bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Quality Improvement by Additional Filtering through Sorption Loading Modified by Fullerenes
Authors: Kim Arkady , Chernikov Nikolai
Published: January 2015

The actual problem of necessity of additional water processing for the consumer’s drinking purposes is considered. It is connected with water passing through the city pipes the condition of which is unsatisfactory, repeatedly become soiled by physical, chemical, and bacteriological components; it is also promoted by greater duration of stay of water in the water delivery system. The technique of modifying activated coals by fullerenes is presented. The technique of research of the initial and modified birch and coconut drawn up coals is developed by filtering. Permanganate demand, chromaticity, the content of ferrum in the initial and treated water is chosen as controllable parameters. Results of comparative laboratory researches of the initial and modified activated coal as a result of additional water processing are demonstrated. An original technique of regeneration of the used activated coals with application of sodium hypochlorite is developed. Bactericidal properties of the activated coal modified by fullerenes are confirmed. Dependences of duration of filter runs and efficiency of additional water treatment in filters with birch activated coal modified by fullerenes are obtained.
Thermal Comfort and Energy Performance Assessment for Residential Building in Temperate Continental Climate
Authors: Korniyenko Sergey
Published: January 2015

The increase of thermal comfort and energy performance of buildings is an actual problem of modern architecture and construction. The paper based on field study gives the assessment of thermal comfort and energy performance for multifamily residential building in temperate continental climate. The program of the field study included the measurements of microclimate parameters in rooms of various apartments (first stage) and of the thermal performance of building envelope elements (second stage). The results of the field study showed that the thermal comfort and thermal performance of building envelope elements were not provided. The deterioration of thermal comfort and thermal performance of the building can be caused by numerous defects allowed in the course of construction. Thermal modernization of the building is necessary for the purpose of elimination of the specified defects and increase of energy performance.
Fire Safeguards of “Plastbau” Construction
Authors: Kostić Radinko , Vatin Nikolay , Murgul Vera
Published: January 2015

There are exposed the results of resistance testing on effects of fire in interfloor construction and wall panel made according to “plastbau” system technology out of expandable polystyrene, when they are protected by mortar extension as an insulator. The applied testing method is prescribed by standard form EN 13501-2. Based on testing results, there is affirmed that interfloor construction fulfills resistance criteria on effects of fire of 180 min, and wall panel fulfills resistance criteria on effects of fire of 60 min, when it is protected by mortar extension as an insulator..
The Influence of the Thermal-Insulating Properties of External Enclosure Structures on the Energy and Opportunity Costs
Authors: Vatin Nikolai , Tarasova Darya , Nemova Darya
Published: January 2015

In this article three translucent structures with various level of thermal shielding were considered. The analysis of influence of thermal shielding level of the external enclosure structures on energy and opportunity costs is provided in this article. The payback period of translucent structures due to thermal energy saving is defined.
Energy-Efficient Multi-Comfort Group of Buildings in Svetlorechenskiy Estate
Authors: Perminov Roman , Maltseva Irina , Kaganovich Natalia , Yolohov Alexander
Published: January 2015

Construction of energy-efficient and passive houses spreading across the world with remarkable rate due to their almost incontestable advantages. Yet such construction remain challenging in regions with harsh climate. This article provides an example of complex approach to building multi-comfort houses using modern technology and rational design.
Results of Multi Comfort Building Designing
Authors: Bazhenova Ekaterina , Bykova Julia , Bryus Daria , Tseytin Dmitriy
Published: January 2015

This article is dedicated to the project of elementary school building in Gaziantep, Turkey. Particular interest in the construction of energy-effective buildings, appeared in last years, stipulate relevance and importance of this work. The main of the article is to describe the project and to estimate it from the point of energy-efficiency.Architectural and constructional decisions were also substantiated in the work and special attention was put on the possibility of reaching target values of energy-efficiency criteria by using different ways of energy consumption reduction.As the conclusion, it could be said that the building belongs to the highest class of energy-efficiency.
Increasing the Wind Turbine Power Using Aerodynamics Shape of the Building
Authors: Krivoy Sergey Aleksandrovich , Bolshakov Nikolay Sergeevich , Rakova Xeniya Mikhailovna
Published: January 2015

