Effect of forming and calibration operations on the final shape of large diameter welded tubes

The aim of this search is to investigate stress and strain state in the tube; in particular the action of the expanding machine is simulated and the effect on the tube section end profiles and on the tube lengthwise inflection have been evaluated. The possibility of both obtaining a good circular shape of the tube section and correcting the lengthwise inflection is investigated. The FE model is defined according to data coming from the workshop: the sheet material is X70 steel and initial blank dimensions are 14,000 mm × 3000 mm × 27.5 mm.