Plasticity: from Crystal Lattice to Macroscopic Phenomena

New representations concerning plasticity physics in crystals are discussed. The model of plastic flow is suggested, which can describe its main regularities. With the use of the experimental investigation, it is shown that the plastic flow localization plays the role in the evolution of plastic deformation. Obtained data are explained with the application of the principles of nonequilibrium-systems’ theory. The quasi-particle is introduced for the description of plasticity phenomenon. It is established the relation between plasticity characteristics of metals and their position in Periodic table of the elements. A new model is elaborated to address localized plastic-flow evolution in solids. The basic assumption of the proposed model is that the elementary plasticity acts evolving in the deforming of medium would generate acoustic emission pulses, which interact with the plasticity carriers and initiate new elementary shears. As found experimentally, the macrolocalization of plastic flow involves a variety of autowave processes. To address the phenomenon of localized plastic-flow autowaves, a new quasi-particle called ‘autolocalizon’ is introduced; the criterion of validity of the concept is assessed.

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Quasi-Particle Approach to the Autowave Physics of Metal Plasticity

Metals ◽

10.3390/met10111446 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1446

Author(s):

Lev B. Zuev ◽

Svetlana A. Barannikova

Keyword(s):

Plastic Deformation ◽

Plastic Flow ◽

Flow Localization ◽

Quasi Particle ◽

Metal Plasticity ◽

Autowave Process ◽

Plastic Flow Localization ◽

Localization Of Plastic Deformation ◽

Particle Approach

This paper is the first attempt to use the quasi-particle representations in plasticity physics. The de Broglie equation is applied to the analysis of autowave processes of localized plastic flow in various metals. The possibilities and perspectives of such approach are discussed. It is found that the localization of plastic deformation can be conveniently addressed by invoking a hypothetical quasi-particle conjugated with the autowave process of flow localization. The mass of the quasi-particle and the area of its localization have been defined. The probable properties of the quasi-particle have been estimated. Taking the quasi-particle approach, the characteristics of the plastic flow localization process are considered herein.

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Autowave Mechanics of Plastic Flow

Springer Tracts in Mechanical Engineering - Multiscale Biomechanics and Tribology of Inorganic and Organic Systems ◽

10.1007/978-3-030-60124-9_12 ◽

2020 ◽

pp. 245-274

Author(s):

Lev B. Zuev

Keyword(s):

Plastic Flow ◽

Flow Localization ◽

Quasi Particle ◽

Plastic Properties ◽

Plastic Flow Localization ◽

Autowave Propagation ◽

Strain Invariant ◽

Deformation Hardening ◽

Set Up ◽

Flow Stage

AbstractThe notions of plastic flow localization are reviewed here. It have been shown that each type of localized plasticity pattern corresponds to a given stage of deformation hardening. In the course of plastic flow development a changeover in the types of localization patterns occurs. The types of localization patterns are limited to a total of four pattern types. A correspondence has been set up between the emergent localization pattern and the respective flow stage. It is found that the localization patterns are manifestations of the autowave nature of plastic flow localization process, with each pattern type corresponding to a definite type of autowave. Propagation velocity, dispersion and grain size dependence of wavelength have been determined experimentally for the phase autowave. An elastic-plastic strain invariant has also been introduced to relate the elastic and plastic properties of the deforming medium. It is found that the autowave’s characteristics follow directly from the latter invariant. A hypothetic quasi-particle has been introduced which correlates with the localized plasticity autowave; the probable properties of the quasi-particle have been estimated. Taking the quasi-particle approach, the characteristics of the plastic flow localization process are considered herein.

