Strategi og modell for halvautomatisk styring av plateformingsmaskin

This report develops a methodology for the determination of bending parameters in an incremental bending jig for shaping aluminum panels for use in boat hulls. The panels are extruded and friction welded profile-based aluminum sheets with integrated T-stiffeners in alloy AA6082-T4. The main work includes development of a FEM-model for incremental multi-step forming, with springback-calculations in the metal forming software “Stampack”. Results from practical experiments form the basis for comparison for the model. A manual and an automated procedure for the description of hull geometries in the CAD software “Rhinoceros” have been developed. Furthermore, a simple method that uses CAD software to determine the bending parameters for single curved geometries have been developed. The FEM-model provides a good match with practical experiments for single-profile (beam) geometries, with an average springback-deviation of 10 %. For the forming of profile-based sheets, there is a significant deviation of 20 – 45 %. Automated description of hull geometries in “Rhinoceros” works satisfactorily when using simple, single-curved geometries. The sequential forming strategy has been tested using single-curved geometries produced with the FEM-model. The results show that the model estimates approximately 27 % lower punch displacements than necessary. The deviation seems to be constant, so that an accurate geometry is achieved by increasing the displacements with 27 %.