Research on equivalent model of forming test for stator coils of permanent magnet traction motors

In response to the requirements for equivalent testing of the expansion of stator coils in permanent magnet traction motors, an alternative method for calculating the dimensions and loading conditions of equivalent specimens is proposed. Numerical simulation analysis is conducted on the bending forming process of both the stator coil and the equivalent specimen. Based on the Ramberg-Osgood model, an elastic-plastic equivalent strain ratio coefficient (λ) is introduced to describe the proportion of forming elastoplasticity to the total strain. The results indicate that the mean deviation of λ for the two corresponding forming methods is 2.03%, with a maximum deviation not exceeding 8.05%. By comparing the springback values of the actual produced stator coils with the numerical simulation results of the equivalent specimens, the feasibility of the elastoplastic theory and the validity of the equivalent model are verified.