Deformation Analysis And Discharge Energy Forecast Of Tube Electromagnetic Forming

In the process of tube electromagnetic forming (EMF), it is very difficult to study the law of deformation of tubes under pulse magnetic force, for the real-time interaction between the electric parameters and the structure parameters of forming system. In addition, the relationship between discharge energy and the deformation of workpiece cannot easily be figured by analytic method, which is also a big obstruction to the development of EMF. In this thesis, the deformation of electromagnetic tube-compression and bulging were investigated by numerical simulation and experiment. Some main forming parameters that could effect the radial displacement of tube were analyzed. Based on numerical simulation of electromagnetic-structural coupled field and the optimization design method, the discharge energy forecast of EMF system was also investigated.Based on the theory of finite element analysis (FEA) of electromagnetic-structural coupled field, the mathematic model, the boundary conditions and axial symmetry of the electromagnetic field model and the elastic-plastic FE theory of structure field were presented. And the loosely coupled physics analysis method was chosen to solve the coupled field in the tube electromagnetic forming.Using the multi-physics environment FEM software ANSYS, the numerical simulation flow of the loosely coupled electromagnetic-structural field were constructed. The deformation process of tube in tube-compression and bulging was investigated by both numerical simulation and experiment. The results show that the radial displacement of tube electromagnetic forming is non-uniform along the axial direction and increases with the discharge voltage. For tube-compression, keeping the discharge energy and the tube length constant, the shorter coil is propitious to local deformation; with the increase of tube length, the radial displacement decreases, the length of forming region augments and the deformation in the middle of the tube tends to be uniform. For tube electromagnetic bulging, with constant discharge energy, there is an optimum discharge frequency for the radial deformation, which is about 4 kHz in this thesis. Under the same discharge voltage, the radial displacement of the bulged...