Energy saving techniques including the use of alternative energy sources become more and more popular. One of the alternative energy sources is wind. Wind turbines are highly relevant in the areas of wind (such as coasts). This paper proposes a method of increasing the power of wind turbine due to architectural solutions such as streamlining facade by the example of the school. The calculations of the real increase in wind speed and power of the selected wind turbine have been promoted. The payback period graphs of the unit have been discovered in two variants (with changing the façade and without changing the facade). The economic impact has been analyzed. It has been concluded that the proposed scheme is profitable.
The Research of the Effect of Basalt Wool on the Acoustic Isolation of the Floating Floor
Authors: Fidrikova Anastasiia , Grishina Olga , Marichev Alexey , Korsun Artem
Published: January 2015

This paper describes an experimental study of the effect of basalt wool on the acoustic isolation of the floating floor. Calculations and comparison of options flooring with use of acoustic insulation layer and without are shown. Analysis of the results of calculations are made.
Estimation of Industrial Wastewaters Treatment Efficiency by Biotesting
Authors: Andrianova Maria , Bondarenko Ekaterina , Chusov Alexander N.
Published: January 2015

Toxicity of industrial waters at several stages of treatment in model experiment was esteemed in Allium test. It was shown that ability of water to inhibit growth of onions roots decreased together with decreasing of organic matter content in dependence near to logarithmic. Qualitative difference between organic matter in treated and not treated water was observed. In not treated samples diluted to concentrations about 300–550 mgTOC/L toxic effect was 5 times higher than in not diluted waters at final stages of treatment with close content of organic matter (400-460 mgTOC/L). Toxic effect of treated water was close to that of tap water (used as control sample and for wastewater dilution).
Performance Evaluation of High-Rise Complex Construction Depending on Building Site Placement
Authors: Ptuhina Irina , Spiridonova Tatyana , Musorina Tatyana
Published: January 2015

Construction industry is an influential element of Russian economy. It is well known that the main objective of construction for a builder is receiving profit in the form of a difference between the received investment contributions and size of construction cost. Therefore maximum efficiency from implementation of a project will be received by a builder who will carry out construction of the most investment-attractiveness object.Investors do not use certain formalized analytical tools for assessment of situation in regions where a construction object can be potentially placed in most cases. Frequently, investors make the decision on building placement, which based on subjective representation about investment-attractiveness of specific region.The goal of this research is analysis of investment-attractiveness of high-rise building with building site in case of placement in different regions of Russian Federation according to method of A.L. Kaminskiy, including additional unique characteristics of the object.
Definition of Climatic Parameters for Calculation of Energy Performance of Buildings
Authors: Sinđić Grebović Radmila , Spiridonova Tatyana , Vrublevskaya Maria
Published: January 2015

Calculation of energy performance of buildings is defined by European standards in accordance with the Directive 2010/31/EU (EPBD). One of the main goals of the Directive 2010/31/EU is the decrease of energy consumption in the buildings. Standard EN ISO 13790 prescribes the methodology of calculations of energy performance of buildings. The input data for the calculation and their interpretation are defined by European standards related to EN ISO 13790. Climate parameters are defined based on meteorological data in accordance with EN ISO 15927-4. Numerous analyses have shown that the results of calculations depend not only on the chosen method, but also on defining the climate parameters.
Structural Design of Energy Efficient Buildings Using Multi-Objective BB-BC Algorithm
Authors: Milajić Aleksandar , Beljaković Dejan , Čulić Nikola , Vatin Nikolay , Murgul Vera
Published: January 2015

Optimal design of an energy efficient building has to meet two confronted demands: to minimize total cost of construction, and to minimize environmental impact and energy consumption, which is usually obtained by the implementation of expensive insulation materials and equipment. Therefore, optimization task cannot be formulated by a single objective function, but requires at least two functions. Consequently, there is no unique, i.e. the best solution, but a number of more or less acceptable ones among which designer chooses a satisfying one considering given demands and limitations. This paper presents methodology for using the Big Bang – Big Crunch algorithm for optimum design of an energy efficient building that would meet two confronted demands – the lowest price and the lowest environmental impact during the 25 years period. Presented study showed that this approach provides several acceptable solutions among which the decision maker can make a choice in accordance with his/her needs and wishes.
Heat Balance Method Application in Building Energy Performance Simulation
Authors: Harmati Norbert , Jakšić Željko , Vatin Nikolay
Published: January 2015

