Forming forces in single point incremental forming: prediction by finite element simulations, validation and sensitivity

The aim of this article is to study the accuracy of finite element simulations in predicting the tool force occurring during the single point incremental forming (SPIF) process. The forming of two cones in soft aluminum was studied with two finite element (FE) codes and several constitutive laws (an elastic–plastic law coupled with various hardening models). The parameters of these laws were identified using several combinations of a tensile test, shear tests, and an inverse modeling approach taking into account a test similar to the incremental forming process. Comparisons between measured and predicted force values are performed. This article shows that three factors have an influence on force prediction: the type of finite element, the constitutive law and the identification procedure for the material parameters. In addition, it confirms that a detailed description of the behavior occurring across the thickness of the metal sheet is crucial for an accurate force prediction by FE simulations, even though a simple analytical formula could provide an otherwise acceptable answer.

[1]  John E. Dennis,et al.  Numerical methods for unconstrained optimization and nonlinear equations , 1983, Prentice Hall series in computational mathematics.

[2]  Serge Cescotto,et al.  Calibration and application of an elastic viscoplastic constitutive equation for steels in hot‐rolling conditions , 1985 .

[3]  François Frey,et al.  Nonlinear thin shell finite element with six degrees of freedom per node , 1989 .

[4]  J. Lemaitre,et al.  Mécanique des matériaux solides , 1996 .

[5]  Serge Cescotto,et al.  Contact between deformable solids: The fully coupled approach , 1998 .

[6]  U. F. Kocks,et al.  Physics and phenomenology of strain hardening: the FCC case , 2003 .

[7]  Dong-Yol Yang,et al.  Development of a Highly Flexible Incremental Roll Forming Process for the Manufacture of a Doubly Curved Sheet Metal , 2003 .

[8]  Robert H. Wagoner,et al.  A New Hexahedral Solid Element for 3D FEM Simulation of Sheet Metal Forming , 2004 .

[9]  Christophe Henrard,et al.  Finite Element Modeling of Incremental Forming of Aluminum Sheets , 2005 .

[10]  J. Jeswiet,et al.  Forces in Single Point and Two Point Incremental Forming , 2005 .

[11]  Bert Lauwers,et al.  Achievable accuracy in single point incremental forming: case studies , 2005 .

[12]  Joost Duflou,et al.  Asymmetric single point incremental forming of sheet metal , 2005 .

[13]  Paul Vanherck,et al.  Force Measurements for Single Point Incremental Forming: An Experimental Study , 2005 .

[14]  Christophe Henrard,et al.  Development of a contact model adapted to incremental forming , 2005 .

[15]  Joost Duflou,et al.  Some considerations on force trends in Incremental Forming of different materials , 2007 .

[16]  Joost Duflou,et al.  Model Identification and FE Simulations Effect of Different Yield Loci and Hardening Laws in Sheet Forming , 2007 .

[17]  Joost Duflou,et al.  Forming Limit Predictions for the Serrated Strain Paths in Single Point Incremental Sheet Forming , 2007 .

[18]  A. Erman Tekkaya,et al.  The Increased Forming Limits of Incremental Sheet Forming Processes , 2007 .

[19]  Jun Gu,et al.  Development of an inverse method for identification of materials parameters in the single point incremental sheet forming process , 2007 .

[20]  Joost Duflou,et al.  Force Analysis for Single Point Incremental Forming , 2007 .

[21]  Laurent Duchene,et al.  Length changes and texture prediction during free end torsion test of copper bars with FEM and remeshing techniques , 2007 .

[22]  Wilko C. Emmens,et al.  Strain in Shear, and Material Behaviour in Incremental Forming , 2007 .

[23]  P. Houtte,et al.  An extended Marciniak-Kuczynski forming limit model to assess the influence of through-thickness shear on formability , 2008 .

[24]  Paulo A.F. Martins,et al.  Revisiting the fundamentals of single point incremental forming by means of membrane analysis , 2008 .

[25]  Joost R. Duflou,et al.  Process window enhancement for single point incremental forming through multi-step toolpaths , 2008 .

[26]  Christophe Henrard,et al.  Comparison of the tests chosen for material parameter identification to predict single point incremental forming forces , 2008 .

[27]  Joost Duflou,et al.  Identification of material parameters to predict Single Point Incremental Forming forces , 2008 .

[28]  Joost Duflou,et al.  Small-scale Finite Element Modelling of the Plastic Deformation Zone in the Incremental Forming Process , 2008 .

[29]  A. H. van den Boogaard,et al.  An overview of stabilizing deformation mechanisms in incremental sheet forming , 2009 .

[30]  Philip Eyckens,et al.  Marciniak–Kuczynski type modelling of the effect of Through-Thickness Shear on the forming limits of sheet metal , 2009 .

[31]  Julian M. Allwood,et al.  Generalised forming limit diagrams showing increased forming limits with non-planar stress states , 2009 .

[32]  S. Bouvier,et al.  Numerical simulation of sheet metal forming using anisotropic strain-rate potentials , 2009 .

[33]  Joost R. Duflou,et al.  Force prediction for single point incremental forming deduced from experimental and FEM observations , 2010 .

[34]  Jun Gu,et al.  Strain evolution in the single point incremental forming process: digital image correlation measurement and finite element prediction , 2011 .