Статья поступила в редакцию 12.01.12. Ред. рег. № 1175 The article has entered in publishing office 12.01.12. Ed. reg. No. 1175
PACS 46.05.+b 46. 62.20.D-46.25.-y 46.40.-f
ПРЕДСТАВЛЕНИЕ МОДЕЛЕЙ УПРУГОСТИ СПЛОШНОЙ СРЕДЫ ДЛЯ ГЕТЕРОГЕННЫХ СРЕД. ПРИМЕНЕНИЕ МНОГОМАСШТАБНОЙ ФИЗИКИ МНОГОФАЗНЫХ И НЕОДНОРОДНЫХ СРЕД, ИЕРАРХИЧЕСКОЙ МАТЕМАТИКИ
1 12 3
В. С. Травкин , Н.Н. Болотина', А.Л. Гусев
'Иерархическая Многомасштабная Физика и Технологии Лос-Анджелес, США Тел.: +303-808-9235, e-mail: travkin@travkin-hspt.com 2Университет прикладных наук Рейнбах, Германия E-mail: Natalya.Bolotina@travkin-hspt.com 3НТЦ «TATA» 607190 Саров Нижегородской обл., ул. Московская, д. 29 Тел.: (831-30) 6-31-07, e-mail: gusev@hydrogen.ru
Заключение совета рецензентов: 28.01.11 Заключение совета экспертов: 10.02.12 Принято к публикации: 15.02.12
Настоящая статья является первой из серии об основах явлений теории упругости в двухмасштабных гетерогенных сплошных средах и их моделировании. Так получилось, что со времени определения и выработки первых результатов в 1994-96 гг. вместо внедрения в физическую механику сплошных сред из-за различных препятствий эти результаты не были опубликованы с целью лучшего изучения механики гетерогенных сред, особенно в области теории упругости для гетерогенных масштабных сред.
В коротком описании работ по теоретическому выводу «масштабных» математических формулировок для определения зависимостей между нагрузкой и напряжением на масштабах, относящихся к явлениям физики непрерывных гомогенных сплошных сред, и привнесения свойств, характеристик между этими явлениями для большего «общего», «осред-ненного» масштаба среды, мы описываем несколько сравнительных формулировок для характеристик упругости в двухмасштабных гетерогенных материалах.
Мы объясняем причины того, что концепции и правильные формулировки теории упругости для масштабных гетерогенных сред не поняты и не используются в современной механике сплошных гетерогенных сред. Следуя общеизвестным, стандартным методам, используемым в гомогенной теории упругости при выводе управляющих уравнений теории упругости, мы получаем управляющие уравнения упругости для верхнего, осредненного масштаба представлений теории упругости для гетерогенных сред.
Описываются также общие условия и особенности вывода уравнений упругости для биологических, мягких, податливых сред с течением и без него. Эти среды, состоящие из большего числа масштабов физического описания составляющих упругости для осредненных упругих и/или вязкоупругих тел, имеют свои естественные явления, которые обуславливают физику верхних масштабов среды.
Ключевые слова: гетерогенные среды, многомасштабный, полимасштабный, многомасштабное моделирование, упругость, гетерогенная упругость, биологическое моделирование, моделирование в физике, упругость мягких тел, теорема Гаусса-Остроградского, теорема WSAM, теория осреднения, HSP-VAT, перенос по масштабам, многомасштабная физика, биосреды.
PRESENTATION OF CONTINUUM MECHANICS ELASTICITY MODELS FOR HETEROGENEOUS MEDIA. THE POLYPHASE AND POLYDEFECT SCALE PHYSICS, HIERARCHICAL MATHEMATICS APPLIED
V.S. Travkin1, N.N. Bolotina1'2, A.L. Gusev3
'Hierarchical Scaled Physics and Technologies (HSPT)
Los Angeles, CA, USA Tel.: +303-808-9235, e-mail: travkin@travkin-hspt.com 2University of Applied Sciences Rheinbach, Germany E-mail: Natalya.Bolotina@travkin-hspt.com
3STC "TATA" 29 Moskovskaya str., Sarov, 607190, Russia Tel.: (831-30) 6-31-07, e-mail: gusev@hydrogen.ru (A.L.G.)
Referred: 28.01.11 Expertise: 10.02.12 Accepted: 15.02.12
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This paper is the first one in a series on the Fundamentals of Heterogeneous Two-Scale Solid State media, materials Elasticity phenomena theory and modeling.
Unfortunately, in lieu of an introduction to the continuum (physical) mechanics community at the time of creation in the 94-96 these results due to various obstacles were not published and used fully for the purpose of better studying the heterogeneous continuum mechanics, specifically in the domain of elasticity theory for heterogeneous scaled media.
After presentation of the short review of works related to theoretical deductions of "scaled" mathematical formulations seeking dependencies between the strains and stresses on the scale of like "continuum" physics phenomena and of the larger "bulk" scale medium communication of properties, we outline the few conceptual formulations for the two-scale connection of elasticity properties for heterogeneous materials.
We try to explain the reasons why the correct formulation for the scaled Heterogeneous media elasticity is not understood and used in contemporary Continuum Mechanics for Heterogeneous media. Following the regular, commonly known path for formulation of Homogeneous medium elasticity governing equations we derive in the same way the correct elasticity governing equations for the Upper, bulk, scale in a Heterogeneous medium.
We outline as well on this path the peculiarities of derivation of governing equations for biological floating, non-floating, soft media. Those media while consisting of a few more scales to reasonably consider as components of the bulk soft elastic and/or viscoelastic body, have natural components that dictate the physics of the Upper scale(s).
Keywords: heterogeneous media, multiscale, polyscale, multiscale modeling, elasticity, heterogeneous elasticity, biology modeling, physical model, soft solid elasticity, Gauss-Ostrogradsky theorem, WSAM theorem, averaging theories, HSP-VAT, scaleportation, polyscale physics, biomedia.
Introduction
Historical Observation and Heterogeneous Continuum Mechanics Some Principal Provisions
Most of the initial concepts and fundamental two-phase two-scale heterogeneous media elasticity dependencies and governing equations were first obtained in 1994-96.
Some of them were formulated during research on analytical and numerical simulation of two-phase two-scale HSP-VAT problems while for studies in the Ukraine.
We won't be analyzing here the theoretical, modeling trends in the solid state mechanics, particularly in the elasticity theory. We restrict ourselves with a few notes, because the substantial layer of the research regarding studies in heterogeneous solid state mechanics have been published some years ago in http://www.travkin-hspt.com/elastic/right.htm "Continuum Mechanics of Heterogeneous (Ht) Media; Elasticity, Plasticity."
We wrote there: "The unfortunate fact in the contemporary common knowledge continuum mechanics - The Homogeneous Continuum Mechanics (HCM), is that the treatment of the Heterogeneous Media, Matters being performed as that they are being indistinguishable from the Homogeneous media treatment!
In Continuum Mechanics through the last more than 40 years workers do not recognize the other then the accepted in HCM since ~ 50s-60s Homogeneous mathematical modes (not the theories we can name) by Beran, Hashin, Hill, among others and continued later in 70s-2000s by Mura, Nemat-Nasser and Hori, we name just a few (many can be mentioned for their sizeable input) English writing authors, with the substantial influence as seems throughout the publications of others."
No real objection we could observe in our websites and in the literature.
And we can stress out why? Because the ground for Heterogeneous formulations and studies does need to use the different mathematics for Heterogeneous media -Heterogeneous, Hierarchical mathematics of discontinued fields.
The Detailed Micro-Modeling - Direct Numerical Modeling (DMM-DNM) method used predominantly now as the most "full and correct" method for Upper scale models, is mostly incorrect for this purpose. Especially, when the effective properties and the upper scale characteristics sought as the calculated ones based on these Lower Scale model's solution fields or when compared with experiment or sought to be used for experimental basics.
The DMM-DNM is good for the Lower scale, but averaging and other operations for and over the Upper scale functions, operators, etc. done with the Homogeneous GO theorem are mostly wrong.
On the other hand, we would like to state again and again that the Homogeneous subject physics is just the genuine constituent part of the broader description of the Heterogeneous matter. And there is no contradiction in this statement.
Some parts from the above mentioned analytical materials, texts on solid state mechanics, elasticity theory for heterogeneous media can be seen with the references in the website - http://www.travkin-hspt.com. From those pertained to the solid state physics and solid state elasticity mechanics texts some recently were also published in the hard copy literature in [1, 2].
The Two scale HSP-VAT firstly obtained solutions, the exact ones for the most known few common textbooks problems, can be seen in - 1) "Classical Problems in Fluid Mechanics" http://www.travkin-hspt.com/fluid/03.htm; 2) "Classical Problems in Thermal Physics" http://www.travkin-hspt.com/thermph/ 02.htm; 3) "Globular Morphology Two Scale
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Electrostatic Exact Solutions" http://www.travkin-hspt.com/eldyn/glob1 .htm.
Then were obtained after 2002 the two-scale HSP-VAT even the analytical solutions of the following classical problems: 4) "When the 2x2 is not going to be 4 - What to do?" http://www.travkin-hspt.com/eldyn/ WhatToDo2.htm; 5) "Two Scale EM Wave Propagation in Superlattices - 1D Photonic Crystals" http://www. travkin-hspt.com/eldyn/photcrys1.htm; 6) "Two Scale Solution for Acoustic Wave Propagation Through the Multilayer Two-Phase Medium" http://www.travkin-hspt.com/acoustics/supercross.htm; 7) "Effective Coefficients in Electrodynamics" http://www.travkin-hspt.com/eldyn/edeffectivecoeff.htm.
All these cornerstone (and other two-scale) problems have not been solved for Upper (second) Heterogeneous scale since the first half of the XX century by other methods (given in textbooks the Lower Homogeneous scale "solutions" are wrongly attributed to the Upper Heterogeneous scale averaged fields). These solutions leave no chances for calculations or comparison with experiment of the Upper scale characteristics using the basis of Homogeneous GO. This has no sense, invalid for Heterogeneous problems. The experimental procedures used now are based on the homogeneous medium assumptions.
