2219 aluminum alloy is a kind of high-strength Al-Cu-Mn that can be strengthened by heat treatment. Its mechanical property parameters and forming properties are greatly affected the deformation rate, temperature strain. Taking extruded bar as research object, Gleeble-3500 thermomechanical simulator was used to analyze thermal compression behavior under different temperatures strain rates. The ...

Abstract. In this study the yield point phenomenon in Bake-Hardening grade steel is predicted using a physically based thermo-mechanical model. A modified Taylor equation proposed with dislocation density evolution approach. The softening that follows higher incorporated Voce type decaying exponential function. strain rate dependency of plastic hardening also decay function dependent but does n...

Transient finite coupled thermomechanical simple shearing deformations of a block made of an elastothermoviscoplastic material that exhibits strain and strain-rate hardening, and thermal softening are studied by using the meshless local Bubnov–Galerkin method. A local nonlinear weak formulation and a semidiscrete formulation of the problem are derived. The prescribed velocity at the top and the...

This article presents two methods to evaluate and draw distinction among general cooperative aggressive strategic behavior in the iterated prisoner’s dilemma (IPD). The first method identifies classes of strategies, clusters them into subclasses based on their or disposition, then comprehensively assess behavior. second relies applying transformative manipulations that soften harden strategies ...

The material properties of OFHC copper film was investigated with the High-Speed Material Micro Testing Machine (HSMMTM) at the high strain rates. The rate-dependent stress-strain curves from the experiment and the Johnson−Cook curve fitting showed large discrepancies as the plastic strain increases since the constitutive model implies no rate-dependent strain hardening effect. A new constituti...

This paper derives kinematic admissible bending moment – axial force (M-P) interaction relations for mild steel by considering strain hardening idealisations. Two models for strain hardening – Linear and parabolic have been considered, the parabolic model being closer to the experiments. The interaction relations can predict strains, which is not possible in a rigid, perfectly plastic idealizat...

Constitutive equations of cyclic strain and stress softening for materials with low internal stress levels are derived from the rate theory. The study shows that over the high stress and low temperature range where the description of plastic flow in cyclic softening can be approximated with activation over a single energy barrier, cyclic strain softening is well related to stress relaxation pro...