Comparison between Experimental and Numerical Results of Electromagnetic Tube Expansion

Electromagnetic forming is a complex coupled mechanical-thermal-electromagnetic phenomenon. To accurately simulate this high-velocity and high-strain-rate process, electromagnetism (EM) module of LS-DYNA has been developed. In this paper, the predictive ability of the EM module is assessed through a comparison between experimental and numerical results of electromagnetic tube expansion. The experiment was to apply electromagnetic forming for expansion of Al 6061-T6 tube. Photon Doppler Velocimetry (PDV) was used to measure the velocity during the tube expansion. This process was also modeled using LS-DYNA EM module. Different parameters of Johnson-Cook strength model for Al 6061-T6 were applied to verify the constitutive model parameters for Al 6061-T6. Moreover, 2D axi-symmetric simulations with different mesh densities were performed in this case. A comparison of the expansion velocity between experimental and numerical results is presented and discussed. The good agreement was found between the experimental and numerical results.