# INTRODUCTION

Urgency of a theme of research. Degree of its readiness. Now the world building sector passes through the process of serious transformation connected with refusal of traditional methods of designing and building.

Growing complexity and an information saturation of building projects have led to gradual universal transition to technologies of information modelling of buildings and constructions, so-called BIM-technologies, and became the answer to necessity of gathering, the account and processing in the course of designing, building and operation of objects of capital construction of considerable volumes of the information and their subsequent updating in the course of project realisation. Development of information technologies and occurrence of purpose-built software products have allowed to create digital information models of building objects which represent databases with strictly systematised information on all parts of the project.Now in the Russian Federation development and introduction BIM - technologies in a building sector it is recognised at the state level. In this connection in 2014 by results of session of presidium of Council at the president of the Russian Federation on modernisation of economy and innovative development of Russia Minstroju of Russia, Rosstandartu, etc. it was entrusted to develop and confirm the plan of stage-by-stage introduction of technologies BIM in the field of industrial and a constructional engineering. Thus in December, 2014 the Plan of introduction of BIM-technologies has been confirmed by the Ministry of building and zhilishchnoyokommunalnogo economy of the Russian Federation (the Order ³926/pr from 29.12.2014, and then the order ³151/pr from 04.03.2015 had been confirmed Plan updatings). According to the offered Plan of introduction of BIM-technologies, on July, 19th, 2018 the president of the Russian Federation V.V. Putin signs the commission to the government of the Russian Federation (Pr - 1235 from 19.07.2018) about preparation of experts in sphere information

Modelling in building and stimulation of working out and use of the domestic software for information modelling of buildings and constructions. Thus, considering importance of BIM-technologies in a building sector there is a possibility of introduction of results of dissertational research in databases of the corresponding software products used at construction of information models of buildings and constructions.

Perfection of methods of a structural calculations and technologies of reception of various materials have led to that there was possible a manufacturing of designs which at the expense of projected variable geometrical characteristics, would be as much as possible easy, possessed low heat conductivity, and the maximum indicators of durability. Such designs allow to give to buildings interesting, and in some cases unique, architectonic expressiveness, and translates them in the category of the unique. For the decision of these questions the most perspective materials are the materials which mechanical characteristics change along spatial co-ordinates, and designs made of such materials are called as non-uniform. Therefore there is an interest to an estimation of tensely - state of strain of designs executed of such materials.

In mechanics of non-uniform designs there is a following grading of the basic types neodnorodnostej: continuous, kusochno - homogeneous and stochastic, each of which grows out of impact of various factors.

These factors can be straight and indirect. Indirect factors concern: manufacturing techniques of designs, operational impacts, and also natural heterogeneity. Such processing method which hardening is called concerns straight methods of creation of heterogeneity in designs.The account of heterogeneity of structure of a material and its physicomechanical properties is one of perspective directions at calculation of building designs. Designing of the designs allowing effectively

To use prochnostnye possibilities of materials, and methods of their calculation will allow to receive economic benefit at the expense of reduction of a thickness of a non-uniform design (decrease in a constant load at the expense of reduction of a body weight and the material expense).

In engineering practice the designs working on a bending down - thin-wall spatial designs of a type of flat envelopments and plates, and also rod designs of a type of girders are widely used. It is known, that in the designs working on a bending down, a material it is used irrationally. The basic loading is born by extreme layers of a material, and the material in the field of an average part of a design is used not to the extent of the prochnostnyh possibilities. If by means of certain processing methods to create in top and base layers of a design of a working area of heterogeneity in which the material possesses the raised mechanical properties it is possible to raise efficiency of use of a material.

Recently there were many sorts of new perspective materials. In various branches of technics are widely applied dispersno - and is discrete-non-uniform designs with layers from easy effective fillers, kleenye wooden, derevometallicheskie designs, deltayodrevesina, LVL-wood, composites on polymeric, carbon, metal and organic bases. The designs executed from such materials, can have cost and materialoemkost on 35-50 % smaller in comparison with traditional homogeneous designs.

