An Anisotropic Elastic-plastic Model for the Optimization of a Press Machine’s Auxiliary Worktable Plate Thickness

W. Rajhi, B. Ayadi, A. Alghamdi, N. Messaoudene


In this work an anisotropic elastic–plastic finite element model strongly coupled with ductile damage is applied to determine the suitable thickness of added auxiliary worktable plate to a 100 ton maximum capacity press machine. The major focus of this study is to minimize the amount of stress transmitted to the optional worktable plate and the press machine body while allowing them to withstand plastic deformation and damage during compression testing until final sample fracture. The worktable plates and the press machine body are made of TRIP800 grade steel. AISI 316L stainless steel is chosen as test material for the cylindrical billets. The proposed model is based on a non-associative plasticity theory and the “Hill 1948” quadratic (equivalent) stress norm is considered to describe the large plastic anisotropic flow accounting for mixed isotropic and kinematic hardening with isotropic damage effect. For each material the model uses an experimental data base obtained from a set of tensile tests conducted until the final fracture in three directions, the rolling direction (RD) or 0, the transverse direction (TD) or 90, and the 45 direction. After several numerical simulations of compression testing using ABAQUS/Explicit FE® software, thanks to the user’s developed VUMAT subroutine, varying cylindrical billet diameters and material, worktable plates number and thicknesses and spatial plate configurations the solution of 100mm thick worktable plate is selected since in that case the cylinder specimen is totally damaged and the stress state inside the worktable plates and the press machine body remains admissible.


compression testing; hardening; plastic anisotropy; ductile damage; iIdentification; numerical simulation

Full Text:



K. Saanouni, J. F. Mariage, A. Cherouat, P. Lestriez, “Numerical prediction of discontinuous central bursting in axisymmetric forward extrusion by continuum damage mechanics”, Computers & structures, Vol. 82, No. 27, pp. 2309-2332, 2004

M. Khelifa, H. Badreddine, A. Daoud, M. A. Gahbich, K. Saanouni, A. Cherouat, A. Dogui, “Effect of anisotropic plastic flow on the ductile damage evolution in hydrobulging test of thin sheet metal”, International Journal of Forming Processes,Vol. 8, No. 2, pp. 271-289, 2005

H. Badreddine, C. Labergere, K. Saanouni, W. Rajhi, A. Rassineux, D. Kircher, “FE elastoplastic damage model with 2D adaptive remeshing procedure for fracture prediction in metal forming simulation”, International Journal of Material Forming, Vol. 1, pp. 109-112, 2008

C. Labergère, K. Saanouni, P. Lestriez, “Numerical design of extrusion process using finite thermo-elastoviscoplasticity with damage. Prediction of chevron shaped cracks”, Key Engineering Materials, Vol. 424, pp. 265-272, 2010

K. Saanouni, Damage Mechanics in Metal Forming: Advanced Modeling and Numerical Simulation,Wiley, 2012

M. Issa, K. Saanouni, C. Labergere, “Prediction of serrated chip formation in orthogonal metal cutting by advanced adaptive 2D numerical methodology”, International Journal of Machining and Machinability of Materials, Vol. 9, No. 3, pp. 295–315, 2011

K. Saanouni, N. Belamri, P. Autesserre, “3D numerical simulation of anisotropic thin sheet metal slitting process using fully coupled constitutive equations including ductile damage”, International Journal of Material Forming, Vol. 2, No. 1, pp. 535-538, 2009

C. Labergère, A. A. Rassineux, K. Saanouni, “2D adaptive mesh methodology for the simulation of metal forming processes with damage”, International Journal of Material Forming, Vol. 4, No. 3, pp. 317-328, 2011

W. Rajhi, K. Saanouni, H. Sidhom, “Anisotropic ductile damage fully coupled with anisotropic plastic flow: Modeling, experimental validation, and application to metal forming simulation”, International Journal of Damage Mechanics, Vol. 23, No. 8, pp. 1211-1256, 2014

K. Saanouni, J. L. Chaboche, “Computational damage mechanics: Application to metal forming simulation”, Comprehensive Structural Integrity.Vol. 3, pp. 321–376, 2003

H. Badreddine, K. Saanouni, A. Dogui, “On non-associative anisotropic finite plasticity fully coupled with isotropic ductile damage for metal forming”, International Journal of Plasticity, Vol. 26, No. 11, pp. 1541-1575, 2010

H. Badreddine, K. Saanouni, T. D. Nguyen, “Damage anisotropy and its effect on the plastic anisotropy evolution under finite strains”, International Journal of Solids and Structures, Vol. 63, pp. 11-31, 2015

K. Saanouni, A. Cherouat, Y. Hammi, “Numerical aspects of finite elastoplasticity with isotropic ductile damage for metal forming”, Revue Européenne des Elements Finis, Vol. 10, No. 2-4, pp. 327-351, 2001

C. L. Chow, T. J. Lu, “A normative representation of stress and strain for continuum damage mechanics”, Theoretical and Applied Fracture Mechanics, Vol. 12, pp.161–187, 1989

C. L. Chow, J. Wang, “An anisotropic theory of continuum damage mechanics for ductile fracture”, Engineering Fracture Mechanics, Vol. 27, pp. 547- 558, 1987

C. L. Chow, J. Wang, “Ductile fracture characterization with an anisotropic continuum damage theory”, Engineering Fracture Mechanics Vol. 30, pp. 547–563, 1988

J. Lemaitre, R. Desmorat, M. Sauzaya, “Anisotropic damage law of evolution”, European Journal of Mechanics, Vol. 19, pp. 187–208, 2000

K. Saanouni, M. Hamed, “Micromorphic approach of finite gradient-elastoplasticity fully coupled with ductile damage: Formulation and computational approaches”, International Journal of Solids and Structures, Vol. 50, pp. 2289–2309, 2013

eISSN: 1792-8036     pISSN: 2241-4487