Some definitions of scaling related to the subject of continuum physics and modeling of heterogeneous media as scaled media
In this publication we will be dealing with the problems of multiscale, heterogeneous, nonlocal and nonlinear character in elasticity for solid and soft solid media.
In each technique employed now in the continuum mechanics elasticity science that has been developed through the periods from their conception in XX-th century, a number of assumptions and adjustments have been accepted that are so convenient in use that workers consider them as laws. This has been challenged through the last ~40+ years in different physical sciences, but solid state Hierarchical Scaled elasticity was researched and developed in underground because of the usual conservative mode of progress (bringing in the fundamental change in modi operandi) in physics, science generally.
Most of these improvements can be referred to the proper, stricter treatment of collective, interactive phenomena while taking heterogeneous matter for study. To this kind of phenomena/changes we can relate almost any action or process more complicated than collision of "mathematical" ball onto the "mathematical" wall, or movement and collisions of two "mathematical" balls, meaning particles, atoms or molecules in MD.
In all other nature prescribed cases the physical matters are of scaled or multiscale character by existence.
There is no substance of physical content in our known universe that is not a heterogeneous one. The question is at what scale down the matter is still
homogeneous? That answer we don't know yet. And taking the scale an Upper or Lower one, then we will have the Heterogeneous matter anyway.
The volume of the earth can be considered as homogeneous at the galaxy mean scale, meanwhile for our human experiences the earth scale object is a huge heterogeneous one.
Another example - the water which we can obviously consider as a homogeneous matter? While it is not, at an atomic and lower scales.
As always, we need taking into account these physical characteristics of a matter description that always hold and are promoted for future description quality improvements, and sometimes for this quality change.
Also, in physics there is no action or process that we can name a local one, unless we want to. Otherwise, we have to look into the point and what it means more strictly. Obviously, many actions or processes can be separated from their less important, at the moment or case, surroundings or/and forces. But that is always more or less an artificial choice. Also we don't know yet -what is or not the collective influence of the Lower Scale forces, because up to now we connect the scales by approximations with the help of appropriate coefficients. All the laws in the past have been developed in this way.
We want the issues to be open for the inquiries and we ourselves have the right to inquire.
In this paper we won't be concerned to the multiscale, heterogeneous, nonlocal and nonlinear properties in solid state elasticity related to scales that are smaller, than what is used as of the continuum mechanics scales group ~(10-7-103) m.
Even for these ~10 orders of decimal magnitude the conventional homogeneous one scale physical theories provide mostly for the approximate or even ad-hoc adjusting mechanisms for the two-scale Bottom-Up scale communication, and that mode is to be re-entered in the current paper from the Bottom-Up and Top-Down interscale transport (communications) point of view. That says the connections of the scale inherited fields are of great significance/importance. We previously studied thoroughly in many sciences (fields) the contemporary homogeneous physics theories for heterogeneous matter and these reviews are referred below.
The strictest definition for the different scale related fields communication - transformation we suggested in 2004 as the Scaleportation.
Scaleportation is the means and procedures of the direct and strict "transformation" of data and processes at one scale to the data and processes of the neighboring Upper or Lower Scale. These interscale communications, scale transformations of data are performed mostly not by formulae using the coefficients as this is customary in homogeneous physics, but via using the interscale governing equations for the phenomena.
Scaleportation has being performed over the all our two-scale solved the HSP problems mentioned in this text and in the website - http://www.travkin-hspt.com, as
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the simulation methods that have been based on algorithms of analytical (exact) or numerical methods created for the direct Bottom-Up (BU) or Top-Down (TD) two-scale solutions.
When more than 2 neighboring scales of physical fields are involved, we have introduced the definition of a Scaleleaping (or Leapscaling).
At the same time, we compare and describe in some detail the true multiscaling mechanisms stemmed from the heterogeneous analogs of Gauss-Ostrogradsky theorem and scaled exact governing equations and solutions for classical homogeneous physical problems in different physical discipline fields that are under stable development path through the last more than 40 years.
It is the known information that all interatomic forces and consequently the upper meso-scale continuum mechanics phenomena can be explained by electromagnetic forces if starting from the lower atomic scale physics.
That means the attractive interactions named as the van der Waal forces (dipole-dipole and London) and hydrogen bonding, as well as Coulomb long range collective forces, in principle can be evaluated (and will be probably in the near future) via the field generating scaled (two scales [Sc]) governing equations that are much more depicting and are of much more accurate description. Thus, and much more difficult in simulation than use of any kind of potentials, Lennand-Jones forces, for example.
We won't count in the present report on the other potential relating actions and forces. That restriction is obvious at the beginning of polyscale language that establishing for the upper continuum mechanics scales in elasticity of solid state via the undeniable examples, problem considered solutions, etc.
It might help with the understanding of our approach to the more strict physically and mathematically description of many subjects of Heterogeneous, Scaled, and Hierarchical nature, made by nature itself from the atomic, molecular scale that the some knowledge of HSP-VAT (Hierarchical Scaled Physics - Volume Averaging Theory) can be of assistance.
To look through, one might browse our previous studies and analytical reports in other areas where the Heterogeneous, multiphase, scaled media and phenomena are in the core of subject matter, while this should help in estimation of the present solid state Heterogeneous Continuum Mechanics field -
http://www.travkin-hspt.com/fundament/03.htm Why is it Different from Homogeneous and other Theories and Methods of Heterogeneous Media Mechanics/(other Sciences) Description?
http://www.travkin-hspt.com/fundament/04.htm Are there any other Methods and Theories available?
http://www.travkin-hspt.com/fundament/pseudo.htm Pseudo-Averaging (Scaling, Hierarchy), Quasi-Averaging, Ad-hoc Averaging, and other "Averaging" (Scaling, Hierarchy) Type Claims;
http://www.travkin-hspt.com/urbp/exper.htm Experiments, Experimental Data Reduction and Analysis; Numerical Experiment (Simulation) Data Mining;
http://www.travkin-hspt.com/fundament/scaleport/ scaleport.htm Reductionism and/versus Holism in Physics and Biology - are Both Defective Concepts without Scaleportation;
http://www.travkin-hspt.com/thermph/heatconstruc/ heatconstruc.htm Pseudo-Science of Constructal Theory (Hierarchy) in Heat Transfer Modeling;
http://www.travkin-hspt.com/fluid/03.htm Classical Problems in Fluid Mechanics, other publications [3-8], etc.
Some parts from the above mentioned analytical materials, texts have been published also in the hard copy literature, see references in the website -http://www.travkin-hspt.com.
So far, as usual, in almost all the contemporary physics fields, but Fluid Mechanics and parts of Thermal physics, the tools and math used for Heterogeneous, Scaled, Hierarchical description are of the 30-50 years old, from the particle physics, statistical mechanics, and quantum mechanics when the spatial scales used are of 10-5-10-15m and less range.
All these tools of the one scale, homogeneous physics and math, just examples, we have found - have been done with the governing equations that were derived with the use of homogeneous Gauss-Ostrogradsky theorem. This is incorrect.
It would be appropriate to remind to young readers, that the similar to present (beginning of XX1-st century) "multiscaling" campaign had happened in the 80-90s of the last century. Then professionals in numbers went into public conferences with claims for a near or almost solved problem of so called "structure-properties" relation. That could not happen, because there was no base for structure-properties phenomenology even. Actually it was, because the VAT started in 1967, nevertheless, the true scaling VAT techniques, advanced mathematics, and solved hierarchical problems appeared only in 80-90s. With not much of interest from few professionals funded in the US and engaged at that time with HSP-VAT research.
That is why the "fashion" for "structure-properties" developments on 80-90s (XX-th century) went away with no results, unlike any other fashion.
Fundamentals of the theory
Some principal provisions, conceptual definitions, concepts of scaling matter related to the subject of
continuum elasticity physics and modeling of Heterogeneous solid media of two, at least, phase (components) as scaled media with physical and mathematical local scale strictness.
Principles of the Theory 1) Recognition of the fact - that at any scale the physical (biological) substance, tissue, material in the present theory, is the Polyphase Polyscale
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Heterogeneous medium. At atomic scale, sub-atomic, or at some of the continuum scales.
2) Recognition of the fact - that the structure and the "phase" content of a material sample are the fundamental facts controlling the function of the substance, material along with the environmental (boundary) conditions.
3) Recognition or knowledge that - in this consideration the polyphase, polyscale studying of the subject - the material, medium sample, is the most accurate and revealing way of obtaining the facts, conclusions. This was and is one of the main methods (the reductionism) to study the nature by physical methods by far for many centuries.
4) Recognition or knowledge of the fact - that for studying the polyphase matters, media the only correct way is to use the discovered in 60s - 80s methods, theorems of Hierarchical physics and mathematics: Hierarchical Scaled Physics - Volume Averaging Theory (HSP-VAT). Of many other methods suggested for the Heterogeneous media modeling and understanding, so far there is no one more fundamental and/or correct. We won't discuss or comment on numerous schemes suggested for heterogeneous, composite, polyphase media, as the mixture theory, for example, because they openly use an inadequate description of the problem.
This fact is not objected or disputed by any professional, openly at least for the last ~30 years. The complexity and educational policies preventing professionals to acquire and employ the tools of HSP-VAT.
One of the examples, is the use of Gauss-Ostrogradsky (GO) theorem for deduction of governing equations for near 200 years in physics and other sciences. This theorem is valid only for a Homogeneous matter. In hierarchical mathematics there are many like theorems for the same purposes that have been developed and used during the last 40 something years.
Hierarchical Polyphase Polyscale Concepts for
Heterogeneous Solid Media Elasticity Modeling
1) Any Heterogeneous media (Ht), materials sample is in reality a two scale, at least, physical entity that have continuous transport, physical field processes of a physical volumetric (averaged at some point) character.
