Tendency of homogeneous radial deformation during electromagnetic compression of aluminium tube

Electromagnetic forming is one of the high-rate forming methods that can be extensively used to form and join axisymmetric metal sheet and tube. Tendency of homogeneous radial deformation during electromagnetic compression of aluminium tube was investigated through the design optimization method based on sequential coupling numerical simulation and experiments. The results show that the tendency depends on the length ratio of tube to coil (R), which has a critical value (R_c) corresponding to the relatively homogeneous radial deformation along axial direction. The tube length relative to R_c is insensitive to the discharge voltage. When R is greater than R_c, the deformed tube presents horn shape and the shorter coil makes for local deformation. If R is less than R_c, the deformed tube presents drum shape and the longer coil contributes to larger deformation at tube end. R_c increases with coli length and could approach to 1; inversely, it could approach to 0. These results indicate the design optimization method based on the sequential coupling numerical simulation is feasible, which can be used to realize the controllable and precise deformation of metal tube.