniformity of sheet metal forming is improved obviously,and the maximum uniform deformation area increases from 32.1mm to73.8mm,which has a certain promotion effect on the application of electromagnetic forming in industry.