In engineering practice various sorts of cellular materials find application. They possess a number of advantages: lungs, rigid, effectively absorb noise, possess low heat conductivity, high energopogloshchajushchej ability at a plastic warping, low heat conductivity and elektroprovodnostju, a high weight strength, small mass etc. the Most perspective cellular materials now are foam concrete, a porous concrete, penoaljuminy, penozhelezo and penostal they find wide application in building. However all number

Positive properties of such materials allows to use them in designs only in a restrained range of operating loadings because the designs executed from such materials, have low prochnostnye characteristics. Therefore for increase prochnostnyh characteristics and increase in efficiency of use of a material of such designs, it is necessary to strengthen their surface layers that is the occurrence reason in a material of a design of technological heterogeneity with in advance set properties.

In practice wide application is found by various processing methods of hardening of surface layers of structural components (for example, nauglerozhivanie, processing of a surface by pressure, etc.). At manufacturing of designs from concrete layers from concrete of various structures or polimerbetonov with the various maintenance of polymers can be created.

In this connection there is a necessity for working out of mathematical models and methods of calculation of the non-uniform designs allowing effectively to use prochnostnye possibility of materials and to investigate influence of parametres of heterogeneity on distribution of internal pressure that will allow to receive economic benefit at the expense of reduction of a body weight of non-uniform designs.

Studying of physical laws and the processes proceeding in non-uniform designs, the section of mechanics of a deformable solid body which the mechanics of non-uniform bodies is called is engaged. If the classical mechanics totals more than centenary history, since G.Galileja, R.Guka, J.Bernulli, L.Nave's works and others the mechanics of non-uniform bodies has less than century history. The first works in this direction have been published in the mid-thirties Of this year Mihlinym and devoted a conclusion of the equations of the theory of elasticity of a non-uniform body. However due development of the artificer of non-uniform bodies has received only in 1950th years, that directly it has been connected with COMPUTER creation. Development of mechanics of non-uniform bodies is connected with works of such scientists as F.S.Yassinsky [96] V.P.Plevako, N.A.

Rostovtsev, D.I.Sherman, A.T.Vasilenko, J.M.Grigorenko, I.I.Goldenblat, V.A.Gordon, A.D.Kolchin [45], V.A.Lomakin [62], V.V. Petrov [82], V.I.Andreev [15, 16], V.Olshak [70] and many other things.

Questions of loss of stability of the compressed rods executed of materials strengthened by repeated mehaniko-thermal processing were considered L.V.Kuksy and V.I.Klimenko's works [54, 55, 56].

In researches of gears of structurization intermetallidov, their additional hardening, behaviour on-loading and research of their physicomechanical properties were engaged L.M.Gurevich, S.P.Pisarev, R.E.Novikov, J.P.Trykov, V.N.Arisova, A.I.Kovtun, T.V.Chermashentseva, S.V.Mjamin [98, 33, 8, 34, 71, 75, 76].

The new class of the non-uniform structural materials made of multilayered composit workpieces, is investigated in A.I.bad's works [87].

In E.A.Gridasovoj, O.N.Ljubimovoj, V.K.Goncharuka, A.A.Bocharovoj, A.A.Ratnikova and N.J.Golobokovoj's works [22, 29, 30] results of creation of rods from non-uniform structural materials on a thickness are resulted. Also in works [22, 29, 30] are resulted prochnostnye trials of these rods and their physicomechanical characteristics.

Researches on hardening of surface layers of plaster and cement samples by solutions from secondary polystyrene and their research prochnostnyh characteristics were engaged in N.N.Fomina, M.M.Poljansky, S.A.Pimenov [104].

Research physicomechanical and energopogloshchajushchih properties of cellular materials, and also mathematical modelling of their behaviour on-loading was widely shined in S.V.Komarova, A.I.Ivashkina's [46] works, D.O.Butarovicha, A.A.Smirnova, D.M.Ryabov [22, 23], V.S.Bondarja, J.M.Temisa, M.V.Birjukovoj [19, 20, 21], V.A.Markova, A.F.Ovchinnikova [63], A.P.Gusarova, A.V.Zharikov [64]. Also A.M.Avdeenko, JU.A.Krupin and N.A.

Pimenova [10-12] in the works investigated the processes occurring at destruction of cellular materials.

Researches on working out of the private mathematical models describing work of non-uniform designs were engaged in A.M.Avdeenko [10], S.M.Shljahov and its pupils [107-108, 67], J.V.Puharenko [90].