2) It is not correct to study, model and make valuable definitive conclusions about this medium elasticity function when using only a one scale elasticity physical phenomenon(a) - as when mixture "theories" for heterogeneous media, are taken into account. Contemporary experimental physics, biology, medical investigations lack of ground and fundamental science, while applying the theoretical schemes of one scale nature that were suggested in physics many decades ago.
3) The scale models for heterogeneous media elasticity constitute the separate spatial and temporal physical and mathematical models describing the elasticity function relationships on the scale dependent phenomena in such media.
4) Scale dependent mathematical models are inherently communicative Up-and-Down over the scales in heterogeneous media. The scale communication of physical properties of Ht medium has been named as a scaleportation of properties and characteristics in HSP-VAT.
5) It is possible to commute the physical models and medium's properties at the neighbouring scales with mathematical strictness using methods developed in HSP-VAT.
6) Each scale developed Homogeneous models in a Ht medium based on Homogeneous presentation of this scale physical definitions and the field's governing equations can be connected more or less mathematically strictly to the neighbouring next Up-scale or Down-scale models only (most strictly) via using interscale mechanisms of HSP-VAT.
7) The polyscale depiction of Ht medium's function (elasticity) models is the only correct approach for theoretical modeling and simulation, for experiments data reduction when the subject of analysis, theory, model, experiment is the polyscale physically object with nature prescribed polyscaling of function.
8) Any Homogeneous (H) physical substance media, materials sample is in reality also of a two scale, at least, physical entity that have molecular (atomic) and continuous description of transport, physical field processes of a physical volumetric character. The averaging and scaleportation of molecular scale transport and phenomena Up- to the Continuum (one of continuum) scale Elasticity phenomena and Down- to the molecular scale, should be used with application of correct Hierarchical mathematics of discontinuous "broken" physical fields.
9) At present, in the last approximately 27-29 years all the main physical fields, definitions and homogeneous governing equations have been reformulated and upgraded using methods of HSP-VAT for acting in the heterogeneous subject matters, for Heterogeneous media of solids, solids and fluids, polyfluids, particles in fluid, scaled fluids, elasticity of solid and soft solid media, mass, heat, momentum, electromagnetism describing phenomena, wave mechanics, acoustical fields.
10) Advancements in the last 25 years in Hierarchical Scaled Physics - Volume Averaging Theory (HSP-VAT) allowed to surpass inadequate, incomplete one scale homogeneous theories for averaging (mixing), "bulk" representing theories in almost every field of physics. Now we can formulate the polyscale Elasticity theories and models for Ht medium objects and relevant processes, polyscale by nature in a Ht medium.
The local, non-local, and scaled metrics, physical fields, and their mathematical formulation
Claim: It is known that for every physical discipline serious mathematical formulation and modeling should have been used the theorem by Gauss-Ostrogradsky. This theorem formulates the connection in physical and
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mathematical sense via integration between the physical features, phenomena on the closing some volume continuous (outlined by us) surface and the phenomena within the embraced volume.
That means, it was already implicitly included the definitions of the two spaces and the two coordinate systems - of the initial integration of volume and over the surface and of the limiting (going to collapce the surrounded volume) mathematical expression between both, in the development of this field mathematical equations and models at each of the spaces agreed for consideration.
One is the scale that we perform the spatial integration - it theoretically can collapse into the point? But what is the point? What this point is representing?
The point is the subject without dimension in any direction, if in Cartesian coordinates, other 3D systems of spatial coordinates.
The lower scale (actually the same scale, but nonlocal) physics variables and properties then silently declared as irrelevant, unimportant - hereby we do not use, mention and mean that the point in our mathematical homogeneous formulation is actually the volume used in the GO theorem to obtain the current equation of interest. This approach is justified as soon as the matter assumed as of a homogeneous nature, because there are the mathematical theorems showing that the limit transitions when the size of a spatial domain collapses to an infinitely small one are presenting the properties of this domain in the selected internal point into which it collapses.
Meanwhile, we know that physics give us the very small objects - that constitute the body of any material -all these objects consist of atom and molecules.
That means, this conjecture for deduction of governing fundamental equations in physics via using the GO theorem where the volume should collapse to the volumeless point is defective.
And this precludes acceptance of the GO theorem for really applying to any physical matter, materials consisting of the atoms and molecules.
Because the GO theorem is mathematically valid for only Homogeneous matter - no atomic and molecular spatial Heterogeneity is accepted.
This surprised "discovery" actually "known" for many decades, since XIX-th century, when this approximation was starting to be used in Atomic era physics and chemistry at the beginning of XX century.
There were voices of awareness of this approximation, incorrect for any heterogeneous, polyphase media and materials.
Unfortunately, physicists (leading figures) in the past preferred not to notice this mathematical fact. Chemists followed the path.
Because it was convenient and because this "ignorance" gave the only chance to cover with some mathematical strictness of XIX-th century the whole body of physical consideration, more or less strict
"proof" of mathematical deductions related to Continuum Media (CM) mechanics.
And most of the media have been accepted as continuum ones, even in chemistry - when it is "known" that any chemical substance, and biological substance and material are discontinuous matters due to existence of their atomic structure.
More correctly is to say that in reality the more precise path for mathematical conventional deductions in physics was and is to consider the discontinuous function of physical substance of interest, when it is no way to do otherwise, because of the atomic structure of a matter.
And at the same time, when any mathematical operations need to be performed for that physical material - the tool of operation is the Continuum conjecture - this matter, material is accepted as a continuous one.
Following that premises physicists use the Homogeneous matter GO theorem and alike up to now in almost any physical theory. While this is incorrect.
The most influential and important forces acting on all atomic and Upper scales of physical matter, material are the electromagnetic (EM) forces.
We would accept with precautions in this paper the conventional classical set of Maxwell-Heaviside-Lorenz-Lorentz's (MHLL) EM homogeneous matter governing equations and based on them observed results that brought in and were justified in the HCM. We won't discuss here their validity and meaning.
Nevertheless, we have a prove that the electromagnetic phenomena mathematical expression governing equations used and discussed in many research areas of continuum media is an approximation of valid averaged sub-atomic MHLL governing equations - http://www.travkin-hspt.com/eldyn/ maxdown/maxdown.htm "What's Wrong with the Pseudo-Averaging Used in Textbooks on Atomic Physics and Electrodynamics for Maxwell-Heaviside-Lorentz Electromagnetism Equations".
It would be appropriate, meanwhile, to mention that at present exist a few points of view regarding the alternative systems for modeling electromagnetic phenomena developed by different researchers.
There are also the non-local homogeneous media properties. Those also use the basis of integration, or averaging. Integration is taken as for the continuous functions. This legitimate base allows us to approach the variety of media, materials, but only the Homogeneous ones.
For Heterogeneous media and materials there are exist the Heterogeneous Whitaker-Slattery-Anderson-Marle (WSAM) kind of theorems. And the reason for the definitions of at least two scale spaces and physics became the pivotal one.
This, in turn brings the problem of definitions for the point-like Lower and the point-like Upper scale physical fields. Consecutively, we need to define the non-local, averaged fields for stated Heterogeneous problems at their corresponding scales.
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We should obey to this original set of reasoning that was done two centuries ago in Physics and in Mathematics for the homogeneous media and translate it onto the heterogeneous, scaled media.
The great issue in all of this is the connection, communication between the physics and properties of each of the two spaces.
While for the homogeneous medium this question is seems never surfaced and discussed with application of the atomic scale discontinuous matter fields, for Heterogeneous media we need to specify these definitions with the greater detail.
After all, this is the key issue of scaling heterogeneous physics as it must work.
Thus, we start with the definition of a point, a dot used in the mathematical formulation of physical problems.
Definition 1 At the known and assigned previously system of coordinates the point is the object with no dimension in any of the three coordinates, and this object has the descriptive features, which determine the location of that point in the assigned system of coordinates. The point located physical property of the material has this spatial point determined value.
Following the GO theorem we now know that - if at any point with the coordinates inside of the problem's domain is known the functional dependency for a physical field, which in the most of physical sciences right now is the partial differential or just differential equation(s), then we imply that the domain which served for the derivation of this equation via the GO theorem was the domain of the Lower subspace - because in that theorem we start doing an integration over the finite volume and the finite surface(s).
Now - this principle can be applied to the heterogeneous media, which means - that after the averaging provided according to the one of the WSAM theorems - we get the mathematical equation (dependency) of the higher (another) space. With the corresponding spatial dependencies and the topology of the physical spatial fields.
With the one substantial different feature - it can not infinitely be reducing the size, the volume of this domain - because this volume needs to be kept with the most of descriptive features of the both (or more) phases inside of our spatial integration domain.
Definition 2 The Upper Space point when connected to the Lower Scale Domain might reflect, determine, and establish the features of communications between the both space physics. These features can be of different physical description in accordance to their respected space physics definitions. And vise versa - the Higher Space point physics might control, govern, reflect, and determine in some ways the properties of the Lower Scale physical Domain.
It is easier to discuss and argue in favor of these definitions right now - after the number of problems in various disciplines of physics were solved in the said mode - when the Lower and Upper scale HSP-VAT
governing equations were connected directly before and during their respected solutions - it has been shown by means of the two-scale solutions, especially with the exact two-scale solutions of some common textbooks known classical problems, see in - "Classical Problems in Fluid Mechanics" http://www.travkin-hspt.com/ fluid/03.htm; and in the above mentioned other web subsections.
Introductory to polyscale description in physics and technologies
Hierarchical Scaled Volume Averaging Theory (HSVAT) introductory concepts and theorems The basic idea of hierarchical medium description and modeling is to recognize that the physical phenomena, mathematical presentation of those phenomena, and their models can be very different at even neighboring scales. In most of situations those are different even if phenomena themselves are similar or looking as identical, but the scales are different and the lower scale features should be transported to the upper level of description (or Top-Down) - Fig. 1. With that action, the useful information from the lower scale physics would be added to the characteristics on the upper scale level.