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A Normal Force-Displacement Model for Contacting Spheres Accounting for Plastic Deformation: Force-Driven Formulation

Journal of Applied Mechanics ◽

10.1115/1.1305334 ◽

1999 ◽

Vol 67 (2) ◽

pp. 363-371 ◽

Cited By ~ 105

Author(s):

L. Vu-Quoc ◽

X. Zhang ◽

L. Lesburg

Keyword(s):

Plastic Deformation ◽

Plastic Flow ◽

Normal Force ◽

Contact Point ◽

Continuum Theory ◽

Spherical Particles ◽

Proposed Model ◽

Deformation Force ◽

Displacement Model ◽

Force Displacement

In this paper, we present a simple and accurate model for the normal force-displacement (NFD) relation for contacting spherical particles, accounting for the effects of plastic deformation. This NFD model, based on the formalism of the continuum theory of elastoplasticity, is to be used in granular flow simulations involving thousands of particles; the efficiency of the model is thus a crucial property. The accuracy of the model allows for an accurate prediction of the contact force level in the plastic regime. In addition to being more accurate than previously proposed NFD models, the proposed NFD model also leads to more accurate coefficient of restitution that is a function of the approaching velocity of two particles in collision. The novelty of the present NFD model is the additive decomposition of the contact-area radius, and the correction of the curvature of the particles at the contact point due to plastic flow. The accuracy of the proposed model is validated against nonlinear finite element results involving plastic flow in both loading and unloading conditions. [S0021-8936(00)03102-0]

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Кинетика развития паттернов макролокализации пластического течения металлов

Физика твердого тела ◽

10.21883/ftt.2018.07.46123.020 ◽

2018 ◽

Vol 60 (7) ◽

pp. 1358

Author(s):

Л.Б. Зуев ◽

С.А. Баранникова ◽

Б.С. Семухин

Keyword(s):

Plastic Deformation ◽

Acoustic Emission ◽

Plastic Strain ◽

Plastic Flow ◽

Strain Localization ◽

Plastic Distortion ◽

Localization Zone ◽

Distortion Tensor ◽

The Relationship

AbstractThe features of the macroscopic inhomogeneity of plastic deformation in the form of autowaves with a pulsating amplitude are analyzed, and data on the localization of sources of acoustic emission at different stages of plastic flow in the stretching of fcc mono- and polycrystals are presented. The relationship between the local components of the plastic distortion tensor in the strain localization zone is traced. The role of acoustic phenomena accompanying the localization of plastic strain in the development of the process of plastic deformation is considered.

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The model of plastic deformation and failure of solids

Izvestiya vysshikh uchebnykh zavedenii. Fizika ◽

10.17223/00213411/64/9/75 ◽

2021 ◽

pp. 75-83

Author(s):

L.B. Zuev ◽

◽

V.V. Gorbatenko ◽

L.V. Danilova ◽

◽

...

Keyword(s):

Plastic Deformation ◽

Acoustic Emission ◽

Plastic Flow ◽

Work Hardening ◽

Scale Level ◽

Macroscopic Scale ◽

Deformation And Failure ◽

New Model ◽

Hardening Law

The new model is proposed to explain localized plasticity and failure development in solids. This is based on the idea about the interaction of plasticity acts with acoustic emission pulses. They are generated in the course of the elementary plasticity acts. It is shown experimentally that plastic flow is always localized on the macroscopic scale level. The distribution of localization in the volume has the form of different autowave processes and depends on the work hardening law.

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Multiscale Analysis of Acoustic Emission during Plastic Flow of Al and Mg Alloys: From Microseconds to Minutes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.204 ◽

2014 ◽

Vol 783-786 ◽

pp. 204-209 ◽

Cited By ~ 3

Author(s):

Mikhail Lebyodkin ◽

Ivan V. Shashkov ◽

Tatiana Lebedkina ◽

Vladimir S. Gornakov

Keyword(s):

