Original Articles: 2014 Vol: 6 Issue: 3
Research on the new load patterns for multi-roller stretch forming process
Multi-roller stretch forming process (MRSF) is a flexible manufacturing technique to form sheet panels into different curvature. Based on the geometrical relationship of 3D surface stretch forming by MRSF, an inscribed arc of the roller’s critical position has been established by adopting geometric analytical method. With the arc, the variation regulation of loading force on each roller is obtained using the principle that the stretch force on each roller stays the same in all places. Numerical simulations have been done for forming the 08Al spherical parts by MRSF with the equal force and variable force loading methods respectively. The results show that the flexibility, die fittingness, strain and stress distribution as well as the quality of variable force loading by MRSF are the best among these types, equal force loading method is a little worse than the former, however the traditional stretch forming process with rigid-clamps (RCSF) is not flexible and it is hard to make the blank and die jointed. In addition, the phenomenon of stress concentration is serious and the quality of the formed parts is the worst.