Simulation-based building performance allows detailed assessment of energy consumption in buildings. This paper presents an energy simulation via HB method of an office building model and outlines the significance and influence of design, construction and HVAC system on the energy consumption. The research was conducted through HB dynamic simulation method which allows flexibility of the thermal model and variability of elements and HVAC system properties, resulting in an energy simulation to outline the major criteria in qualitative enhancement. The findings indicate the influence of each factor on the total energy consumption regarding to the comfort maintenance of users.
Analysis of Micro CHP Potential in Latvia
Authors: Krizmane Maija , Borodinecs Anatolijs
Published: January 2015

The self-sufficiency in the energy field of Latvia is only 35,9 % therefore it is important to think about more efficient and local energy production to provide energy safety whilst reducing the dependence on external factors. [11,12] The current legislation is not favourable for micro CHP unit implementation due to high requirements for electricity sales, however on-site consumption is an option. A good example is Carnikavas Darznieks Ltd micro CHP project, which helped the company to reduce gas consumption of 608 450 m3 and CO2 emissions of 1680 tons per annum. The awareness in Latvia is high due to the experience with CHP plants and there is an interest from foreign companies. With the right application, micro CHP is perspective new technology in Latvia.
Using ANN in Process of Seismic Damage Prediction for Residential Buildings
Authors: Dražić Jasmina , Peško Igor , Mučenski Vladimir , Trivunić Milan , Đorđević Dragana , Vatin Nikolay
Published: January 2015

With the aim of planning preventive measures of seismic protection, estimation of possible damages on building constructions plays an important role. In order to predict the category of damage , a data base was formed out of the data from reports submitted by the commission of the Faculty of Technical Sciences in Novi Sad. The paper presents the research on the influence of the number and structure of input data and the comparative results of prediction of damage category on building constructions for two models of ANN (ANN-1 and ANN-2)
Effectiveness of Soil Reinforcement Based on Complex Ash-Cement Bonder
Authors: Lazarev Yuriy , Chakir Marina , Sukhareva Elizaveta , Ibraeva Yulia
Published: January 2015

This article is about strengthening soil in application of the problem with utilization of ash-and-slag wastes from coil thermal power-stations to reduce the cost of construction of road, to get sufficiently strong of road bases with reinforcing soils, to provide a higher rate of acquisition of durability and higher durability and frost resistance.
Stress-Deformation State in the Rock Massif (Illustrated with the Example of Macedonia)
Authors: Zafirovski Zlatko , Vatin Nikolay
Published: January 2015

Main goal of this article is to introduce an used methodology of analyses for excavation of surge tank enlargement of HEC MATKA1. The way of combining of the methods for analyses of discontinual and continual media are explained. The main information’s about existing geological and geotechnical properties are also given, as a basis for analytical and numerical analyses. Some of the results from the stability analyses of structural controlled instabilities during excavation of water tank are presented. The newly secondary stress – deformation state as a result from enlargement (excavation) is analysed with program Z-SOIL.
Using of Ice for Constructing Islands in the Arctic Conditions
Authors: Karelov Aleksandr , Shkhinek Karl , Belyaev Nikolay
Published: January 2015

Artificial, grounded ice islands built by controlled flooding of the sea ice surface with sea water have been used for exploratory drilling in the Arctic offshore. Islands fabricated from ice are becoming more prevalent as offshore oil speculation in the Arctic gains more interest. Ice has been a strategic building material in the Arctic for the construction of roads, airstrips, housing, and, in the last few decades, as temporary drilling platforms to explore for oil. This article describes various methods of artificial ice building, the advantages and disadvantages of using man-made ice islands for exploratory drilling.
Comparison of Different Types of Transparent Structures for High-Rise Buildings with a Fully Glazed Facade
Authors: Nemova Darya , Reich Elisaveta , Subbotina Svetlana , Khayrutdinova Faina
Published: January 2015

