A Non‐Finite Element Friction Model for Tube Hydroforming Expansion into a 90‐degree Corner

A new non‐finite element friction model for tube hydroforming corner fill analysis has been introduced. The proposed model, which is applicable to 90‐degree die corners, is based upon geometric considerations and does not require an incremental solution scheme. Hoop strain distributions are evaluated using both FEA and the proposed theory. Overall correlation between the FEA and proposed solutions is quite respectable in light of the fact that the proposed friction model is based upon a non‐finite element theory which does not account for the intermediate deformation. This paper helps lay the groundwork for improvements in numerical modeling of friction effects on the hoop strain distribution in tubular hydroforming corner fill analysis when closed form solutions are required. The long term‐intent of this effort is to mold the proposed theory into a form that is accommodating to a more global contact model.