Among the foreign researchers studying questions of mechanics of non-uniform bodies it is necessary to allocate such scientists as G.R. Johnson, W.H. Cook [5], T.J. Holmquist [4], V.S. Deshpande, N.A. Fleck [3], C.N. Kingery, G. Bulmash [6], G. Randers-Pehrson [7], A. Reyes [1], P.H. Thornton, C.L. Magee [8], M.M. Carroll, A.C. Holt [2], A.L. Garson V. Tvergaard [9].

Calculation of non-uniform designs represents a challenge connected with the decision of the nonlinear differential equations. Results of the analysis of a wide number of references have shown, that works in this direction in Russia and is abroad published it is not enough. Practically there are no works on research of the is intense-deformed condition of non-uniform physically nonlinear thin-wall spatial designs of a variable thickness of a type of flat envelopments and plates, and also rod designs of a type of girders.

Thus, the urgency of a theme of dissertational research, proves to be true that in engineering practice at the expense of the directed designing of heterogeneity and variable geometrical characteristics it is possible to optimise designs, however it is complicated now by insufficiency of researches, absence of a general mathematical model and a design procedure. In the project of the plan of fundamental scientific researches RAASN and Minstroja the Russian Federation for 2020-2030 is planned: «.... Working out fizikoyomehanicheskih models of a warping of new building materials and designs taking into account physical nonlinearity, constructive and got anisotropy and heterogeneity» and «. Working out and development of methods of calculation of new designs, buildings and constructions taking into account physical and geometrical nonlinearity and heterogeneity».

Object and object of research. Object of research in dissertational work are non-uniform physically nonlinear thin-wall designs of a variable thickness of a type of flat envelopments and plates, and also rod designs of a type of girders.

Object of research is influence of heterogeneity of a material and a variable thickness on tensely-state of strain thin-wall spatial designs executed of a nelinejno-deformed material.

The purpose of dissertational work is working out of a design procedure of non-uniform physically nonlinear thin-wall spatial designs of a variable thickness. According to the work purpose following problems are formulated:

1. To analyse and ordering of experimental data and results of scientific researches on non-uniform materials, methods of creation of heterogeneity and ways of the mathematical description of behaviour of non-uniform designs;

2. On the basis of the phenomenological approach to construct functions of heterogeneity in the form of corresponding analytical expressions;

3. To improve inkrementalnuju the mathematical model applied to calculation of non-uniform physically nonlinear thin-wall spatial designs of a variable thickness;

4. To investigate features of application of a method of the quickest descent for the decision of physically nonlinear problems;

5. To develop algorithm of calculation and to prepare on its basis the software, to make its updating and to execute calculation of non-uniform physically nonlinear thin-wall spatial designs of a variable thickness at various combinations of initial data;

6. On the basis of the received results of calculation to execute an estimation of the is intense-deformed condition of considered designs, and

Also to make the analysis of the effects caused in a design by presence of physical nonlinearity and heterogeneity of a material and a variable thickness.

Scientific novelty of dissertational work:

1. On the basis of the phenomenological approach new analytical dependences of functions of the heterogeneity, describing change prochnostnyh material characteristics in a non-uniform layer on a thickness of a design have been received;

2. The algorithm of application of a method of the quickest descent for the decision of physically nonlinear problems is investigated. The way of construction of initial approach is offered and approved;

3. The estimation of the is intense-deformed condition of some designs on which basis the analysis of effects caused by presence of physical nonlinearity and heterogeneity of a material and a variable thickness is made is executed, and is shown, that presence of layers of heterogeneity on a thickness of a design from physically nonlinear material and a variable thickness leads to essential redistribution of internal pressure on a thickness of a design, at its bending down, under the influence of a lateral load;

4. It is established that technological heterogeneity can be considered as the additional tool of the designer for management of the is intense-deformed condition of a design with a view of increase of its optimality;

5. Numerical experiments have allowed to investigate influence of heterogeneity of a material on a thickness of a design and a variable thickness on intense-state of strain designs executed of physically nonlinear material. Presence of layers of heterogeneity on a thickness of physically nonlinear designs and a variable thickness is revealed, that, gives the chance the directed regulation of a stress condition of a design.