Transparent structures are widely used in the construction of modern high-rise buildings. It is necessary to consider a number of important features in selecting of suitable design of the construction. These are energy efficiency, durability, simplicity of installation, exterior of the building, cost of the construction and payback period. The aim of this work is to determine the most appropriate transparent structure for high-rise buildings with a fully glazed facade according to these requirements. Accomplish this aim such challenges as comparison of characteristics of different methods of glazing, energy efficiency and cost-effectiveness problems were figured out. Basing on this comparison, most suitable transparent structures for the various priority factors have been identified.
Engineering Properties of Sea Ice Ridges in the Barents Sea in 2012-2014 Years for Evaluation of Ice Loads on Offshore Structures
Authors: Gorbunova Kseniia , Shkhinek Karl
Published: January 2015

Results of studies of ice ridges in field conditions are presented. Ice ridges investigated in the Barents Sea the proximity of the South-East of Svalbard archipelago. Five ice ridges are surveyed during research cruises in 2012-2014 years. Main engineering properties ice ridges as thickness of consolidated layer, height of sail and depth of keel were obtained. Results of research are of primary importance for evaluation of ice loads in studied area in Barents Sea.
Ice Regime for Basins and Pumped-Storage Facilities
Authors: Bakanovichus Natalya , Vatin Nikolai
Published: January 2015

The article deals with various optional combinations of upper and lower basins in pumped-storage power plants (PSPP) which determine ice conditions that may appear on water surfaces, headwater discharge basins and slopes basins. There are also examples of calculation methods of ice regimes that are given in this article.
Ensuring the Reliability of Earth Dams in Complex Hydrogeological Conditions
Authors: Bulatov Georgiy , Vatin Nikolay , Nemova Darya , Ibraeva Yulia , Tarasevskii Philipp
Published: January 2015

In the considering problem usual tasks of designing ground dams (evaluation of filter strength, compressibility and ground permeability) are overlaid by new tasks, that have never touched upon earlier, that provide reliability of earth dams under extreme conditions and that are exposed by new additional forces such as intensive deformation and curvature of base. Here are dependences allowing determination of accepted values of earth surface deformation of ground dams on undermined territories. Using this methodology, you can compute required constructively technologic protection measures. Solution of such problems as predicting behavior and degree of reliability from external influence of a dam at given expected deformations, - can be brought into action. Prediction of conventional dams reliability may been carried out without underworking.
Enhanced Mualem-Van Genuchten Approach for Estimating Relative Soil Hydraulic Conductivity
Authors: Terleev Vitaly , Badenko Vladimir , Guseva Inna , Mirschel Wilfried
Published: January 2015

New theoretical justification for the function of soil differential moisture capacity (dependence of the relative water volume content on the capillary pressure) and its antiderivative is presented. New method is based on the concept of capillarity and the lognormal distribution of the effective radii of pores. Relative hydraulic conductivity of soil is calculated with usage of these functions and Mualem's approach. Hydrophysical parameters have been interpreted and evaluated on the base of some physical and statistical soil characteristics. Also the approximation for functions of water-retention capacity and relative hydraulic conductivity of soil has been proposed.
Two-Component Incompressible Fluid Model for Simulating the Cohesive Soil Erosion
Authors: Zakharov Yuri , Zimin Anton , Nudner Igor , Ragulin Vladimir
Published: January 2015

Non-stationary inhomogeneous system of the Navier–Stokes equations with variable viscosity depending on the density has been used for modeling the process of the cohesive soil erosion. Value of the density has been determined by the convection–diffusion equation. For solving the obtained system we have used an algorithm consisting of the splitting scheme on physical factors and the predictor–corrector method. The system has been solved on the staggered grid by the grid method. The results of calculations for two-dimensional and three-dimensional problems are presented.
Testing of the Mechanical Properties of Masonry Walls – Determination of Compressive Strength
Authors: Radovanović Željka , Sinđić Grebović Radmila , Dimovska Sretena , Serdar Nina , Vatin Nikolay , Murgul Vera
Published: January 2015

