Showing papers in "International Journal of Plasticity in 1995"

TL;DR: In this paper, a modification of the dynamic recovery term of the AF rule is considered as recently proposed by Ohno and Wang [1991a,1991b], which is established based on certain assumed crystalline slip system behavior and interaction between dislocation interactions at different size scales.

TL;DR: In this paper, the effects of varying triaxiality and strain rate on the critical void volume fraction were investigated under different constitutive models for the matrix material, i.e., rate independent plastic material with isotropic hardening, visco-plastic material under both isothermal and adiabatic conditions, and porous plastic materials with a second population of voids nucleating strain controlled.

TL;DR: In this paper, a set of experimental basis of unidirectional and bidirectional ratchet was created for the quantitative description of the ratchet phenomena, and it was shown that the rate of diametral ratchet is an increasing function of the phase angle between the cyclic components.

TL;DR: In this paper, a hybrid finite element formulation for the plastic deformation of FCC metals with anisotropic anisotropy is outlined, where polycrystal plasticity theory is used to develop the constitutive response and the hybrid approach facilitates introduction of the microscale stress in the macroscopic statement of equilibrium.

TL;DR: In this paper, finite element analysis is used to numerically study necking and neck propagation in amorphous glassy polymers under plane strain tension during large strain plastic flow.

TL;DR: In this article, a general framework for the development of plastic or viscoplastic constitutive equations is described, which is restricted to the case of quadratic criteria, and specially to the study of various interactions which can be introduced between the mechanisms.

TL;DR: In this article, a constitutive analysis for inelastic stress and strain rates is presented, and the energy dissipation rate and the thermodynamic forces conjugate to elastic stiffness and compliance tensors are identified, based on a thermodynamic analysis of isothermal deformation process.

TL;DR: In this article, an elastoplastic self-consistent model has been implemented to perform a systematic study of the response of rolled Zircaloy-2 subjected to mechanical loading.

TL;DR: In this paper, a comparative study between a nonlinear kinematic hardening model and a generalized plasticity model is presented from both continuous and discrete time points of view, and the integration of the discrete models based on a return map algorithm is also addressed.

TL;DR: In this article, the validity of the principle of superposition for incremental loading in incrementally piece-wise linear constitutive relations is evaluated using a numerical testing procedure, and it is shown that this principle is valid only inside the linearity domains of the constitutive relation.

TL;DR: In this article, Rohde et al. studied the problem of twinning in polymeric materials and found that the predictions of the theory are remarkably close to the experimental results of Madhava et al., both qualitatively and quantitatively.

TL;DR: In this article, a static approach for quasistatic (elastic) shakedown of elastoplastic solids with nonassociative plastic flow rules or nonlinear hardening is proposed.

TL;DR: In this article, the macroscopic behavior of single-crystal superalloys under torsion or tension-torsion loadings was investigated at room temperature, on tubular specimens equipped with micro strain-gages for local deformation measurements.

TL;DR: In this paper, a non-linear instability condition for the viscoplastic strain softening model during the creep process is obtained and the preferred orientation for the growth of fluctuation and the instability condition are derived.

TL;DR: In this article, a general anisotropic yield surface using a fourth order Mijkl tensor has been proposed, based on the physical behavior observed for the material under consideration, which can be used for either pressure dependent or independent cases.

TL;DR: In this paper, an experimental technique for the evaluation of the in-plane yield loci of sheet metals with the cruciform plate specimen is presented, which conforms to the optimized design concept proposed by other researchers.

TL;DR: In this article, a generalized formulation of the nonhardening region is proposed, which assumes that an isotropic hardening does not proceed when a plastic strain exists inside a hypersphere in the plastic strain space.

TL;DR: In this paper, an experimental and numerical study of the uniaxial cyclic behaviour of the aluminium alloy AA6060 in tempers T4 and T6 is reported, where material characteristics studied through the experimental programme are the monotonic stress-strain curve, the shape of the hysteresis loops, cyclic hardening and softening, mean stress relaxation and memorization of prior strain histories.

TL;DR: In this paper, the authors model cyclic hardening, cyclic softening and cyclic mean stress relaxation in elastic-plastic loading in a continuous manner, by means of hardening functionals for back stress and yield stress without employing additional memory surfaces.

TL;DR: In this article, a time-independent plasticity model using only one yield surface and capable of predicting cyclic loading is presented, where memory points are defined to monitor the loading history; these memory points have the property that they can be created and disappear during the load history.

TL;DR: In this article, an energy-based theory of localization is developed through the analysis of dynamic simple shearing motion of a thermo-viscoplastic solid, where the total kinetic energy serves as a single parameter for the characterization of the full localization history.

TL;DR: In this article, the ductile damage of materials is introduced into the shakedown theory of strain-hardening structures, and a mathematical programming method is developed to calculate an upper bound of the damage factor in a structure subjected to varying loads, which is suggested as the criterion of structural failure.

TL;DR: In this paper, an anisotropic quadratic form of plastic strain increment is used to define the intrinsic time in the endochronic theory of plasticity and a yield function can be derived based on this new definition.

TL;DR: In this article, the influence of three primary dimensionless groups on localizing sensitivity is examined. And the limits of applicability of the quasistatic assumption as well as the adiabatic deformation assumption are also addressed.

TL;DR: In this article, the authors investigated the relationship between the plastic spin and the noncoaxiality between the stress and the plastic rate of deformation in simple shear bands.

TL;DR: In this paper, a micromechanically based continuum model is developed to analyze the enhancement of plastic properties of particulate-reinforced metal-matrix composites over matrix materials.

TL;DR: In this article, a recently developed damage-plasticity model for metal matrix composites is examined using the overall approach to damage, where the damage mechanisms in the composite system are reflected through a single overall damage tensor assuming an elastoplastic matrix with elastic fibers.

TL;DR: In this article, the effects of void clustering on ductile fracture were studied by modeling a discrete set of randomly distributed clusters, each cluster consists of four equally-spaced, cylindrical voids.

TL;DR: In this article, the incremental endochronic plasticity of metals is extended into a finite element analysis (called EndoFEM), and the computational results are very unique under various step sizes of load increment and various values of convergent tolerance.

TL;DR: In this article, small strain constitutive equations are developed for the thermomechanical behavior of semiconductor single crystals, including dislocation density as an evolving parameter, and the model of Haasen, Alexander and coworkers is modified (extended) to include evolution of coefficients in the definition of internal stress.