A study of 3D finite element modeling method for stagger spinning of thin-walled tube

A modified 3D finite element (3D-FE) model is developed under the FE software environment of LS-DYNA based on characteristics of stagger spinning process and actual production conditions. Several important characteristics of the model are proposed, including full model, hexahedral element, speed boundary mode, full simulation, double-precision mode, and no-interference. Modeling procedures and key technologies are compared and summarized: speed mode is superior to displacement mode in simulation accuracy and stability; time truncation is an undesirable option for analysis of the distribution trend of time-history parameters to guarantee that the data has reached the stable state; double-precision mode is more suitable for stagger spinning simulation, as truncation error has obvious effects on the accuracy of results; interference phenomenon can lead to obvious oscillation and mutation simulation results and influence the reliability of simulation significantly. Then, based on the modified model, some improvements of current reported results of roller intervals have been made, which lead to higher accuracy and reliability in the simulation.