This paper will present testing of masonry walls made from clay block and concrete block. Experimental testing of the walls is done in the laboratory of the University of Civil Engineering in Podgorica within the national scientific research project "Seismic risk reduction in buildings of stone and brick". This paper presents the results of testing samples of walls built with the tested masonry elements and mortar. Characteristic compressive strength of the walls and elasticity modules were obtained. An analytical approach to determining the characteristic compressive strength and elasticity modules of masonry walls is analyzed in accordance with the applicable standard of Yugoslavia PIOVS'91, European standards EN 1996-1-1: 2005 and the American standard ACI 530.
An Impact of Carbon Nanostructured Additives on the Kinetics of Cement Hydration
Authors: Frolov Artem , Cherkashin Artemiy , Akimov Luka , Vatin Nikolai , Koltsova Tatiana , Nasibulin Albert , Tolochko Oleg , Chumadova Ludmila
Published: January 2015

There are supplements that could accelerate or slow down the process of setting and formation of the cement stone structure. After examining the effect of these particles, we can predict how they could influence on the growth of concrete strength. It is possible to assess the effect of supplementation activity using the thermo-kinetic method by exothermic effect, which is obtained by wetting and hydration of cement. A calorimetric research of the effect of cement-carbon material was held in this article.
The Influence of Based on Polyalcohols Additive on the Cement Paste Shrinkage
Authors: Barabanshchikov Yuri , Arkharova Anna , Ternovskii Maksimilian
Published: January 2015

The influence of a shrink-resistant “Estrifan Additive RCL” additives on the cement paste shrinkage was researched. The cement paste shrinkage is reduced when we use this additive. When the content of additives is more than 2 % there is expansion in the initial stage of hardening. The extension period is longer and the value of expansion deformation is higher, the additive dosage is higher. The presence of superplasticizer Muraplast FК48 enhances the initial expansion effect and shrinkage decrease by reducing the rate of evaporation of water. On the contrary, in a separate action superplasticizer increases the cement paste shrinkage.
Property Changes of Thermal Insulation Material due to the Effects of Environmental Conditions
Authors: Vatin Nikolay , Pestryakov Igor , Avdeev Dmitriy
Published: January 2015

Ventilated facades are widely used in modern energy efficient building, and it leads to topical issue whether it is important or not to stick to assembling terms of such kinds of facades. The first thing to do during the ventilated facades installation is to built in the mineral-cotton insulant which will be later protected by vapor proof material. Thus, the shield obtained on the exterior side of the building in the aggregate with ventilated clearance and facing material form a system with high insulation and resistant to environmental attacks. This article observed a situation in which the terms of ventilated facades installation were broken after the primary stage (not more than 90 days). The works were stopped for 1.5 year after fixing the heat-insulation material to the inclosing walls of the building. As a result, insulants were exposed to significant temperature and humidity changes, wind forces and UV rays. The main objective of this research is to determine the suitability of insulating material for further use taking into account changes in its basic parameters, which are determined by laboratory tests.
Fiberglass Reinforcement for Concrete
Authors: Barabanshchikov Yury , Belyaeva Svetlana , Avdeeva Arina , Perez Maikel
Published: January 2015

The features of the application of FRP reinforcement for concrete reinforcement. The results of mechanical tests. Shows the influence of the proportion of glass reinforcement on the physico-mechanical properties of rod fiberglass reinforcement.
Fireproofing Cemented Fiber Vermiculite-Concrete Composites with Application Volcanic Ash
Authors: Kretova Valeria , Hezhev Tolya , Zhukov Azamat , Hezhev Khasanbi
Published: January 2015

Are considered fireproof fiber-vermiculite-concrete composites with application of a portland cement, swollen vermiculite, volcanic ash, quicklime, plaster, a basalt fiber and saponified resin. Results of researches of composition and physicomechanical properties of fiber-vermiculite-concrete composites, experimental tests and theoretical researches of fire resistance two-layer reinforced cement elements are given
Kinetics of Hydration and Hardening Processes in Clinkerless Slag-Alkaline Binder Materials
Authors: Petrova Tatyana , Prokofieva Valentina
Published: January 2015