Рис. 1. Представительные элементарные объемы (ПЭО) REV1 и REV2 в гетерогенной среде с заданными точками представления (х^ x2) на верхнем масштабе физического пространства. Форма (объемная) для ПЭО может быть не только сферической Fig. 1. Representative elementary volumes (REVs) REV1 and REV2 in a heterogeneous medium with the assigned points of
representation (xi, x2) at the upper scale physical space. The shape (volumetric form) of the REVs can be of not only spherical one
The following definitions were used in the 90s in solid state heterogeneous media elasticity theory (HtET) as well as at the earlier times for other sciences dealing with the scaled heterogeneous problems. The studies by Kushch and co-authors [9-15] will be used here as the
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example, the only one in the history of HtET as of the consequences of an attempted cooperation with already established mechanic theorist for the studies on HtET, thermal physics and fluid mechanics with implication of the HSP-VAT methods and know-how. It is the useful comparison for establishing the guideline, the path in the Homogeneous elasticity theory that has been used anyway by Kushch throughout these 15-something years studying the subject of HtET with the homogeneous elasticity mechanics methods.
The volume average value of one phase in a two phase composite medium <si(x)> in the REV and its fluctuations in various directions, its main physical and mathematical needs, definitions are determined, for example in [3-8], at first looking simple
si (x) = (si (x)) + si ) (s\) =
ДЦ ~ÄQ
Рис. 2. Упрощенная схема «снизу вверх» (телескопического) последовательного ряда представительных элементарных объемов (ПЭО) в 3 масштабах от молекулярного (один из ПЭО представлен в водном растворе) до масштабов сплошной среды. Важно, что ограничивающие пЭо поверхности не принадлежат (не проходят по) только одной выбранной фазе Fig. 2. Simplified draft of Bottom-Up consecutive series of Representative Elementary Volumes (REVs) at three scales from a molecular one (one of the REVs is in an aqueous solution) to continuum scales. Note, that the bounding REVs surfaces do not belong
to only the one singled out phase
The three types of two-phase medium averaging over the REV (Fig. 2) function f are defined by the following averaging operators arranged in the order of seniority
f = ( f)1 +( f) 2 = M f +(1 -( ) f„
where the phase averages are given by
f 1 = MA^f f (x)dm = wh
1 до1
f 2 = Ar f f ((,x)dro = to f»
A^2 AQ2
and the internal phase averaged functions are given by
{fI = f =AtJ f (t,x)d»;
1 ДЙ1
{f}2 = f2 = ^ J f (t>x)d» =
where f is an average over the space of phase one Aflj in the REV, f2 is an average over the second phase volume AQ2 = A^ - A^, and <f> is an average over the whole REV. There are also important averaging theorems for averaging of the spatial V operator -heterogeneous analogs of Gauss-Ostrogradsky theorem. Those are plenty already since 70-80s [16-24]. The first few of them needed to average the field equations are the WSAM theorem (after Whitaker-Slattery-Anderson-Marle) and the one is for the intraphase V averaging. The differentiation theorem for the intraphase averaged function reads
{f }i =Vf+^TJ
ДЦ
f = f - f, f VAQj,
where dSw is the inner surface in the REV, dsl is the second-phase, inward-directed differential area in the REV ( dsx = nl dS).
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2 ДП
The WSAM theorem sets the averaged operator V in accordance with
<V/>1 =V f) 1f^.
It can be shown that for the invariable morphology (<m> = const) of the medium the operator {Vf }1 can be presented also as
{vf} = V(f \ J fK when m
dSw
= const.
Meanwhile, the foundation for averaging made, for example, by Nemat-Nasser and Hori [25] (and many others) is based on conventional homogeneous Gauss-Ostrogradsky theorem (see pp.59-60 in [25]), not of its heterogeneous analogs as the WSAM theorem.
The following averaging theorem has been found for the rot operator
(Vxf>1 =V*<f>1 + ds1 xf ,
dS12
and as a consequence, the theorem for the intraphase average of (Vxf) is found to be
{Vxf} = Vx{f}1 + ds1 xf .
The averaged time derivative according to transport theorem forms in the heterogeneous medium the following mathematical equation for a phase one, for example,
where vector Vs is the velocity of the interface surface dS12.
Hierarchical Scaled Volume Averaging Theory (HSVAT) Operating Lemmas
When the interface is fixed in space the averaged functions for the first and second phase (as liquid f and solid s, for example, or two-phase solid) within the REV and over the entire REV fulfill the following conditions, namely
{f + g}f ={f }f +{g}f ; {a}f = a for the conditions of steady state phases = d{f f
dt
% }f = ffg f,
where a - a constant, except for the differentiation condition {Vf}1 and (Vf) 1, that is as written above in the two forms.
There is an important difference in the definitions of averaged and fluctuation values in regards of their meaning and values in the REV comparing to definitions supported by Whitaker and Quintard see, for example, [23, 26]. The treatment and interpretation of the averaged values inside of the REV are supported in the classical interpretation when a value, considered as an averaged inside of the Lower scale REV volume, is still the constant value within the same initial ground scale REV the assigned representation point xu for the Upper scale description space. The more detail on that problem are given in [18, 22, 27].
Some clearance to this difficult issue brings the concepts and formulation of the scaled problems in the two or more scales.
The intrinsic type of averaging {f} fulfill all four
of the above conditions as well as the following four consequences
{{I/ = f, {{}f = { - f I/ = 0;
{fg }f = ffg /, {/g}f = ffg / =
At the same time, (f)f and (f) do not fulfill neither the second of the averaging conditions for {f }f, with equalities
(f+g)f = (f)f+<g)f; {a)f * a; {a)f = im)a, while for stationary spatial volumes
f m,=fffc>f,
nor the consequences of the other averaging conditions
(f)f = (m)f, ^{f)f * /; (f)f = (f - f)t = °; {fg)f = mffgf, ^ (fg)f * ff; H=h g=°.
At present, the models of transport phenomena in heterogeneous media when using the HSP-VAT allow to treat media with the following features: 1) multi-scaled media; 2) media with non-linear physical characteristics; 3) polydisperse morphologies; 4) materials with phase anisotropy; 5) media with non-constant or field dependent phase properties; 6) transient problems; 7) presence of imperfect interface surfaces; 8) presence of internal (mostly at the interface) physico-chemical phenomena, etc.
More detail on the non-local VAT procedures and governing equations for different physical problems modeled in homogeneous media by linear mathematical physics equations can be found in publications [16-24, 28] and many other. Meanwhile, features depicting
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12
closure, nonlinear theory, polyphysics applications, polyscale developments, exact solutions, etc. were first advanced and can be found only in the works like [18, 22, 29-34] and mainly in the website http://www.travkin-hspt.com.
Averaging, Scale Statements and Scaling Metrics in Homogeneous and Heterogeneous Media Applications When one would write the recognized in many sciences (and in biology) the convective diffusion equation
dCf 2
—f- + V «VC, = D,V 2C,,
dt f f f
(1)
and the following one obtained in HSP-VAT as for the Upper scale averaged physical properties convective diffusion equation
dC 1
m -ff (c)+vCf=-v(C fu )f+
+Df V«(V( m)C f) + Df V«
- f C fds
A&1 f
D
f Vc,«ds, AQ J f
(2)
until recent times (80s) it was hardly to be noticed that these equations are perfectly connected and by not only similar notations for concentration and velocity fields, but through the physical scales interaction mainly.
Comparison of equation (1) and one of the perfectly legitimate upper scale HSP-VAT heterogeneous medium mass transport equation (2) gives a ground for a number of observations which are critical for understanding and proper application of HSP-VAT scaled mathematical models. When one analyzes, for example, equations (1) and (2) it should be up front a clear understanding of what does the global dependence through the interface of coefficient Df mean ?
1) Is this the piece-wise constant in each of the phase function? Is the jump condition present on an interface?
2) Is this the piece-wise constant function with the relatively smooth but very thin transition layer of interface?
3) The most important question is - are those interface physics phenomena so important qualitatively or quantitatively that their influence should be found in the governing modeling equations ?
The answers to these questions are laying mostly in the physics of another (smaller) scale and they are not ready for analysis in most of the problems.
Studies of the two-scale problems in HSP-VAT [18, 22, 29, 30, 31-34, etc.] concerning the thermal macroscale physics and fluid mechanics in capillary and globular heterogeneous (porous) medium morphologies demonstrated that even when interface transport has no openly declared physical special features as, for example, surficial transport - longitudinal diffusion or adsorption, etc., the input of additional surficial and fluctuation terms in the upper scale VAT equations
solutions can be significant, reaching the same order in magnitude in balance, as traditional diffusion, heat exchange or friction resistance terms input.
That means - the another non-traditional scaled physical effects are exist and we need to take this into consideration when building the two (or more) scale physical model, experiment, optimize the structure.
More importantly is to have the lower scale physics of the interface included in the upper scale governing equations when this physics is somehow different from physics of upper scale. In electrodynamics those are, for example, effects of polarization on interface surface, surficial longitudinal waves or current, surface plasmons, etc.
Meanwhile, there is no other theory or approach which could include within itself the governing equations formulations of the physical phenomena from neighboring lower or upper scale description. We are not talking here about source terms inclusion. The source term inclusion provided usually in the form of some analytical formulae to describe an effect when there is the lack of knowledge or resources, or no vital necessity in analyzing the coupled phenomena of different scales.
The most sought after characteristics in heterogeneous media transport which are the effective transport coefficients, can be correctly determined using the conventional definition as for the steady-state solid two-phase effective diffusivity D*, for example, with the one of possible formulae
-(qj = D'V(C) = D2V (0 + (( - D2 )-L f VCdrn ,
but only in the fraction of problems, even while employing the Detailed Micro-Modeling - Direct Numerical Modeling (DMM-DNM) exact solution that evidently requires the volumetric correct averaging (VAT averaging). The issue is that in a majority of problems, as for inhomogeneous, nonlinear coefficients, for example, and in many transient problems having the two-field, two-phase DMM-DNM exact solution is not enough to find effective coefficients, because the formulation of correct formulae is beyond the homogeneous physics method tools.
