dual phase steels with different martensite volume fraction and morphology were tensile tested at a temperature range of 25 to 5500c. stress-strain curves of all steels showed serration flow at temperatures of 250 and 3500c, and smooth flow at the other temperatures. both yield and ultimate tensile strengths increased with increasing testing temperature up to about 4500c and then decreased at h...

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 ...

Describing the moment rotation (M/θ) behavior of reinforced concrete (RC) hinges is essential in predicting the behavior of RC structures under severe loadings, such as under cyclic earthquake motions and blast loading. The behavior of RC hinges is defined by localized slip or partial interaction (PI) behaviors in both the tension and compression region. In the tension region, slip between the ...

a constitutive model based on two–dimensional unstructured galerkin finite volume method (gfvm) is introduced and applied for analyzing nonlinear behavior of cracked concrete structures in equilibrium condition. the developed iterative solver treats concrete as an orthotropic nonlinear material and considers the softening and hardening behavior of concrete under compression and tension by using...

to investigate the hot deformation behavior of 17-7 ph stainless steel, hot compression tests were carried out at the temperatures of 950, 1050 and 1150 oc and strain rates of 0.001 s-1 to 0.1 s-1. accordingly, the hot working behavior was studied by the analyses of flow stress curves, work hardening rate versus stress curves, exponent- type constitutive equations and deformed microstructures. ...

Modeling of the evolution of distributed damage such as microcracking, void formation, and softening frictional slip necessitates strain-softening constitutive models. The nonlocal continuum concept has emerged as an effective means for regularizing the boundary value problems with strain softening, capturing the size effects and avoiding spurious localization that gives rise to pathological me...

Ripples present in free standing graphene have an important influence on the mechanical behavior of this two-dimensional material. In this study, we show through nanoindentation simulations, how out-of-plane displacements can be modified by strain, resulting in softening of the membrane under compression and stiffening under tension. Irradiation also induces changes in the mechanical properties...