The Finite Element Analysis Of The Electromagnetic Tube-compression Process

Since the21st century, the development of science and technology changes with eachpassing day, people for the requirements of the product’s performance and itsmanufacturing method is becoming more and more strictly. So is the mechanicalprocessing industry, low cost, high performance, no pollution become the target of pursuit.In order to effectively reduce pollution and energy consumption, light weight materialsand structural design become the main trend of modern manufacturing. The lightweightmetal material like aluminum alloy has been used widely in the manufacturing field.However, the aluminum alloy has poor formability and low stiffness at room temperature,using ordinary stamping process prone to tear, serious rebound and distortion occurredafter unloading. It is difficult to meet the precision requirements of the parts.Electromagnetic forming is a new kind of forming method with high energy and highforming velocity, by which the metal is loaded under strong impulse magnetic field anddeformed plastically. When forming at high speed,the mechanical properties of materialscan be greatly improved, it is one of method that aluminum alloy parts is shaped by theelectromagnetism.Now, most scholars still use the combination of traditional test and theoreticalcalculation as research methods for electromagnetic forming analysis. But this method istoo complicated, and many of the forming process transient variable cannot be fastidious.With the development of computer technology, as well as the finite element theory isbecoming more and more mature, scholars at home and abroad in recent years startedusing simulation studies in tube electromagnetic forming.Based on some reasonable simplifications, ANSYS was used for the finite elementsimulation of the electromagnetic tube-compression. The basic theory is provided for theelement numerical simulation of the tube，s deformation, by analyzing the finite elementmethod of electromagnetic tube-compression firstly. Scilicet, the boundary conditions andaxial symmetry of the electromagnetic field model were presented. The elastic-plastic FEM formulation was introduced, including yield criterion, hardening criterion andconstitutive equations etc. Based on the theory of finite element analysis ofelectromagnetic-structural coupled field, the mathematic model was created, and thephysical environment coupled physics analysis method was chosen to solve the coupledfield in the tube electromagnetic forming. In the process of tube electromagnetic forming,it is very difficult to carry out the simulation operation, for the change update of theelectric parameters and structure parameters of forming system. So, the numerical flowwas constructed with APDL in the software ANSYS, and the current density was appliedload.Secondly, after the finite element model is established, we had a load of theelectromagnetic tube-compression calculation and post-processing, simulated the tubedeformation and stress distribution of the whole process of forming. And on the basis ofthis system is mainly the change of process parameters on the influence of tube formingThrough a combination of single-factor and multi-factor analysis of variance variable,demonstrates the load frequency, the coil height, the size of the tube and coil spacing has asignificant impact on tube forming.Finally, conduct a simulation of tube forming with field shaper, through thecomparative analysis to reveal the influence of the field shaper in tube electromagneticforming. In addition, set a development analysis when the structure and material of thefield shaper changed. In a word, through the simulation analysis we found that the tubeelectromagnetic forming, its forming speed, tube stress is uniform, able to achieve goodforming effect. By the contrast of the tube deformation and stress distribution underdifferent parameters, can get the optimal value of the process parameters in theory. Forexample when the load current frequency is5.88KHZ the radial displacement of tube isthe largest in this paper. And the field shaper indeed can change the stress of tube and coil,the force distribution of the tube changes with the structure change of the field shaper.Moreover the use of field shaper can extend the life of the coil.