Thus, returning to equations (1) and (2) it should be clear understanding that the representative point (RP) of physical field component in (1) is the dot point of approximate size ~103 [nm3] (for our range of scales), which includes >0(106) atoms for a substance with the low molecular mass. Then the reasonable representative elementary HSP-VAT volume (REV) at the upper scale for the equation (2) can be about >(1-10) [^m3] = (1091012) [nm3], including within itself the thousands of lower scale RP volumes together with their structural elements, etc.
This REV volume would contain ~0(106)x(109-1012) = = 0(1015) atoms,
which is even for today's upper end high power supercomputers not a solvable MD problem. The important thing is that the algorithms of homogeneous
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MD techniques are integrating these volumetric effects incorrectly because of using the homogeneous GO theorem [2]. That means in a traditional homogeneous MD the Upper scale characteristics won't be analyzed properly anyway.
Still, the main reason, why equation (2) together with the lower level micro model (1) is the more correct tool to model the heterogeneous medium transport, is because it has the mechanisms (additional terms) which clear role is to connect physics of lower scale transport, often different from the upper scale, and morphology of the two-phase (or more) medium to its bulk effective properties and upper scale fields.
It is essential to take into consideration qualitative transformation of homogeneous conventional formulation of a process under investigation as, for example, the wave propagation problem into heterogeneous scaled (at least on two scales) problem as soon as the numerous structural objects which separate the phases are introduced by nature to the medium for any good reason.
Elasticity of solid heterogeneous media
We can make an averaging of the stress and strain components in the two-phase heterogeneous media to get the "effective" ones by finding the volumetric integrals for the strain zv (xk) and stress a v (xk) tensors
(e j) = V Je j (Xk )dV ;
V
j) = V Ía i (Xk)dV ,
(З)
(4)
scaleblending, where the hypothesis suggested as such -the remote constant assigned as initial value strain tensor (e.) which is in terms of averaged over the both phases, matrix m and particular phase p, value is
d = 1 + 1 = H { }m + (1 - m)K }p =
= (m)- f (u, . + u.,)d+
2AQ J v i'1 1 '
AQm
+ (1 -m)—1— f (u, , + u..)dœ = v ;2AQ J v 1 1 ''
p AQ p
Щ
(1 - m)
Im! 2
Í (Vu + (Vu)7)
m AQm
—^ Í (Vu + (Vu))dto
AQ p aQ pl '
— Í (Vu)dí^^ Í (Vufdro AQ i v ' 2 AQ„ i V '
(1 - m)
m AQm
А
(1 - m)
—^ Í (Vu)dю
AQ p aQp ,
—^ Í (Vu)7 dю
AQ„ i V '
p AQp
when being written in the general form of phase averaged fields has 4 additional surficial terms
( , A V .
AQ.
where the REV volume V is written here in a convenient notation used in homogeneous physics.
In the following introductory analysis of HSP-VAT formulations for elasticity theory for the two-scale heterogeneous media description, we would like to use the simple two-phase matrix-particulate phases medium.
Strain averaged over the two phases of heterogeneous media
At first we would like to start from analysis and comparison of few averaging operators used for integration within the heterogeneous medium while applying both theorems the Gauss-Ostrogradsky and the WSAM.
We use to compare some results by Kushch et al. [11-15] for heterogeneous medium elasticity when used the GO theorem while the need is to put into operation the WSAM theorem and following two-scale statements with integro-differential equations. Meanwhile, most of analysis now is given in [4] while some notes are published in [1, 2]
In the study by Kushch et al. [13] authors has a pure notion of a feature that can be called as the
1
2
(u) ^ Í uds,
aq¿
Г Í 1 , __
(v (u) ) t - Í udsm
V N ,m' AQ J
V dSwm
V(u) +— Í udSp p AQ J
SSwp
Í 1 — (V H )) Íuds'
АГ А
V
1
2
Í
АГ А
(5)
because
AQ
— Í Vudю = {Vu} = (Vu) Q J L Jm m
1
(m)
í 1 -
V (u) t- Í uds.
x 'm AQj
(б)
and only because and if the boundary conditions of equality of displacements u|3S = u|3S and traction
vectors nm ctL = n p aL satisfied, which is not valid
m '<>Swm P '°Swp
for many real technological materials, we have the
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simplification as soon as and only if we consider the strain tensor averaging (e^ = + (e!/} , not the
stress averaging (a^ = (a^ + (a^ .
The simplification comes when we can write if displacements at the interface are equal
— f udsm =—^ f uds„ ; ao J AOJ
AO.
—— f udsm = - -— f uds
AO.J AO J
AO -
(7)
and we continue to deduct
(**) = 4 =
= 2 (V <«) „ ) + 1 (U> m J + 1 (V( U> ^ ) + i (V (U) = 2 (U>„ +Vu)p ) + ) (( (u)„ )T +(V(u) J
= 2 V^U) „ + <U> p ) + ) V(((U) „ )T + ((ll) p )))
= 1 V(u)) + 2 V((U) )T = 2 [V((U> )+V((u) )T
now, only now we can use the GO theorem because in this expression the averaging is about the whole REV as for homogeneous medium without internal phase divide
—^ f (nu) ds + —^ f (nu)T.
AOi v '" AOi v
1
ds
AO I V
UjUj + njUj
)ds
as soon as
dsm =-ds„ ; —^ f udsm =—— f udsp до J ло J
AO dS,m AO3S_
also we need to remember that
V( u) =—^ f udsm ; V (u) =—— f uds„
A" J „ P AO J „ P
(8)
(9)
(10)
1
+ —
2
j) = 2 u) m + (u) p ) + (V {u) m + V< u) p )
1 1 1 f 1 ^ - f udsm +— - f udsm
AOdSm„ J 2 lAOdi
1 - 1 1 f 1 -- I uds„ + — - I uds„
AO J p 2 AO J p
p iO J \ p iO
1 1 1 f 1 T
- f (num ) dsm +--f (num )..dsm
AO ^ m j m 2 AO J v m,'j
AO
= 1 = 2
AO-
— f (nu p ) dsp +1 —^ f (nu p ) ds
O J V p >a p 2 AO.J v p '4 '
— f (nu) ds+ —^ f (nu)T ds AO '
"it
AO J V
V
nUi + nu, )ds
AOgS V '
(11)
These mathematical deductions are the pure demonstrations of relationship between the homogeneous medium GO theorem and the WSAM theorem for heterogeneous medium.
That is, when the two (or more) volumetric phases having the interfaces and their volumes are designated to the selected REV, the combined (bulk) mathematical expressions for acting in each volume operator V can be, if summed, equal to the expressions obtained for the whole REV with the GO theorem.
But only for the V operator acting in expressions without any phase coefficient, for selected cases and for perfect interface boundary conditions.
Integration should be done only over the phase intersecting surfaces of bounding (outer) REV surface dS . which is
dS. =dS . =dS . ; dS =dS +dS . ;
io mi o pt o > p wp pt o >
dS =dS +dS„
dS = dS = 3S„
(12)
It is obtained the form of averaged strain in a full coincidence with the homogeneous elasticity theory because for this mathematical equation for strain there is no difference in expressions for both phases, the averaging is all over the bounding surface, and the interface surface 3S'w = dSwm = 3SKp physics is of perfect bond.
It can be written also via the surficial integrals of input-output dSmio and dSpio at the REV's bounding
surface dSio =dSmjo =dSpjo, that (e ¡^ can be expressed in these conditions of perfect bonds via
but not over all interfaces of the particles in the REV. That is the great difference with the Kushch's et al. [13] mathematics, see also in [1, 3].
And finally in the volumetric variables we have the formula for the strain averaged over the two phases
(e ,> = (e .1 +(B 4 =
= 1 V((( m + <U) p )+(U m +V U) p )) ) =
= 1V(<u> + (V (u) )T), (13)
while that is only because there are no physical properties assigned to the phases and the perfect interface BC were accepted.
Л
Л
+
2
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The general form of (e.) when used the phase
averaged fields and interface surface elasticity properties that are not of perfect traction and displacement conditions is
Ы = 1 +(ej)p =
=M Ы+(l - m){ei}p =
1 í 1 - А
V(u) t- Í uds
m AQ
1
2
Т í 1 — (V(u) ) t - Í uds»
lAQ¿
V (u) t — Í udsp
p aq dS
dSwp
(V H í + íAQÍ uds
1
2
АТ А J
АТ А
у
(14)
у
1 í 1 -
(е,Л = - V(u) t- Í uds
\ ¡Im 2 N 'm AQj
í Т í 1 , -- (V(u) ) t - Í uds,
: v x 'm> aqJ
А
1
2
АТ А
V
(15)
well, if we recognize that
V(u) =—^ Í uds„, m AQ
(1б)
then we can write this tensor via the total its interface surface within the REV as the following
(еЛ =1 Í udsm t—^ Í uds,
x .m 2[aqJ AQj
А
АТ í
чТ А
— Í uds» t —— Í uds, Q AQ
AQ
1 — А 1 í 1 —
- I uds» t — - I uds
AQ ¿ J 2 [AQ¿
AQÍ((n^ )j+(num )))
LÍ(< O j v
ds
n u. t n u. )ds AQdJ v ¡ J J ¡' m
óSm
(17)
m wm mio
via the total interface surface dSm = dSwm + 3S„,„ for the matrix phase.
Strain tensor averaged over the particulate phase
When strain tensor has been averaged over the another (particulate, or of other morphology) medium it has the formulation
Note, that it is never in need to use this averaging as a separate action from the physics' other aspects of the elasticity problem. The same can be said and on the averaging in Kushch et al. [11-15] and other works.
Nevertheless, when averaged separately over each phase the strain averaged expressions are different.
