Robotic SPIF Numerical Chain Development and Validation

This work focuses on the robotic incremental forming process. The general objective of this study is to provide an instrumented device dedicated to the qualifying of the forming of typical cases. The manufacturing cell is equipped to evaluate in situ the characteristics of the process as a function of: (i) the tool diameter; (ii) the feed rate; (iii) the rotational speed i and (iv) the step size. In a first approach, the influence of these operating parameters on the quality of the part is studied by forming spherical shapes. The material is an AA5754-H11 aluminum sheet whose behavior is characterized by tensile tests at room temperature. The robot movements are analyzed by laser scanning to highlight the dispersions induced by the joint stiffness and the deformations of its structure. The observed deviations will be used in future work to improve the control of the robot trajectories. The tool/material interaction and the behavior of the shaped sheet are studied by image analysis based on the experimental results. A preliminary numerical model of the process is proposed, to analyze the evolution of the forming forces and the equivalent plastic strain. The predictions correlate well with experiments and several future development paths are derived from the comparison.