Bending with upsetting of copper tube elbows

The purpose of this paper is to determine the basic parameters of copper elbow bending process: the value of the bending moment, the type and degree of deformation of cross-section and change of the wall-thickness for the bending process with and without participation of the axial upsetting force. The effect of axial upsetting force on the above mentioned parameters was determined. The results of calculation of the changes of outer wall-thickness were compared with the results of experimental measurement in the case of bending with and without upsetting when using both the simple and special mandrel.