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A 2D finite element program, known as FAST_FORM2D, was developed at FTI to carry out section analysis in die design. Incremental method is employed and plane strain condition is assumed for 2D sections. Contact behavior and friction force are simulated by a developed algorithm. Therefore, the divergence problems related to the conventional contact techniques can be reduced or avoided. An adaptive mesh generation scheme is implemented to achieve computation efficiency. With the code, it is possible to evaluate tension, strain, thickness distributions and punch force at different stages for any 2D section cut from 3D panels. User can easily input or modify forming conditions to get the best solution.

The paper provides an overview of recent advances and applications of One Step FEM solvers in the automotive industry. The advances include, among other things, 1. Enhanced pre-processing (e.g. i. Integration with CAD Systems, ii. Automeshing), 2. Die processing geared functions (e.g. i. Automatic tipping, ii. Autoboundary conditions; to reduce effort in selecting the boundary conditions for achievement of a specific target strain in the panel), 3. More robust mechanics and realistic modeling of process (e.g. i. Autobending to accommodate membrane as well as bending and unbending effects, ii. Passive force formulation for a more realistic modeling of the external forces required to form the part, as well as iii. Curved binder capability; for more accurate prediction of binder effects), and 4. Enhanced post-processing and interpretation of results (e.g. i. Residual stresses, ii. Advanced FLD manipulation, iii.

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.