Strain tensor averaged over the matrix phase
Strain formulation equation over the matrix phase (in a two-phase medium) averaging is
(еЛ =1 V(u) t— Í uds \ Jp 2 N AQ J
((upÍ +^AL J uds
1
2
а
, t
j
ат а
AQ
^ 0Swp
(1S)
then we can write this tensor via the total its bounding surface within the REV
1
2
(еЛ =1 —^ Í udsp t—^ Í uds x iJ'p 2 AQ J AQ J
\ °Sp¡o °Swp
1 АТ í 1 А - I udsp t - I udsp
AQ J p AQ p
°Sp,o J V. °Sw
— Í ((nup) + (u j
aqJU "'a \ ?>.
Sp
Hniui t niui )ds ¡ J J ч
А
т А
(19)
where the total bounding surface for the particulate phase dSp =3SWp +3Spio.
Here the interface surface displacement averaged
tensor (u„) is
\ V! dS
(u„) = —^ Í udsm = —^ Í nudsm =
\ .dS AQ J.» AQ¿ m
=ALÍ(nu» ),ds»=al í (¡u» к. (20)
p
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Stress tensor averaging
For the stress relation averaged over the two-phase (a^ we should write the following mathematical expression
as soon as
Ы=№ ¿m+=jm)m+(J (¿m )d»+AO J ((¿n )
p AO ^
if and Cpu are the constant matrixes as in most of the studies accepted, then
Cm cp
ijkl I" ' ^
AO
J (¿m) dro+^O J (£p) dro_Cm ^+Ck ^
_1C.
ijkl
+—Cp ^ ~ ijkl
_ — Cm
2 ijkl
+—Cp
T 2 ijkl
Wu) +- f udsm + (v(u) ) + - f uds,
x 'm AO J v x 'm> ^AOj
V(u)p +AO J udsp +((u)p)Г +|A0 J udsp
V(u) +(V(u) ) +- J udsm + - J uds
\ ы \ \ Ы) AO .J AO J
AO.
T — —
V(u) +(v(u) ) +- J udsp + - J u
Wp V \ lp! AO J AO J
/
Y
_ — C
jkl
+—Cp
T T ijkl
V( u) m +(V( ^ m )T
V( u p +((u> p))
+—C
jkl
AO
(
idsp
+—Cp
> ^ ab
jkl
- J udsm + - J uds,
AOi lAOi
J uds„ + J udsp
AO,! , AO J
_ — C
ijkl
V (u)m +(V(u)m )T
+—Cp
> ^ ah
ijkl
7<u> p +(V (u) p)
plus the 4 surficial terms that appeared as the result of WSAM theorem applied
+—C
ijkl
—^ J udsm + —^ J uds, AO J AO J
Y
+ — Cp
_ — C
ijkl
J udsp + —^ J uds AO J p AO J
'(u)m +(V(u>m )T ] + ^Ck \v(u)p +(V(u>p ))
+ ^2(( - cp» )) J u^m + —(( - Cpu )(AO J udsm
9SWm V dSWm
'M m +(V M. )T ] + 2 j [V <»> „ +(V („) J
_ — C
— (( - Cp ) 2 \ ijkl ijkl)
—^ J udsm + —^ J uds, AO J AO J
Thus, we see here 4 more terms (last terms) than would not be expected in homogeneous CM. This is the final equation for the averaged over the two-phase stress tensor (a^ .
The VAT expression for (a^ generally as for two-phase medium can be written as
(2—)
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(CTv) ipijkl+ Cijkle kl) (Cijklekl) m + (pijkl Ejl)
AQí (()dю + ^í (e£)dю =
¿i" AQj
><^m +((^m )) ] +
W u j+(( u j):
—^ í u dsm + —^ í u ds, ЛО j ЛО j
= 1 с
+ - Cj
-1 (cm - Cj ) , y^ijkl ijkl)
AO-
AO-
. (22)
- 1 N
\а„/ =- í a-dю +-У í ajdю =
* j' AO J j AO ^ J j
AQ AOk AO 9=1 AO,
= i í C-kle-dю+77: У í Cwe+ldю j
AOAOj j AO £ aQ, j
Ck ^У í £+ldЮ + C-l ^У í Üd«>:
VAO7 ,=1 AO, VAQy ,= 1 AO,
1 Cj N
= C-,- í e„dю + —— У í e+ldю +
jkl AO AOj kl AO^ i, И
+ (( - C-l)]0У í e+ldю =
,=1 AO,
= C
ijkl
AO
N
í e-ldю+У í e+ldю
, =1 AO,
^«ijkl Cijkl)
, =1 AO,
Cijkl (ekl)
AO
(Cjkl — Cijkl ]
N
У í e+ldю =
AO
N
У í e+ldю :
- AO,
where
= Cijkl (ekl) + (Cijkl Cijkl ) ( ekl},
1 N
(%) = — í e-ldю+ У í e+ldю
,=1 AO,
(23)
(24)
but only when there is no description of tensor fields is as in the Heterogeneous medium.
Now continue with the deduction of the polyphase averaged stress Upper scale mathematical model as within the using tools of hierarchical physics description.
At first, would apply the only notations of averaged strains, not of the formulation of these tensors through their own mathematical expressions using displacement vector u, one can have
1 1 N
(aa) =- f aVd+-V f a+dro =
\ 'J/ ao j J ao^ j V
= C
ijkl
AOk N
,= 1 AO,
It is relevant to mention here, that because Kushch and co-authors [9-15] mostly avoid writing of the Lower scale elastic equations (EE) and use this "singularity" assigned, artificial REVs - they artificially (for a purpose) derive formulae for and (a V) where
there are no surficial terms at all.
When averaged over the whole REV the stress tensor for polyphase medium that all the phases averaging expressions are combined
('Ekl)m + У ( e kl)q I + (<Cjkl Cijkl ) У ( e kl)q
,=1 У ,=1
N Л N
Cijkl (£kl)m + Cijkl У (£ W ), I + (Cjkl - Cijkl ) У W ), =
,=1 ) ,=1
= ^ (ek^m + Cm У > (25)
,=1
where each separate particle or macromolecular assembly (nanoparticle) stress tensor is
=aq J" ejld ю
(26)
here m is the subscript designating solid or soft solid matrix, liquid "matrix" or water solution medium volume all over the REV; N is the number of particles or macromolecular complexes, (ek;)q is the strain tensor
within the each q-th particle.
This is the usual formula we can see - the Homogeneous Elasticity Theory mathematical expressions (as in Kushch et al. [9-15], and other works) for the two-phase separately homogeneous medium.
To introduce the Lower scale physics of atomic, molecular interactions it needs to agree with the addition of this scale physics phenomena with its physical and mathematical scale models.
Next, when the hierarchical physics (HSP-VAT) applied to the two-phase particulate solid state problem, the formulae for averaged stress tensor ^a^ appeared as following
(aj) = 2Ck [v<u>m + (u)m)] +
+1VCk V<u>q +(v (u)q)
^ q=1 L
one can not write here (eH)q already, because the averaged (eH)q means and additional surficial terms
( , Y ]
+1C
ijkl
1 N
+1 У С
' ,= 1
—^ í udsm + —— í uds
— í uds, + —^ í uds, о J AO J
. (27)
It can be noticed that here there are the 2(N + 1) additional surficial terms - that is the correct averaging for Heterogeneous media.
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Separately in each phase the averaged stress tensor (g^
The following is the initial definition
(a,) = (c-em + 0№) = + (f ((emu^ + f ((e£) =
AO,
AQ„ AQp
if C™ and Cp are constants as in all Kushch' studies, for example, in [9-15], then
Cm cp
ijkl ' ' 4
Ao f fa)df (e£)d» = CL (ek^m + Cipki (eu)p.
AQm AQp
Now in each phase - in matrix (a,) is
\ ■> f m
(aij)m = iCiJklZk<)m = Cijkl (Zkl)m = Ci
while in the particulate phase (a^ is
(28)
V(u) + (V(u) )T +— f udsm + — f uds
AO ¿_ AO ¿_
(29)
(aij)p iC«klEki)p C4jkl {Ekl)p 2 C4jkl
v (u)p+(v (u)p ))j udspju dsp
AO
(30)
From this we can try to extract the effective stiffness
This expression has two additional last terms
coefficients Cm for Upper scale two-phase averaged comparing to usually assumed in the HCM. Even in this
simplification it is not equal to what homogeneous elasticity solution methods suggest, see in [13, 14] and references therein.
stress (a ^
Cjkl (£kl ) =
= i 2 v((( m + <u> p ) + ( u> m +V u) p )) T ,) =
this left part which is written as in Homogeneous mechanics right side we equalize to the HSP-VAT right part
2 C"k [(( u) m + V( u) m )T ]
(V (u) p +V (u) p):
+1 Cp
> . ' ah
1,
+—(Cm - Cp ) 2\ ijkl ijkl )
ijkl 1
AO.
f
f udsm + f uds,
AO
. (31)
When assuming or determined the constant tensor C*kl and ^e^ = 1 then we can write (following here [13] homogeneous treatment of heterogeneous problem) assigning the function for (a^ = C*kl with (e,^ = 1
Cjkl = 2 qu [(V (u) m + V( u) m )T T + (V ^ p +V< ^ p^
1 r — f 1 r —
- I u dsm + - I udsm . (32)
AO AO
Equilibrium elasticity equation (Elastostatics)
The equilibrium elasticity equation (Elastostatics) averaged over the two-phase composite material with the accepted ideal junction between phases all over the interface surface will be as following
(V-a,) = 0, (33)
(Va,} = V.(a,)m f (a, >*m +V^a,)p +
dSwm
+ ^kf (a, ^ =V^ a,)m +V'( a,)p +
dSwp
+ ¿0 f (a^m +¿0 f (a^p = V'(a,) = 0, (34)
+1 Cp T ~ ijkl
+ —
2
I (cm - cp )
Г. \ ijkl ijkl )
AO
we have an elimination of the two integral terms here -those are the traction terms on the interface surfaces dSwm, dSwp because of the perfect contact conditions on the interface, while those terms won't be eliminated for numerous practical problems,
-— f (a,-,-)dsm +—^ f (a,,)dsp = 0.
