Modeling slip, kink and shear banding in classical and generalized single crystal plasticity

Abstract Classical crystal plasticity can account for slip, kink and shear band formation in metal single crystals exhibiting a softening behavior. In the case of multiple slip, the stability of symmetric multi-slip configurations depending on the self/latent hardening ratio is investigated. Finite element simulations of symmetric and symmetry-breaking localization modes in single crystals oriented for double slip in tension are presented. Some shortcomings of classical crystal plasticity are then pointed out that can be solved using a Cosserat crystal plasticity model that explicitly takes elastoplastic lattice torsion-curvature into account. The classical theory predicts for instance the same critical hardening modulus for the onset of slip and kink banding. This is not the case any more in generalized crystal plasticity, as shown by a bifurcation analysis and finite element simulations of Cosserat crystals.

[1]  Jacques Besson,et al.  Large scale object-oriented finite element code design , 1997 .

[2]  J. Mandel Generalisation de la theorie de plasticite de W. T. Koiter , 1965 .

[3]  James R. Rice,et al.  Strain localization in ductile single crystals , 1977 .

[4]  Norman A. Fleck,et al.  The role of strain gradients in the grain size effect for polycrystals , 1996 .

[5]  R. D. Mindlin,et al.  On first strain-gradient theories in linear elasticity , 1968 .

[6]  B. Jaoul,et al.  Étude de la plasticité et application aux metaux , 1965 .

[7]  P. Franciosi,et al.  Latent hardening in copper and aluminium single crystals , 1980 .

[8]  Cristian Teodosiu,et al.  Elastic Models of Crystal Defects , 1982 .

[9]  J. Mandel,et al.  Equations constitutives et directeurs dans les milieux plastiques et viscoplastiques , 1973 .

[10]  A. Seeger,et al.  Untersuchung des Gleitlinienbildes Kubisch-flächenzentrierter einkristalle , 1960 .

[11]  Y. Estrin,et al.  Local strain hardening and nonuniformity of plastic deformation , 1986 .

[12]  S. Mader Elektronenmikroskopische Untersuchung der Gleitlinienbildung auf Kupfereinkristallen , 1957 .

[13]  Georges Cailletaud,et al.  A Cosserat theory for elastoviscoplastic single crystals at finite deformation , 1997 .

[14]  J. Garstone,et al.  Easy glide of cubic metal crystals , 1956 .

[15]  E. Kröner,et al.  On the physical reality of torque stresses in continuum mechanics , 1963 .

[16]  J. Nye Some geometrical relations in dislocated crystals , 1953 .

[17]  P. Germain,et al.  The Method of Virtual Power in Continuum Mechanics. Part 2: Microstructure , 1973 .

[18]  J. Y. Shu Bicrystals with strain gradient effects , 1996 .