scholarly journals Effects of ThermoMechanical Coupling in Tribological Surface Transformations: A One-Dimensional Modelling Including Irreversible Solid-Solid Phase Transformations and Classical Plasticity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Grégory Antoni
Keyword(s):  
Yield Strength ◽  
Phase Transformations ◽  
Solid Phase ◽  
Thermomechanical Coupling ◽  
Lower Stress ◽  
Mechanical Loads ◽  
One Dimensional ◽  
Transformation Induced Plasticity ◽  
Compressive Loads ◽  
Classical Plasticity

Under compressive loads combined with friction, some materials undergo Tribological Surface Transformations (TSTs) on the surface of the loaded parts and in the immediately vicinity, which in the case of metals, are known as irreversible solid-solid phase transformations. During the solid-solid phase transformations occurring under mechanical loads, TRansformation Induced Plasticity (TRIP) processes are generated at much lower stress levels than those associated with the yield strength of the material in classical plasticity. In order to assess the effects of thermomechanical coupling in these TSTs, a one-dimensional modelling based on irreversible solid-solid phase transformations and classical plasticity is presented and discussed.

scholarly journals Return Mapping Algorithms (RMAs) for Two-Yield Surface Thermoviscoplastic Models Using the Consistent Tangent Operator

2018 ◽  
Vol 19 (7-8) ◽  
pp. 681-697 ◽  
Author(s):  
Grégory Antoni ◽  
Frédéric Lebon ◽  
Thierry Désoyer
Keyword(s):  
Phase Transformations ◽  
Solid Phase ◽  
Constitutive Models ◽  
Numerical Procedure ◽  
Flow Rule ◽  
Mapping Algorithms ◽  
Tangent Operator ◽  
Return Mapping ◽  
Classical Plasticity ◽  
Consistent Tangent Operator

AbstractThe return mapping algorithms (RMAs) presented here are designed for use with pressure-dependent thermoviscoplastic constitutive models involving irreversible effects associated with solid–solid phase transformations. During the volume solid–solid phase transformations occurring under mechanical loads, an “anomalous” plasticity, the so-called “TRansformation Induced Plasticity” (TRIP), is generated at much lower stress levels than those related to the yield stress of the material in the context of the classical plasticity. TRIP mechanisms are superimposed on the classical plasticity which is liable to occur in the case of metallic materials. Based on a non-standard generalized material framework, two different models are presented in which an “associative” plastic flow is introduced in the context of classical plasticity and a “non-associative” flow rule in the context of TRIP-like plasticity. In this paper, a complete algorithmic treatment of these two rate-dependent constitutive models is therefore proposed with the associated consistent tangent operator for dealing the quasi-surface irreversible solid–solid transformations which can appear in metal alloys during specific thermomechanical solicitations. The predictive abilities of the presented numerical procedure for modelling this kind of the irreversible solid–solid transformations involving two plasticity processes are tested and assessed by performing a two-dimensional finite-element analysis on some numerical examples.

Prediction of residual stresses in the heat affected zone

2004 ◽  
Vol 120 ◽  
pp. 705-712
Author(s):  
L. Taleb ◽  
S. Petit ◽  
J.-F. Jullien
Keyword(s):  
Residual Stresses ◽  
Phase Transformations ◽  
Thermal Cycle ◽  
Solid Phase ◽  
Axial Direction ◽  
Manganese Steel ◽  
Middle Zone ◽  
Finite Element Code ◽  
Transformation Induced Plasticity ◽  
The Face

In this paper the behavior of a disc made up of carbon manganese steel and subjected to an axisymmetric heating in its middle zone is considered. The applied thermal cycle generates localized metallurgical solid-solid phase transformations. Contrary to the study performed some years ago, the present work is concerned with relatively thick discs that lead to variable behavior according to axial direction. Experimentally, temperature and axial displacement of the face below have continuously been measured during tests. At the end of tests, the nature and the proportions of the final phases as well as residual stresses on both faces of the discs has also been assessed. These experimental results have been compared to numerical simulations using the finite element code ASTER, developed by Electricité de France (EDF), that enables to take into account the main mechanical consequences of phase transformations. From the obtained results it can be pointed out the significant importance to take into account the transformation induced plasticity (TRIP) phenomenon for better estimation of residual stresses.

scholarly journals Assessment of Thermomechanical Couplings in Tribological Surface Transformations: Application to the Irreversible Near-Surface Solid-Solid Phase Transformations

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Grégory Antoni
Keyword(s):  
Phase Transformations ◽  
Solid Phase ◽  
Thermomechanical Coupling ◽  
Near Surface ◽  
Thermomechanical Couplings ◽  
Coupling Processes

Tribological Surface Transformations (TSTs), which are irreversible near-surface solid-solid phase transformations, tend to occur on railroads frequented by heavy freight trains. The present study is proposed to assess the contribution of thermomechanical coupling processes to the emergence and development of TSTs near the surface of the rails.

