Springback Modification for Biaxial Bending Plate and Its Validation in Multipoint Forming An new algorithm of springback modification is proposed for biaxial bending plate with variable curvature. By the algorithm, the precision forming for Multipoint die can be realized. The idea of discretization is introduced into the algorithm, the whole sheet metal surface was divided into microplate elements. The curvature formulas of microplate elements were given after springback modification. Based on curvature information of the discrete microplate elements, a series of characteristic points obtained by interpolation. Then, The theory of Bezier surface joining is applied to reconstruct the whole bending surface after springback modification. Due to the die surface of multipoint forming is reconfigurable, discrete elements in upper and lower multipoint dies are adjusted to reconstructed surface after modification. According to the compensated and modified shapes, finite element models for multipoint forming are established and analyzed. Experiments have also been completed with multipoint dies. And the results of simulation and experiment are compared with desired shapes, the contrast results show that the springback modification algorithm can effectively controlling forming precision for biaxial bending plate with variable curvature.

Improvement of DataDriven 3D Surface Quality Inspection by Deformation Simulation The automated visual inspection of complexly shaped, stamped sheet metal is a challenging task. Modelbased methods are currently state of the art for surface quality inspection based on threedimensional surface measurements. Datadriven models allow the representation of arbitrary threedimensional surface shapes including possible tolerances and variation due to deformation. Providing a sufficient amount of training data while ensuring adequate data quality is a timeconsuming and laborous process. We propose a data driven threedimensional surface model for quality inspection that allows the integration of deformation simulation in order to increase variance in training data. The effects of simulated data to the model quality are evaluated and results are given for data sets of automobile sheet metal parts.