Numerical analysis of an inside-out tube inversion process

There has been much research on the tube inversion process. However, the effect of anisotropy on the process is less reported. In this paper, a numerical method based on the Hill's plastic anisotropic theory and the membrane theory of shells has been proposed to analyse the tube inversion process with consideration of anisotropy. In the present method, a system of first-order ordinary differential equations have been developed. By solving these equations, the deformation behaviour of the tube and the effect of the anisotropy on the process can be obtained. The predicted loads were found to be in good agreement with experimental results and the plastic anisotropy of the sheet has been shown to have a significant effect on the process. This simple numerical method is demonstrated to be practical, accurate and appropriate for the analysis of other axisymmetric tube-forming process.