AO asf,^ ' AO v}
Again, it is happening because of equality of interface traction BC (but only if the cracks, if they exist,
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are having the equal tractions and normal vectors' nm and npi are collinear)
A7
as soon as
~~ Í («и )dSm —
Q Í (n m,'Vj )dSm — -aq Í ( '«j )dSp , (35)
— If — 1 r —
dsp; - Í udSm —--Í udSp. (Зб)
A7 J A7 J
dSm — 1
Further, we can create the Upper scale averaged equilibrium equation in its simplest form as Vaiy = 0,
which becomes after using the above derived averaged fields of stress via displacement fields in both phases as
or
— Cm V
, ^ ijklv
+ _ cp V
T Г. ijkl v
2 (CCijkl Cijkl )V'
V-(«,.) — 0 ^
V{ u m +(V( u) m ) ]
V (u) p +(V (u) p )
— Í u dSm + —^ Í u dS¡ ,o J до J
A7
A7
— 0. (37)
(V.«j> — V-j +V^«j)p Í («H)'dSm +
+ ("и )'dSp — 2 Cm>V[V(u)m +(V(^m ) ] +
V <u> p +(V (u) p )
+ _Cp V T ~ ijkl v
" 2 (ijkl Cijkl )V'
Í udSm + -— Í udS. A7 J A7 J
The last two (four actualy) terms are the surficial terms and as such present the tremendous interest for sold state mechanics as long as the physical effect at the interface in homogeneous elastic mechanics do not participate directly in the theory and in modeling. The boundary conditions are the boundary conditions, for the averaged upper scale physical and mathematical modeling even do not have them at all in homogeneous Continuum Mechanics.
The very important point in the derivation of hierarchical upper scale equations in solid state (soft solid state) is that in almost any heterogeneous medium the interface conditions are not perfect, and the material properties formed not only bulk each phase physics, but and in substantial part by the morphology of the polyphasing.
Taking this into account it is imperative to keep all terms in the modeling of upper scale elasticity equations, as for the stationary case in the following equation
J KK=(38)
dSwm dswp
In this equation which is the "bulk" averaged over the two phases Upper scale heterogeneous media elastostatic equation we can find even larger amount of interface physical effect terms - 4 surficial terms.
And these terms are the main difference and purpose to study, discover and use in heterogeneous polyphase media physical effects that are present, physicists know about most of them, but unattainable neither for physical and mathematical modeling nor for study and simulation via the conventional homogeneous physics tools and methods, as we saw this via numerous examples from a variety of sciences and technologies - http://travkin-hspt.com/compos/index.htm "Composite Engineering"; http://travkin-hspt.com/elastic/index.htm "Continuum Mechanics of Heterogeneous (Ht) Media; Elasticity, Plasticity"; http://travkin-hspt.com/eldyn/index.htm "Electrodynamics"; http://travkin-hspt.com/fluid/
index.htm "Fluid Mechanics"; http://travkin-hspt.com/ thermph/index.htm "Thermal Physics"; etc.
The history of mechanics, physical mechanics shows this struggle and search for solution for decades, if not for more than 100 years, since the discovery of the atomic structure of solid matters.
But the most interesting is the interplay of each phase effective coefficients Cj, Cj* for elasticity problem
(meanwhile, those are not the same as the phase coefficients, and even not equal to the homogeneous "effective" coefficients), bulk material effective stiffness coefficient as in this case C*H, and physical meaning
and input by the surficial interface physics terms in the governing equations for the upper scale as we have shown in the introduction to this paper, are vital for assessment and design, for example, for the conductivity, diffusivity and momentum problems.
It can be shown how using the same techniques that have been used for the phase upper scale averaged equations one can deduce and use the two-scale mathematical statements for the simulation and assessment of the steady-state two scale elasticity tasks.
Static elasticity of soft solid heterogeneous polyphase biomedia as cytoskeleton, cell, extracellular matrix (ECM), tissue, etc.
At present in biomechanics, biophysics application to medicine widely used by most of researchers the homogeneous theories that based on the concept of the homogeneous mixture for biomedia. We won't analyze and observe those approaches here in this paper. There are taken too many of assumptions and conjectures, see analysis in [2, 3, 4, 8]. We take, instead, the polyphase polyscale HSP-VAT approach in this field.
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It is known to continuum mechanics, biophysics researchers that any physical field's within continuum mechanics governing equations deduction has been started with application of the GO theorem to the piece, volume of a material, matter under investigation. We have been researched intensively on this subject in (http://www. travkin-hspt.com/elastic/whatsupf/whatsup.htm). The hard copy publication [1] summarizes shortly the problematic (simply wrong) physics and mathematics of homogeneous elasticity theory used for heterogeneous materials, media.
The matter is that the methods of HSP-VAT give the ability to model, simulate and make calculation practically of an exact nature, as long as we are able to figure out the morphology features, and we can do this at present in biology and medicine research.
When the polyphase HSP-VAT applied to the static elasticity problem for biomedia with fluid component (phase) (m) the equation for averaged over the Upper scale medium stress tensor
as
,) = Ck [V( V„ +(V< V„ )' ]-
+ 2 £1 |V<») q +((») J
2 q=1 L
where we can not write here the strain tensor ew as an averaged (e^ already over the phase(s) q or m,
because the averaged (e^ and means the
existence of additional surficial terms
+C
ijkl
1 N
+2 X ci
9=1
1 r — I 1 r —
- I V dsm + - I V dsm
AO¿m lAO¿m .
f udsq + —^ I udsc AOJ AO J
AO.
(39)
here we used only the deviatoric part t. of the stress tensor a. =[-pI + T. ] in the fluid phase where
^(VV + (VV)) = ^(2S .), where V is the velocity
T j =
while the
deformation tensor
is
S.. = I (VV + (VV )), and where Cmu (dynamic
viscosity) and CqkI are the stiffness tensors for phases q,
m is the subscript designating the liquid "matrix" or water solution (cytosol) medium volume all over the selected part within the biomedium, that is taken here for simplicity as the Newtonian fluid, while N is the number of macromolecular complexes (or organelles, etc.). To take into account the polyphase nature of cytosol there should be taken one more scale down physics model.
We have in all phase averaged equation here the 2(N + 1) additional surficial terms - that is, the correct averaging for Heterogeneous media brings in the substantially different from the homogeneous elasticity equations.
For further we need to turn to the static elasticity equation (as the simplest form elasticity mathematical equation) for the selected part (phase) within the biomedium
(V.a j) = 0,
(40)
as in a polyphase medium. The modeling elasticity phenomena for the heterogeneous part of a biomedium demand the elastodynamics governing equations, that has been developed also in the 90s. The Upper scale equilibrium averaged over the two-phase m and N = 1, p-phase where the perfect BC for a displacement at the interface has been applied (just as an example) to the biomedium, will be in its simplest form ^V«a^ = 0,
which becomes after using the above derived averaged fields of stress via the displacement field in soft solids and velocity field in a fluid phase as
|v<
v V m +(v( V
+|v
+- C k v
2 ijkl
v u> , +(v u> ,
i _l
ao.
+ _ cp V
T Г. ijkl v
—^ f Vdsm + —^ f Vds
AO3S„m lAO3Sj„m .
—— f u dsp + —^ f u ds AO J AO J
V
AO.
V(p) —— f pdsm = 0. X /m AO J
(41)
The above equation lacks of more tedious account for the fluid-(soft solid) displacement interaction at the dSwp interface surface on the upper scale description.
The phenomena of viscoelasticity that are truly pertained to the some part-subvolumes of interior of a biomedium like cell's skeleton, to the cell itself, to the cytoplasm as a whole for certain microorganisms and for locomotion, to the ECM, etc. must be accounted for by the two-scale, at least, models. The well studied and failed tasks in these fields are the viscoelastic properties of blood polyphase fluid, blood flow, other biomedia models, that are also the subject for scaled, polyphase, polyphysics concepts, modeling which should be followed by the scaled simulation. The basic concepts and viscoelastic, viscoplastic governing equations for heterogeneous media via HSP-VAT also have been developed in the 90s.
Elastodynamics - the wave equations in heterogeneous solid state media
We would start with the homogeneous media transient elasticity equation which reads as
S
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т, d2u
(42)
= Р
dt2
Р —
m dt
AO.
|£ (Um ))!■=
dt
d2 (u,).
+р p-gt^-рp
dt
AL J ((u' Ж
AO
Ц (up ))}*p; [Nm3 ], (43)
- Qi Vi
+1 cp V
2 ((и CjM )Vi
^u)m +(V ^m ) ] V( ^ p +(( ^ p ))
—^ í udsm + -— í uds,
AO J AO J
JLj(a ^ +AQj(a j)idsp + (Г) m + (F) p
dSwm dSwp
= (Р Р)Э2 (u"I
= (Pm -Р p Ьд?
(pm -Рp
where F - is the body force per unit volume [(N/(m3))].
Averaged over the REV for the upper scale presentation using the developed HSP-VAT methods for appropriate operators having place in the homogeneous equation brings this equation to the form
<V-.) + <F> = f|2
(V-"s>+<F)=V-("S),J (>>s-+
dSwm
aJ (j ^ + =
= V °j)m +V'( °j)P ^ J K ^ +
dSwm
M (:>*'+<F>=(■£)=
J ( K^
AO J ((u - »ids-
^ j( v. (f (u-
(44)
this equation is valid only if the BC for displacement fields on the interface dSwm are as following
dSm = -dsp ; Um = up , but nm *CTLswm * nP ^L, '
In this equation which is the Upper scale averaged over the two phases elastodynamics equation we can find even bigger amount of interface physical effect terms - 6 surficial terms.
