Most of the observational claims in cosmology are based on the assumption that the universe is isotropic and homogeneous so they essentially test different types of Friedmann models. This also refers to recent observations of supernovae Ia, which, within the framework of Friedmann cosmologies give strong support to negative pressure matter and also weaken the age conflict. In this essay we drop...

Abstract An holistic view is attempted towards prediction of the effect residual stresses induced by full-forward extrusion on fatigue life workpieces during operation. To study constitutive model accuracy forming simulations, a combined nonlinear isotropic/kinematic hardening as well isotropic part same are calibrated based five compression-tension-compression uniaxial stress experiments. A fi...

Advanced hardening models accurately describe the transient plastic behavior (reyielding, stagnation, resumption...) after various strain-path changes (reverse, orthogonal...). However, a common drawback of these is that they usually predict monotonic loading with lower accuracy than regular isotropic models. Consequently, finite element predictions using may sometimes lose in accuracy, spite t...

The influence on macroscopic work hardening of small, spherical, elastic particles dispersed within a matrix is studied using an isotropic strain gradient plasticity framework. An analytical solution for hardening, i.e. the flow stress as function plastic strain, based recently developed model initial yield strength proposed. accounts random variations in particle size and properties, numerical...

An 8-node quadrilateral plane element US-QUAD8 is developed for linear isotropic hardening material in the framework of updated Lagrangian unsymmetric finite formulation where B L matrix constructed by classical shape function, and R higher-order basis function global coordinate system. The present eliminates influence Jacobian elemental stiffness guarantees quadratic completeness displacement ...

K 〈x, y〉 dy = ‖x‖ By ‖·‖ we denote the standard Euclidean norm. The notion of isotropic position was extensively studied by V. Milman and A. Pajor [M-P]. Note that our definition is consistent with [K-L-S]. The normalization in [M-P] is slightly different. If the information about the body K is uncomplete it is impossible to bring it exactly to the isotropic position. So, the definition of the ...

Abstract In this contribution, a model for the thermomechanically coupled behaviour of case hardening steel is introduced with application to 16MnCr5 (1.7131). The based on decomposition free energy into thermo-elastic and plastic part. Associated viscoplasticity, in terms temperature-depenent Perzyna-type power law, combination an isotropic von Mises yield function takes respect strain-rate de...

An experimental database of springback and twisting U-shaped elongated structures is available from a previous study. The materials are copper alloys: pure Cu, CuBe2, CuFe2P, provided in thin sheets thickness around 0.1 mm. After deep-drawing rectangular blanks, which can be aligned with the tools or slightly misaligned, tool withdrawal, structure exhibits an opening section (2D springback) (3D...

We propose an algorithm for the efficient parallel implementation of elastoplastic problems with hardening based on the so-called TFETI (Total Finite Element Tearing and Interconnecting) domain decomposition method. We consider an associated elastoplastic model with the von Mises plastic criterion and the linear isotropic hardening law. Such a model is discretized by the implicit Euler method i...