Heat capacities and enthalpies of fusion and transformation for solvates of some salts with dimethyl sulfoxide and dimethylformamide

1988 ◽  
Vol 53 (12) ◽  
pp. 3072-3079
Author(s):  
Mojmír Skokánek ◽  
Ivo Sláma
Keyword(s):  
Heat Capacity ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Dimethyl Sulfoxide ◽  
Liquidus Temperature ◽  
Molar Heat Capacity ◽  
Solid Phase ◽  
Zinc Nitrate ◽  
Heat Capacities ◽  
Liquid Phases

Molar heat capacities and molar enthalpies of fusion of the solvates Zn(NO3)2 . 2·24 DMSO, Zn(NO3)2 . 8·11 DMSO, Zn(NO3)2 . 6 DMSO, NaNO3 . 2·85 DMSO, and AgNO3 . DMF, where DMSO is dimethyl sulfoxide and DMF is dimethylformamide, have been determined over the temperature range 240 to 400 K. Endothermic peaks found for the zinc nitrate solvates below the liquidus temperature have been ascribed to solid phase transformations. The molar enthalpies of the solid phase transformations are close to 5 kJ mol-1 for all zinc nitrate solvates investigated. The dependence of the molar heat capacity on the temperature outside the phase transformation region can be described by a linear equation for both the solid and liquid phases.

One-dimensional structured phase transformations under prescribed loads

1985 ◽  
Vol 15 (2) ◽  
pp. 133-142 ◽  
Author(s):  
Jack Carr ◽  
Morton E. Gurtin ◽  
Marshall Slemrod
Keyword(s):  
Phase Transformations ◽  
One Dimensional

Reactivity in solid phase. Transformations of 2,4-di-tert-butylphenol and its derivatives under elastic deformation conditions

1996 ◽  
Vol 45 (6) ◽  
pp. 1428-1432
Author(s):  
V. B. Vol'eva ◽  
I. S. Belostotskaya ◽  
A. Yu. Karmilov ◽  
N. L. Komissaroya ◽  
V. V. Ershov
Keyword(s):  
Phase Transformations ◽  
Elastic Deformation ◽  
Solid Phase

scholarly journals Mathematical analysis of hydrodynamics and tissue deformation inside an isolated solid tumor

2018 ◽  
Vol 45 (2) ◽  
pp. 253-278 ◽  
Author(s):  
Meraj Alam ◽  
Bibaswan Dey ◽  
Sekhar Raja
Keyword(s):  
Solid Tumor ◽  
Solid Phase ◽  
Fluid Motion ◽  
Extracellular Fluid ◽  
Mixture Theory ◽  
Coupled System ◽  
Weak Sense ◽  
Governing Equations ◽  
One Dimensional ◽  
2D And 3D

In this article, we present a biphasic mixture theory based mathematical model for the hydrodynamics of interstitial fluid motion and mechanical behavior of the solid phase inside a solid tumor. The tumor tissue considered here is an isolated deformable biological medium. The solid phase of the tumor is constituted by vasculature, tumor cells, and extracellular matrix, which are wet by a physiological extracellular fluid. Since the tumor is deformable in nature, the mass and momentum equations for both the phases are presented. The momentum equations are coupled due to the interaction (or drag) force term. These governing equations reduce to a one-way coupled system under the assumption of infinitesimal deformation of the solid phase. The well-posedness of this model is shown in the weak sense by using the inf-sup (Babuska?Brezzi) condition and Lax?Milgram theorem in 2D and 3D. Further, we discuss a one-dimensional spherical symmetry model and present some results on the stress fields and energy of the system based on ??2 and Sobolev norms. We discuss the so-called phenomena of ?necrosis? inside a solid tumor using the energy of the system.

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