The purpose of the present work is to research the process of hardening clinkerless slag-alkaline binder materials during the early stage of interaction between the ground granulated blast-furnace slag and the alkaline component by the thermokinetic method. The amount of heat emitted during the interaction between slag and alkaline component, and the influence of the duration of slag pre-hydration period upon this process have been assessed. These values were compared to similar values for binder materials based on portland cement. It was shown that ageing has significantly larger influence on heat emission during hydration of portland cement and on concrete strength.
We have elaborated in more detail the mechanism of hydration reaction of slag-alkaline binder materials starting at the level of active centers on the surface in accordance with the process of self-decelerating forming of crystallization centers. As slag grains are covered with a layer of hydrates, kinetics of hydration till the end of reaction is regulated by the process of diffusion that depends on the degree of structural irregularity.
Dependence of Relative Decreasing in Strength by Rate of Strain for the New Rapid Method for Determination of Concrete Frost Resistance
Authors: Pertseva Olga , Nikolskiy Sergey
Published: January 2015

The task of the project is obtaining the dependence between the relative decreasing of strength and rate of strain and substantiation of the new method for determination of concrete frost resistance. It has been analytically proved that using concrete’s rate of strain ε as a measure of damage, instead of decreasing of tensile strength R, increases freeze-thaw resistance’s accuracy of estimation a lot under otherwise equal conditions by the time of freeze-thaw cycling. Also it has been experimentally shown that ratio of relative decreasing R to ε in direction, perpendicular to compression, is assumed to be independent on values R and ε for a given concrete and on the ways of achieving them during mechanical or freeze-thaw cycling. To determine the dependence δR/R by ε (z) 8 specimens were tested by non-destructive method (RU 2 490 631) and two baths of 50 specimens by basic method (thermo cycling). Results of the non-destructive method are different from results by basic method for 6,3%. Dependence of relative decreasing in strength by rate of strain is near to linear and, therefore, value of z is constant. Taking this into account patented methods for estimation of concrete’s freeze-thaw resistance as per values R and ε received after freezing and thawing cycles of some specimens and their postlimenary failure by linear compression was substantiated.
Use of Epoxy Fluoroplastic Coatings in Friction Pendulum Bearings
Authors: Smelov Alexander , Ivanochkin Pavel , Tselykh Alexey
Published: January 2015

In this paper, we consider the possibility of using, in friction pendulum bearings, multilayer friction proof coatings based on polytetrafluoroethylene compounds modified by nanoscale spinels such as magnesium, zinc and chromium. The tribological effect of applying the coating is achieved by formation of a friction transfer layer. For better wear resistance, we applied a multilayer coating with a power frame covered using electrospark coating. We performed an experimental research of bushing samples and various coating fluoroplastic bases. The research on a friction machine “SMT-1” has shown the effectiveness of epoxy fluoroplastic composition as an anti-friction coating in comparison to other types of fluoropolymer bases.
Analysis of Behavior of a Lattice Girder According to Theory of Plasticity with Link Elements
Authors: Ćosić Marina , Varga Vladimir , Stanković Jelena , Maneski Miloš , Vatin Nikolay
Published: January 2015

The purpose of this work is to show the way that leads to losing of stability of a lattice girder, by gradual becoming plastic of elements. Elements that are allowed to become plastic are inserted into the program SAP2000 as link elements of appropriate characteristics, whereby there is made a numeric modeling of a problem. Finally, the possibility of significant reducing of lattice girder's weight is shown, which has a very favourable economic effect as a consequence
Unsteady Temperature Condition of the Enclosure Structure
Authors: Petrichenko Mikhail , Tarasova Darya , Nemova Darya
Published: January 2015

In this article the influence of external temperature fluctuations on temperature of the enclosure structures are defined, a selection of optimum heating system for thermal energy saving are offered, thickness of penetration layer of a temperature wave are defined. Fourier's differential equation of heat conductivity process in a solid body is solved and analysed.
Unsteady Airway as an Effective Method of the Ice Melting Prevention on the Building’s Roof
Authors: Suslova Anna , Sivokhin Alexandr , Petrichenko Mikhail
Published: January 2015