Plastic Deformation ◽

Acoustic Emission ◽

Plastic Flow ◽

Nonlinear Dynamical Systems ◽

Crystal Defects ◽

Mg Alloys ◽

Collective Effects ◽

Experimental Conditions ◽

Nonlinear Dynamical ◽

Individual Crystal

Recent studies of plastic deformation using high-resolution experimental techniques bear witness that deformation processes are often characterized by collective effects emerging on an intermediate scale between the scales describing the dynamics of individual crystal defects or the macroscopic plastic flow. In particular, the acoustic emission (AE) reveals intermittency of plastic deformation in various experimental conditions, which is manifested by the property of scale invariance, a characteristic feature of self-organized phenomena. Some materials, e.g., Al or Mg alloys, display a macroscopic discontinuity of plastic flow due to the Portevin-Le Chatelier effect or twinning. These materials are therefore of special interest for the study of collective effects in plasticity. The present work reviews the results of a multiscale investigation of AE accompanying plastic deformation of such model alloys. The AE is analyzed by methods borrowed from the theory of nonlinear dynamical systems, including statistical and multifractal analyses.

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MANUFACTURE INVESTIGATION OF CARTRIDGE WITH BOTTOM-MOST PART FLANGE BY DIRECT EXTRUSION WITH COUNTERPUNCH. REPORT 13. DETERMINATION OF DEFORMED STATE UNDER STRAITENED EXTRUSION IN FOURTH CENTRAL AREA OF PLASTIC DEFORMATION

Technology of metals ◽

10.31044/1684-2499-2020-0-4-43-51 ◽

2020 ◽

Vol 0 (4) ◽

pp. 43-51

Author(s):

A. L. Vorontsov ◽

◽

I. A. Nikiforov ◽

Keyword(s):

Plastic Deformation ◽

Plastic Flow ◽

Central Area ◽

Direct Extrusion ◽

Deformed State ◽

Cumulative Deformation ◽

The Given ◽

General Method

Formulae have been obtained that are necessary to calculate cumulative deformation in the process of straitened extrusion in the central area closed to the working end of the counterpunch. The general method of plastic flow proposed by A. L. Vorontsov was used. The obtained formulae allow one to determine the deformed state of a billet in any point of the given area. The formulae should be used to take into account the strengthening of the extruded material.

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Numerical Study of Elasto-Plastic Hydraulic Fracture Propagation in Deep Reservoirs Using a Hybrid EDFM–XFEM Method

Energies ◽

10.3390/en14092610 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2610

Author(s):

Wenzheng Liu ◽

Qingdong Zeng ◽

Jun Yao ◽

Ziyou Liu ◽

Tianliang Li ◽

...

Keyword(s):

Plastic Deformation ◽

Iterative Method ◽

Hydraulic Fracture ◽

Iterative Procedure ◽

Fracture Propagation ◽

Hydraulic Fractures ◽

Zone Model ◽

Dilatancy Angle ◽

Proposed Model ◽

Hydraulic Fracture Propagation

Rock yielding may well take place during hydraulic fracturing in deep reservoirs. The prevailing models based on the linear elastic fracture mechanics (LEFM) are incapable of describing the evolution process of hydraulic fractures accurately. In this paper, a hydro-elasto-plastic model is proposed to investigate the hydraulic fracture propagation in deep reservoirs. The Drucker–Prager plasticity model, Darcy’s law, cubic law and cohesive zone model are employed to describe the plastic deformation, matrix flow, fracture flow and evolution of hydraulic fractures, respectively. Combining the embedded discrete fracture model (EDFM), extended finite element method (XFEM) and finite volume method, a hybrid numerical scheme is presented to carry out simulations. A dual-layer iterative procedure is developed based on the fixed-stress split method, Picard iterative method and Newton–Raphson iterative method. The iterative procedure is used to deal with the coupling between nonlinear deformation with fracture extension and fluid flow. The proposed model is verified against analytical solutions and other numerical simulation results. A series of numerical cases are performed to investigate the influences of rock plasticity, internal friction angle, dilatancy angle and permeability on hydraulic fracture propagation. Finally, the proposed model is extended to simulate multiple hydraulic fracture propagation. The result shows that plastic deformation can enhance the stress-shadowing effect.

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