Three-Dimensional Bending of Profiles by Stress Superposition

The paper shows a number of investigation results about three- dimensional-bending of profiles. The investigations concentrated on two-dimensional bending using a conventional three-roll-bending machine with a simultaneous deflection of the profiles towards the third axis by means of a special device. The special device consists of a hydraulic cylinder giving the motion and the required force for bending in the third axis coupled with a guiding tool to guide the profile in the 3D-space. The most important aspect of these tools is the use of the previous plastic deformation in the 2D-bending zone for an easier bending in the 3D-space through the superposition of lateral forces. By means of this machine set-up both symmetrical and asymmetrical profiles can be bent three-dimensionally and the unwanted torsion of asymmetrical profiles can be prevented through a compensation moment.