Numerical Analysis of Tube Expansion by Electromagnetic Forming Using Magnetic Field Shaper

Uneven axial deformation is the current main issue of the tubes electromagnetic bulging technology which calls for innovative and cost-effective solutions. This paper presents a new method to overcome the above-mentioned issue based on employing a magnetic field shaper. The proposed magnetic field shaper is employed in the middle of the pipe and the driving coil. Induced eddy current control is realized by changing the structural parameters of the magnetic field shaper; thereby regulating the electromagnetic force distribution. The effectiveness of the proposed method is investigated through numerically comparing the electromagnetic performance of two EMF setups; traditional coil-based loading model and magnetic field shaper driving coil-based loading model proposed in this paper. The influence of the magnetic field shaper structural parameters on the tube electromagnetic forming performance is examined for optimum structure design. Results reveal that the concave profile of the radial electromagnetic force in the traditional loading method can be effectively improved using the proposed loading in this paper. The introduction of a magnetic field shaper not only changes the induced eddy current distribution, but also regulates the electromagnetic force profile in the axial-direction of the pipe which effectively enhances the uniform range of the pipe electromagnetic bulging, the maximum uniform deformation area is increased from 9mm to 35mm.