Showing papers in "International Journal of Plasticity in 2008"

TL;DR: In this paper, the main ingredients and assumptions of developing macroscopic inelastic constitutive equations, mainly for metals and low strain cyclic conditions, have been discussed, with some comparisons with the previous ones, including more recent developments that offer potential new capabilities.

TL;DR: In this paper, a 3D asymmetric fracture locus, in the space of equivalent fracture strain, stress triaxiality and the Lode angle parameter, is proposed.

TL;DR: In this article, a single crystal constitutive law for multiple slip and twinning modes in single phase hcp materials is developed, where a dislocation population is evolved explicitly as a function of temperature and strain rate through thermally-activated recovery and debris formation and the associated hardening includes stage IV.

TL;DR: In this article, a combined fracture-plastic model for concrete is presented, which combines the fracture model and the crack band approach. And the model can be used to simulate concrete cracking, crushing under high confinement and crack closure due to crushing in other material directions.

TL;DR: In this article, the effect of stress triaxiality on the onset and evolution of damage in ductile metals is discussed and a series of tests including shear tests and experiments on smooth and pre-notched tension specimens was carried out for a wide range of stress-triaxialities.

TL;DR: In this article, Cazacu et al. proposed anisotropic yield functions for hexagonal close packed metals, which are extensions to the orthotropy of the isotropic yield function proposed in 2006, and showed that these yield functions represent with great accuracy both the tensile and compressive anisotropy in yield stresses and r -values of materials with hcp crystal structure and of metal sheets with cubic crystal structure.

TL;DR: In this article, an oligocrystal aluminum sample with a single quasi-2D layer of coarse grains is plastically deformed under uniaxial tensile loading and the history of strain localization, surface roughening, microstructure and in-grain fragmentation is carefully recorded.

TL;DR: In this article, the combined effects of void shape and matrix anisotropy on the macroscopic response of ductile porous solids are investigated, and the overall anisotropic yield criterion, a limit analysis approach is used.

TL;DR: In this paper, a material model for concrete is proposed within the framework of a thermodynamically consistent elasto-plasticity-damage theory, where two anisotropic damage tensors and two damage criteria are adopted to describe the distinctive degradation of the mechanical properties of concrete under tensile and compressive loadings.

TL;DR: In this paper, the Bauschinger effect, cyclic hardening/softening, strain range effect, nonproporitonal hardening, and strain ratcheting are discussed based upon representative experimental observations on several commonly used engineering materials.

TL;DR: In this article, a set of experiments was conducted on stainless steel (SS) 304L under various biaxial stress-controlled non-proportional histories and the results showed that loading nonproportionality on ratcheting responses of duplex stainless steel was a significant influence on the response of stainless steel.

TL;DR: In this article, a new phenomenological material model for shape memory alloys is proposed, which includes arbitrarily large deformations, and its efficient implementation into a finite element formulation is shown.

TL;DR: In this paper, a rate dependent, microstructure sensitive crystal plasticity model is formulated for correlating the mechanical behavior of a polycrystalline Ni-base superalloy IN 100 at 650°C.

TL;DR: In this paper, the phenomenological continuum plasticity models considering the unusual plastic behavior of magnesium alloy sheet were developed for a finite element analysis, and a hardening law based on two-surface model was further extended to consider the general stress-strain response of metal sheets including Bauschinger effect, transient behavior and unusual asymmetry.

TL;DR: In this paper, an experimental investigation of the Portevin-Le Chatelier (PLC) effect in the aluminium alloy AA5083-H116 is undertaken through five different tests involving round, prismatic and flat notched specimen geometries.

TL;DR: In this article, a generalized yield criterion, based on the parabolic Drucker and Prager criterion, is proposed including the first invariant of the stress tensor as well as the second invariant and the third invariant for the deviatoric part of the tensor.

TL;DR: In this article, the authors evaluated seven cyclic plasticity models for structural ratcheting response simulations, including bilinear, multilinear (Besseling), Chaboche, Ohno-Wang, Abdel Karim-Ohno and modified Ohnowang (Chen and Jiao).

TL;DR: In this article, numerical simulations and experimental results of nanoindentation on single crystal copper in three crystallographic orientations using a spherical indenter (3.4μm radius) were reported.

TL;DR: In this paper, a finite element formulation based on non-associated plasticity is developed in the constitutive formulation, isotropic hardening is assumed and an evolution equation for the hardening parameter consistent with the principle of plastic work equivalence is introduced.

TL;DR: Sun et al. as discussed by the authors extended the VBO model to account for crystallinity ratio on mechanical behavior of semicrystalline polymers, where amorphous and crystalline phase resistances acting in parallel were considered in the model, and the uniaxial loading and unloading behaviors can be simulated well with the modified VBO.

TL;DR: In this article, the grain size dependence of the flow strength of polycrystals is analyzed using plane strain, discrete dislocation plasticity, and constitutive rules are used to model lattice resistance to dislocation motion, as well as dislocation nucleation, dislocation annihilation and the interaction with obstacles.

TL;DR: In this article, molecular dynamics was employed to investigate dislocation nucleation from asymmetric (inclined) tilt grain boundaries under uniaxial tension applied perpendicular to the boundary.

TL;DR: In this paper, a new computationally efficient database approach to fully plastic Taylor-type crystal plasticity calculations is presented, which circumventes the need to repeatedly solve sets of highly non-linear, extremely stiff, algebraic equations with poor convergence characteristics that are inherent to these calculations.

TL;DR: In this paper, a modified Bodner-Partom model comprising hydrostatic and void evolution terms was proposed to describe the elasto-viscoplastic damage behavior of polymers.

TL;DR: In this paper, the authors investigated the capabilities of several non-quadratic polynomial yield functions to model the plastic anisotropy of orthotropic sheet metal (plane stress).

TL;DR: In this paper, the performance of different anisotropic yield functions in predicting the response and burst of tubes loaded under combined internal pressure and axial load was evaluated, and the results were used to calibrate the non-quadratic yield functions of Hosford and Karafillis-Boyce.

TL;DR: In this paper, a new three dimensional micromechanical model is proposed by coupling both the slip and twinning deformation mechanisms, which is implemented as User MATerial subroutine (UMAT) into ABAQUS/Standard.

TL;DR: In this paper, an elastic-plastic constitutive model including mixed isotropic-distortional hardening is presented, which is very simple and requires only experimental data that are part of the standard characterization of sheet metals.

TL;DR: In this article, the deformation of a Zr-based bulk-metallic glass in uniaxial, quasistatic, compression was investigated using an infrared camera.