On a Fast Springback Program for Sheet Metal Stamping; Validation and Applications

A fast Springback capability was developed for up-front design of sheet metal stampings and related operations such as trimming. The intent, by analyzing formability and springback results, is to design a part and a robust process that will produce a World Class Quality. The FAST_SPRINGBACK program is based on a linear elastic Finite Element formulation with a degenerate 3-D shell element having 6/9 nodes. The starting point for the program is the forming strains that are available from FAST_FORM3D (a One Step FEM code) or alternatively other incremental forming software. A summary of validation results is outlined, ranging from analytical solutions for four basic membrane modes of deformation (balanced biaxial, plane strain, uniaxial tension and pure shear). Validation for pure bending mode is performed against experimental data obtained from a specially designed test rig. Validation based on standard benchmarks such as Numisheet 93 is also presented. Applications of the FAST_SPRINGBACK program at Styling, Product, Process and Tooling Designs are also presented.