Based on the dominated deformation mechanisms of superplastic materials, an assumption for micro-damage evolution is presented. Then, a set of uni®ed viscoplastic-damage constitutive equations is proposed to model material hardening due to the increase of dislocation density and grain growth, as well as material softening due to intergranular void nucleation and growth. The effects of the harde...

The present paper is concerned with the development of a micromechanical model of the hardening, rate-sensitivity and thermal softening of b.c.c. crystals. In formulating the model we specifically consider the following unit processes: double-kink formation and thermally activated motion of kinks; the close-range interactions between primary and forest dislocations, leading to the formation of ...

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 ...

Shear instabilities in the form of shear bands are often observed during high speed, plastic deformations of metals. According to one theory, their formation is attributed to eeective strain-softening response, which results, at high strain rates, as the net outcome of the innuence of thermal softening on the, normally, strain-hardening response of metals. In order to test the core instability ...

an important concern in rock mechanics is non-homogeneity as joints or fault. adopting the joints as fractures, fractures are well known for their effects on the mechanical and transport properties of rock. it has been postulated that through fractured/jointed rock, mainly, the polygons turned to the shear vector (ti) are involved in the mobilization of shear resistance. consequently, in order ...