Practical value and realisation of the received results:

1. The software is developed for realisation of a method of the quickest descent, allowing to solve various problems of a bending down of non-uniform physically nonlinear flat envelopments, plates and girders of a constant and a variable thickness;

2. The offered technique and algorithm of calculation allow to define the is intense-deformed condition of flat envelopments, plates and the girders of a variable thickness executed from the nelinejno-deformed non-uniform material;

3. In work influence of parametres of technological heterogeneity and a variable thickness on intense-state of strain of some designs is investigated, and possibility of regulation of the is intense-deformed condition of physically nonlinear designs is proved;

4. Results of dissertational researches can be used the scientific organisations and project institutes at designing and a structural calculations of coatings and floorings of unique and wide-span buildings and constructions;

5. Introduction of results of dissertational researches in databases of software products for a structural engineering on the basis of BIM-technologies will allow to expand possibilities of engineers-designers and to deduce results of their work on new level.

Degree of reliability of results of dissertational work is provided with a correctness of an applied mathematical model, severity of a used mathematical apparatus, and also literacy of the made algorithm of calculation and presence of carefully debugged software that proves to be true quantitative and qualitative conformity of the results received in work, on the offered mathematical model, with results of decisions of other authors presented in a number of works.

Dissertational work consists of the introduction, four heads, the conclusion, the list of used sources and the appendix.

In chapter 1 of dissertational work the review of a condition of a question on investigated subjects which consists of two parts is resulted: the review of researches of non-uniform designs with changing on a thickness prochnostnymi characteristics and mathematical models of calculation. In the first part the expediency of use of non-uniform materials, grading of non-uniform materials on ways of creation of heterogeneity is stated, and also results of experimental and numerical researches of physicomechanical properties of non-uniform materials and an estimation of their behaviour on-loading are resulted. In the second part private models of calculation of non-uniform designs existing at present, and also ways of the mathematical description of those or other physicomechanical characteristics of non-uniform materials received on the basis of the analysis and ordering of existing experimental data are analyzed.

The second chapter of dissertational work is devoted a conclusion inkrementalnyh the differential equations of a bending down of non-uniform physically nonlinear flat envelopments, plates and girders of a variable thickness which are under the influence of a lateral load. For the account of heterogeneity of a material properties on a thickness of designs the concept of front of heterogeneity is used. On the basis of the phenomenological approach, within heterogeneity front function of heterogeneity which describes change of time resistance of a material on a thickness of a non-uniform layer is entered. At construction inkrementalnoj a mathematical model as a basis, the theory small uprugoplasticheskih A.A.Ilyushin's deformations is used. Introduction of function of heterogeneity in inkrementalnye physical parities is carried out through communication between an increment tenzora-deviatora pressure and an increment tenzora-deviatora deformations. On the basis of this approach and set of the used hypotheses have been received inkrementalnye the equations of a bending down of non-uniform physically nonlinear flat envelopments, plates and girders of a variable thickness.

The technique of the decision of these equations by a method of the quickest descent with use of a method of final differences is resulted.

In the third chapter of dissertational work results of numerical experiments are analyzed. For an estimation of influence of heterogeneity of a material properties on intense-state of strain, as an example, results of the decision of specific targets of a bending down of flat envelopments, plates and the girders of a constant thickness executed from nelinejno - a deformable material are analyzed. Problems of a bending down of flat envelopments, plates and girders are considered at two-sided and at single-sided heterogeneity on a thickness. Influence of the factor of heterogeneity on intense - a state of strain of physically nonlinear designs is studied.

In the fourth chapter of the dissertation results of numerical experiments on which base the estimation of influence of a variable thickness on intense-state of strain of some designs is spent are analyzed. As an example, results of the decision of specific targets of a bending down of physically nonlinear flat envelopments, plates and girders of a variable thickness are analyzed. Influence of a variable thickness on intense - a state of strain of physically nonlinear designs is studied.

Received in the third and fourth chapter results of numerical experiments have allowed to study influence of change of some parametres inkrementalnoj a mathematical model on tensely-state of strain flat envelopments, plates and girders at various combinations of the initial given and boundary conditions.

In the conclusion of dissertational work general conclusions by the received results are formulated.

In the appendix to work the developed conclusions of the equations and boundary conditions with use of a method of final differences, inquiries and adoption deeds of materials of dissertational work in educational process and industrial activity, and also certificates on the state registration of the computer programs are resulted. All calculations were carried out with use

The program complexes made by the author, in programming language VBA Excel 2013 (Visual Basic for Applications Excel 2013).

The theoretical importance of work.

