Research on Electromagnetic Force Distribution and Deformation Uniformity of Tube Electromagnetic Bulging Based on Concave Magnetic Field Shaper

Tube uneven radial deformation along the axial direction is one of the main technical problems of tube electromagnetic bulging, which restricts the wide advancement of this technology. In order to improve the uniformity of tube radial deformation, a tube electromagnetic bulging method based on concave magnetic field shaper is presented in this paper. Based on the theory of tube electromagnetic bulging and magnetic field shaper, an electromagnetic structure coupling finite element model is built using COMSOL commercial software. Obtained results show that the proposed concave magnetic field shaper can alter the magnetic field distribution on the tube to shape the produced electromagnetic force in a concave profile so that the tube can exhibit more uniform bulging effect. In the case study investigated in this paper, the maximum uniform region increases from 23.7mm to 56.2mm when the concave magnetic field shaper is used. Obviously, the introduction of concave magnetic field shaper can effectively solve the problem of the tube uneven radial deformation during electromagnetic bulging process, and promote more industrial applications of this technology.