Constitutive equations for the multiaxial stress-strain behavior of aluminum alloy 5754 sheets were developed, based on crystal plasticity. A Taylor-based polycrystal plasticity model, a tangent formulation of the self-consistent viscoplastic model (VPSC), and an N-site viscoplastic model based on the fast Fourier transform (VPFFT) were used to fit a single slip system hardening law to the avai...

We investigate the cyclic behavior of laminate microstructures in finite-strain crystal plasticity and the resulting stress-strain response, based on a variational, incremental description of the microstructure evolution. The nonconvex free energy density in multiplicative singleand multi-slip plasticity gives rise to the formation of fine-scale deformation structures, experimentally observed a...

In this paper, rod drawing process of strain-hardening materials is investigated by analytical, numerical and experimental methods. The classic upper bound solution, based on the assumption of perfect plasticity, has been extended to consider the work-hardening of the material during the drawing process. For a given process conditions and mechanical properties of the rod material, the power ter...

The goal of this research is to study the anisotropic material behavior during forming processes, represented by both complex yield loci and kinematic-isotropic hardening models. A first part of this paper describes the main concepts of the ‘Stress-strain interpolation’ model that has been implemented in the non-linear finite element code Lagamine. This model consists of a local description of ...

in this work, dynamic mechanical properties of three high-manganese steels with trip/twip or fully twip characteristics are studied. high strain rate experiments in the range of true strain rates between ~500 and 1800 /s are conducted using a dynamic torsional testing setup. all the three steels show a positive strain rate sensitivity in the intermediate range of strain rates (up to 500 /s). bu...

This paper analyses the influence of residual stresses and strain hardening due to the cold rollforming process on the load carrying capacity of perforated rack columns. First of all, a residual strain distribution of the manufacturing process is obtained via a finite element analysis and then it is introduced in the model as initial state to carry out a nonlinear buckling analysis. Two differe...

Steady state crack propagation produce substantial plastic strain gradients near the tip, which are accompanied by a high density of geometrically necessary dislocations and additional local strain hardening. Here, the objective is to study these gradient effects on Mode I toughness of a homogeneous rate-sensitive metal, using a higher order plasticity theory. Throughout, emphasis is on the tou...

The thermomechanical problem involving simple shearing of a finite slab made of an isotropic and viscoplastic material is studied with the objective of finding the e&t of the strain hardening parameter, strain-rate hardening parameters, thermal softening coeflicient and thermal conductivity on the initiation and growth of adiabatic shear bands. The body is placed in a hard loading device, i.e. ...

In the realm of multi-axial ratcheting, a step by step mathematical approach is developed for the parameter determination of decomposed kinematic hardening rules. For this purpose, key characteristics are mathematically derived for these hardening rules under multi-axial loading. These characteristics are then utilized to develop expressions which relate the loading history to the accumulated p...