Modeling of the metal powder compaction process using the cap model. Part II: Numerical implementation and practical applications

Abstract The finite element (FE) simulation method has recently been used as an alternative design tool in powder metallurgy (PM) industry. It allows for the prediction of density and stress distributions in the pressed compact prior to the actual tooling design and manufacturing activity. It thus makes possible the validation of the PM part and associated tooling design. However, the accuracy of FE prediction highly depends on the choice of an appropriate and well calibrated powder material model, as well as on the effectiveness of the computational environment. While the first point was presented in a previous work, the present paper addresses some computational aspects of compaction process modeling approach in the context of industrial production environment. Hence, this paper presents a discussion of the choice of stress and strain measures used in this large deformation context. It also presents the implementation of the cap constitutive model into abaqus FE software using the closest point projection algorithm. Furthermore, an integrated simulation module has been developed and is described herein. This module, designed in order to render the modeling approach practical and industrially attractive to PM engineers, permits an easy definition of the tooling and the powder geometry, as well as the prescription of compaction sequence and all other boundary conditions. Finally, the simulation of the compaction of an industrial PM part, intended to illustrate the usefulness of the simulation approach in the task of improving the design of PM part and process, is presented.

[1]  J. C. Simo,et al.  Algorithms for static and dynamic multiplicative plasticity that preserve the classical return mapping schemes of the infinitesimal theory , 1992 .

[2]  J. C. Simo,et al.  A modified cap model: Closest point solution algorithms , 1993 .

[3]  F. Lenel,et al.  Powder Metallurgy: Principles and Applications , 1980 .

[4]  I. S. Sandler,et al.  An algorithm and a modular subroutine for the CAP model , 1979 .

[5]  E. Kröner,et al.  Allgemeine Kontinuumstheorie der Versetzungen und Eigenspannungen , 1959 .

[6]  F. Dimaggio,et al.  MATERIAL MODEL FOR GRANULAR SOILS , 1971 .

[7]  J. Mandel,et al.  Plasticité classique et viscoplasticité , 1972 .

[8]  E. H. Lee,et al.  Finite‐Strain Elastic—Plastic Theory with Application to Plane‐Wave Analysis , 1967 .

[9]  D. Owen,et al.  A model for finite strain elasto-plasticity based on logarithmic strains: computational issues , 1992 .

[10]  Karl S. Pister,et al.  Assessment of cap model: consistent return algorithms and rate-dependent extension , 1988 .

[11]  R. German Powder metallurgy science , 1984 .

[12]  Augustin Gakwaya,et al.  Modeling of the metal powder compaction process using the cap model. Part I. Experimental material characterization and validation , 2002 .

[13]  J. Marsden,et al.  Product formulas and numerical algorithms , 1978 .

[14]  Michael Ortiz,et al.  A unified approach to finite deformation elastoplastic analysis based on the use of hyperelastic constitutive equations , 1985 .

[15]  J. C. Simo,et al.  Non‐smooth multisurface plasticity and viscoplasticity. Loading/unloading conditions and numerical algorithms , 1988 .

[16]  G. Dhatt,et al.  Une présentation de la méthode des éléments finis , 1984 .