Especially troublesome the upper scale EE will be when the imperfect BC of displacements u |3S * u |3S
and traction vectors nmaL * n a satisfied (that is
m lss„m P |3S„p
the practical problems of usual outcome), in this equation we can find even bigger amount of interface physical effect terms - 10 surficial terms with the different displacement vector field u and stress tensor fields (g j) should be enforced as in the following
- cm ,Vi 2
ijkl
+-CL V
where Vsq is the speed of displacement of q-th phase
N
interface surface, ^ ((Swq) = dSwm in this equation for
q=1
matrix and particulate phase elasticity.
( N \
Combining all these ( )m + X ( ) | separate terms V m q=1 q J averaged mathematics we got for the two-phase m and p (q = 1) the averaged equation
+2(Ck )V
V(u)m +(V {u)- )
V u> p +(V (u) p))
—^ í udsm + í udsm
AO J AO J
ijkl
AO.
—^ í uds„ + —^ í uds AO J AO J
/
Y
_L J (aj)idsm +_L J (Gj )idsp + +
dSwm dSwp
d2 (u) , чд2(u)
= (р +(р -
KVm) VpJ д о
-(Р- )
dt
-(рp)dt
AO í (Vsq (um ))idsm
AO/(Vs. (- p ^'p
v. (dt (u-»f.
3S„
;[v, (u p
3S„
(45)
Completely different amount of possibilities and the new physical effects right now is presented (after 15-16 years of waiting period) for researchers in HtCM.
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д
р
Two-scale elasticity in 3D, 2D and 1D with isotropic/anisotropic homogeneous/inhomogeneous lower scale medium
In the 2D or 3D Lower (2DL, 3DL) scale physical and mathematical statements the Hierarchical Upper scale elasticity equations for heterogeneous polyphase media can be, for example, of a 2DL1DU (1DU Upper) (Fig. 3) statement which is easier to assess and simulate.
Рис. 3. Схематическая модель двухфазной слоистой среды типа 2DL1DU (2ДН1ДВ - 2-размерная нижняя среда переходит в 1-размерную среду верхнего масштаба) под приложенной силой Fig. 3. Schematic model of the two-phase layered medium of the type 2DL1DU under the force applied
The 1DL1DU elastodynamics statements with the lower scale homogeneous isotropic medium (might be the layered one) the upper scale elasticity equation in the phase one (p = 1)
This equation formulates as
(( ». > ^aU « z >*
+ - J, -
AQj Uz
:(y, Z > I dsi =
= Pl
d2 Wi
dt2
Э
pi dt
AsJ ( («i >>
A^Vi (Afc >]).,; [N/m3 ], (46)
Meanwhile, the left part mathematical operators of these equations have been studied thoroughly for the globular morphologies two-phase media by Travkin, V.S. and V.Kushch in 1994-96, with results that mostly are unpublished.
Then the same left part upper scale equation was solved for the layered morphology via numerical half-analytical for inhomogeneous lower scale media and in analytical form for homogeneous lower scale both phase formulations. Some excerpts from this solution are given also only in the internet in - "When the 2x2 is not going to be 4 - What to do?" http://www.travkin-hspt.com/eldyn/WhatToDo2.htm.
The two-scale statement we introduce here in the next sub-section is updated for the temperature fields in the two-phase solid state composite, although it is completely suited and for steady-state other diffusivity transport phenomena, as a dielectric media composite with electric field distribution, diffusion and/or displacement fields in a solid state two-phase globular medium, etc.
Example of solution for the two-scale 3DL1DU HSP-VAT diffusive governing equations
An infinite homogeneous and of inhomogeneous morphologies media containing a three-dimensional (3D) arrays of spherical particles are chosen for analysis as the globular morphology samples as for the two-scale solution and data reduction and analysis.
In this problem was considered a two-phase solid heterogeneous medium consisting of an isotropic continuous (solid or fluid) matrix and an isotropic discontinuous phase (spherical particles or pore spherical cavities). The volume fraction of matrix, or 1st phase, is <mi>= A^/AO, the volume fraction of filler, or 2nd phase, is <m2> = 1 - <m{> = AO2/AO, where AO = AOi + AO2 is the volume of the REV. The constant properties (phase thermal conductivities, k1 and k2), stationary (time-independent) temperature field differential equations for T1 and T2, the local (lower scale) phase temperature variables are determined through the 3D equations, for the matrix phase in Cartesian coordinates
k
д2т э2т э2т
Эх2 Эу2 dz
= 0,
(47)
and for the globular phase temperature in spherical coordinates for each particle
where C1 is the stiffness coefficient in the phase 1 (also might be the matrix phase).
The simplified version of these two-phase equations with the neglected movement of the interface surface dSw1 (Vs1 = 0) was solved as one of the acoustic equations on the upper scale of layered medium at the beginning of 2000s and some results were published only in the web in -"Two Scale Solution for Acoustic Wave Propagation Through the Multilayer Two-Phase Medium" http://www.travkin-hspt.com/acoustics/ supercross.htm.
fa 2
d2T
2ijk
i Э72
2ijk
i
д2Т I
u 2ijk
dr2
r dr r2 sin2 6 Эф2
_L dT
r2 Э62
2ijk + Ctg 6 dT2jk
I
Э6
= 0,
(48)
where indexes ijk designate the specific spherical particle, with the conjugate IV-th kind of interfacial (1-2) temperature boundary conditions between the homogeneous phases
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т( 4s12 = T2( С12;
к
dT1 ( х )
dn
= k
dT2 (x)
3S12
dn
(49)
(50)
3S12
Рис. 4. Модель двухфазной среды с неоднородной объемной фракцией фазы частиц (и второй непрерывной
фазы). Температурный поток направлен снизу вверх Fig. 4. Model of the two-phase medium with variable volume fraction of particulate phase. Temperature flux is applied from the bottom
When the particles have the same diameters, the result is the triple periodic structure used widely, beginning from Rayleigh's work, to evaluate the effective properties of particulate composites. We have been using that morphology for many HSP-VAT purposes as well.
For this problem the upper scale averaged diffusive equations will be for each phase
V(> V{t1}1 )+V.
No internal sources (including surficial sources) are present inside the composite medium, so that the temperature field is determined by the boundary conditions at the external surfaces of the sample's medium and by the boundary conditions at the interface surface. After correct formulation of these conditions, the problem is completely stated and has a unique solution on the lower scale. It also has the unique solution on the upper scale for the VAT upper scale equations, as long as we have solved the first scale problem. We assume here the Bottom-Up sequence of scales.
The particles are arranged so that their centers lie at the nodes of a simple cubic lattice with period a. The field in this heterogeneous medium is caused by a constant temperature flux q0 prescribed at the sample boundaries, which, due to the absence of internal sources, leads to the equality of averaged internal temperature flux field <q> = q0 (the sample boundary surface dSo was chosen to cut only through the matrix phase, Fig. 4).
— J T1 ds +—O J Vt= 0,
9Sj2 9S,2
(51)
or in a 1DU (Upper) scale notations
dz"
{m)
d {T }
dz"
dz"
—^ f T\ds\ AO i
t — f VT'ds'1 = 0, AO j 1
(52)
for the 2nd phase equation is
V'((m2) V{T2 }2 )+V.
—^ f T 2 ds 2
AO j
or in a 1DU statement as
— f VT 'ds2 = 0, AO J 2
(5З)
dz"
Ы
dz"
dz"
f T 2 ds 2 AO ¿
1 t —
t- I VT «ds2 = 0.
AO Л 2
(54)
The exact solution of the globular morphology two-scale diffusive problem above (47)-(54) was obtained for the first time in 1994-96 with the accuracy unsurpassed up to these days. This accuracy is based on the analytical nature of the lower scale problems' solution.
A few excerpts from this solution have been published in papers, for example in [27], while the more detailed way of treatment of this problem was published in the internet in - "Globular Morphology Two Scale Electrostatic Exact Solutions" http://www.travkin-hspt.com/eldyn/glob1.htm.
Meanwhile, it should be stressed out that the full range of specifics for the statement, mathematical analytical methods for the two-scale conduct, the solution algorithms, and the two-scale results and comparisons have not been published yet. Nevertheless, there were obtained knowledge of many outstanding problem's and the theory features for the globular morphology and inhomogeneous fields at both scale physics statements.
As long as this kind of morphology is often being used in physics and mathematics for ground verification of solutions, coefficients comparison, test purposes, we should state that the solutions obtained in the 90s can be applicable as the partial consideration of the solid heterogeneous medium elasticity two-scale problem solution for globular morphologies.
2
2
12
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Conclusions
We have shown in this paper for the first time the obtained in 1994-95 short, but rather full path to derivation of the two-scale (local-nonlocal) mathematical formulation for the elasticity in the heterogeneous, polyphase solid state composite media.
Obtained the two-scale models are much more complex than the homogeneous one scale media elasticity mathematical models and their statements. Nonetheless, they are simply correct for Heterogeneous media, more physically descriptive and useful as it is shown during the last ~25 years in other physical disciplines such as fluid mechanics, thermal physics, acoustics, electrodynamics, heterogeneous mathematics, atomic scale physics, nuclear physics, and their numerous applications in engineering sciences, biological sciences, technologies.
Here it is presented as the two-scale, at least, models interconnected narrative (can be more scales included, albeit and more complicated physics and math with), where the Lower scale models are of familiar from the major physical textbooks description with the homogeneous fields that are formulated as homogeneous mathematical statements. Meanwhile, the upper second scale modeling formulation for the elasticity physical processes mentioned above have been developed for many years already, used for studies, obtained the results unattainable with the one scale homogeneous physics.
Now the tools and methods of HSP-VAT are available in the area of elasticity in heterogeneous and scaled media as solid state and soft solid matter, biomedia.
Acknowledgements
We would like to sincerely express our acknowledgment to T.Champion and E.G.Travkina mother of V.S.T. for their help and encouragement in providing this work.
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