1. The analysis and ordering of experimental data and results of scientific researches on non-uniform materials, methods of creation of heterogeneity and ways of the mathematical description of behaviour of non-uniform designs is made;

2. On the basis of the phenomenological approach new analytical dependences of functions of the heterogeneity, describing change prochnostnyh material characteristics in a non-uniform layer on a thickness of a design are received;

3. The mathematical model applied to calculation of non-uniform physically nonlinear thin-wall spatial designs of a variable thickness is improved inkrementalnaja;

4. The algorithm of application of a method of the quickest descent for the decision of physically nonlinear problems is investigated. The way of construction of initial approach is offered and approved.

The practical importance of work. On the basis of results of dissertational researches the technique and the software is developed for definition of parametres of the is intense-deformed condition of non-uniform physically nonlinear thin-wall spatial designs of a variable thickness. These program complexes can be used at designing and a structural calculations of coatings and floorings of unique and wide-span buildings and constructions. Therefore set of results of researches, techniques and maintenance will allow experts-raschetchikam to raise level of validity of the decisions and to lower risk of occurrence of extreme situations.

Methodology and research methods. In dissertational work the known and approved theories by definition of the is intense-deformed condition non-uniform physically nonlinear were used

Flat envelopments, plates and girders of a variable thickness. For definition of parametres of the is intense-deformed condition of these designs following methods were used: a two-step-by-step method of consecutive dither of parametres (DMPVP) V.V. Petrov, a method of the quickest descent (Ministry of Taxes and Tax Collection), a method of final differences (MKR).

Approbation of results. Substantive provisions and results of dissertational researches were reported at following conferences: interuniversity scientific and technical conference «Problems of durability of elements of designs under the influence of loadings and working environments» SGTU Gagarina J.A.'s name (Saratov, 2014), XVI th and XVII th international nauchnoyotehnicheskoj conferences «Actual problems of building, the building industry and the industry» TulGu (Tula, 2015, 2016), II th

The international scientifically-practical conference «Increase of reliability and safety of transport constructions and communications» SGTU Gagarina J.A.'s name (Saratov, 2016), the international scientifically-practical conference of "Concept" of the Society of knowledge »in a modern science» (Perm, 2018).

Results of dissertational work are introduced in a speciality training course «Building of unique buildings and constructions» on disciplines «Nonlinear problems of building mechanics» and «the Theory and calculation of plates and envelopments» and in a number of training courses poslevuzovskogo formations. Developed program complexes and results of researches are accepted to introduction at Joint-Stock Company "ТЕПЛОГАЗИНЖИНИРИНГ" enterprise.

Publications. On a dissertation theme 22 printing works (from them 5 - in the editions recommended by List VAK the Russian Federation, one of them enters into database Russian Science Citation Index (RSCI) on platform Web of Science (WoS), 7 - in collections of proceedings, 3 articles in materials of conferences, 7 articles included in database RINTS), 2 patents are published.

The positions which are taken out on protection:

1. Inkrementalnaja a mathematical model of calculation of non-uniform physically nonlinear thin-wall spatial designs of a variable thickness;

2. Analytical dependences for the heterogeneity function, describing change prochnostnyh material characteristics in a non-uniform layer on a thickness of a design;

3. A technique of definition of parametres of the is intense-deformed condition of flat envelopments, plates and the girders of a variable thickness executed from the nelinejno-deformed non-uniform material with use of a method of the quickest descent. Algorithm of construction of initial approach;

4. Results of numerical experiments on influence of parametres of heterogeneity of a material and a variable thickness on intense - a state of strain of flat envelopments, plates and the girders executed from the nelinejno-deformed material.

Structure and volume of dissertational work. Dissertational work consists of the title page, a table of contents, the introduction, four heads, the conclusion, the list of the literature, the appendix. The volume of dissertational work makes 150 pages of the typewritten text, the list of the literature of 108 names on 12 pages and appendices on 25 pages. The work total amount makes 187 pages.

## More on topic INTRODUCTION:

- in introduction
- INTRODUCTION
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- INTRODUCTION
- approbation and introduction of results.
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- Introduction
- INTRODUCTION
- INTRODUCTION
- Introduction
- Introduction
- INTRODUCTION
- Instead of Introduction …
- PRACTICAL INTRODUCTION OF RESULTS OF WORK
- 5. Attention strengthening to questions of legal introduction.
- Introduction
- Introduction
- Introduction