Shell element simulation of the push method of tube bending

Purpose: In this paper the new push bending process for the forming of curved tubes is simulated using the finite element method. It is demonstrated that the results obtained using shell elements compare closely with those obtained earlier using three-dimensional elements. A parametric study is carried out which gives on indication of the effect of changes in geometry and material properties on results. Design/methodology/approach: A non-linear finite element analysis is carried out using the program LS-DYNA. A bilinear elastic plastic material is assumed, and both aluminum and steel are modelled. Findings: It is found that the radius of the bend is significant with respect to potential wrinkling. The inner pressure can be increased to suppress possible wrinkling. Lubrication is shown to be significant with regard to final results for wall thickness. Research limitations/implications: The present work is restricted to quasi-static behavior, and thermal effects are not considered. Practical implications: Some limitation on thickness variation in the finished product is possible through choice of lubricant. Originality/value: This paper gives original simulated results for tube push bending relating to new geometries and different materials.