The presence of ice crusts and icicles on roofs is an urgent problem since they influence on the people safety and property which could be situated unde roof cornices. There are a lot of methods to stop icicle formation on the roofs. At present article is considered an efficiency of an unsteady airway. The unsteady airway can change its section area depending on the wind speed. Such a constriction allows entering into the attic a big volume of cold air. At that сontribution is find a speed of snow melting on the roof featured by the unsteady airway. Speed of the snow melting influence the speed of ice crusting. By estimating these factors can be made a conclusion that the unsteady airway helps to reduce a quantity of ice dams.
Two-Dimensional Surface Fatigue Crack Propagation and its Finite Element Simulation
Authors: Guchinsky Ruslan , Petinov Sergei
Published: January 2015

Fatigue crack growth rate at the plane stress is predicted by Paris equation, associating it with the stress intensity factor (SIF), generalized parameter of the elastic stress field near the crack tip. The finite element method allows modelling of the incremental crack growth in the plates, where the finite element grid should be re-meshed on each crack growth step fitting the first principal stress planes. However, the linear fracture mechanics format (LEFM) based evaluation of the two-dimensional fatigue cracks does not provide always the correct crack front assessment and appropriate life-predictions. It is shown that approach using the damage accumulation simulation and strain-life criterion may be promising in analysis of the two-dimensional cracks. Application of the approach is illustrated. The simulation results are in good agreement with the experimental data.
Modeling Nonlinear Deformation and Destruction Masonry under Biaxial Stresses Part 1 – Masonry as Simulation Object
Authors: Kabantsev Oleg
Published: January 2015

Masonry is a complex multicomponent composite consisting of dissimilar materials (brick / stone and mortar). Masonry deformation process under loading depends on the mechanical characteristics of the basic composite materials, as well as of the parameters of the elements defining binding between brick and mortar being the interface elements. Traditional methods of masonry modeling are based on the use of generalized ("effective") mechanical properties of the composite as a continuant homogeneous continuant medium. This paper presents an overview and analysis of continuant masonry models adequately reflecting the process of elastic, and in some cases elastic-plastic masonry deformation within the composition of stone structural elements. The paper provides analysis of the experimental research results of masonry behaviour in a biaxial stress state at primary stresses of opposite signs; identifies masonry destruction mechanisms complying with the conditions of stress state. The work demonstrates the key role played by interface elements in the formation of masonry destruction processes. Based on destruction mechanisms deduced from experiments, there was developed a discrete model of masonry. A system of masonry strength criteria was proposed corresponding to the biaxial stress state conditions at primary stresses of opposite signs. For purposes of studying the elastic-plastic deformation and destruction of masonry, there was developed a technology of numerical experiment performance using calculation technologies with a stepwise tracking of stress-and-strain state, at step-by-step loading. The scope of this paper includes verification of modeling method and technology of numerical experiment at various parameters of interface elements defining binding between bricks and mortar.
Local Buckling of Cold-Formed Steel Members with Edge Stiffened Holes
Authors: Garifullin Marsel , Trubina Darya , Vatin Nikolai
Published: January 2015

Cold formed steel members with edge stiffened holes are a new generation of cold formed members recently developed by the building industry. Very little research has been performed on such sections to determine their local and distortional buckling capacity. This article provides the numerical results of elastic local buckling analysis of cold-formed lipped channels with edge stiffened holes. For flexural elements values of critical buckling moments are calculated and the influence of hole spacing and diameter on elastic buckling capacity is determined.
Calculation of Combined Structure and Installation Roof Systems Taking into Account Structural Nonlinearity Factor
Authors: Egorov Vladimir , Belyy Grigory
Published: January 2015

Stress and strain state of hybrid (combined) systems including flexible and rigid elements is studied in the article. Theoretical approach is presented. The feature of the systems studied is described, i.e. structural nonlinearity. Numerical analysis is presented. It is pointed out that vibrations of such structures upon conditions of resonance differ from those of classical bar structures, i.e. if for rigid bar systems the amplitudes of vibration at resonant disturbance increase monotonously, in combined (hybrid) system alternate switching off tie-bars stabilizes the amplitude of vibration at a certain value and transfers vibrations in the beating mode that can be considered as an internal vibration absorber.
Crack Resistance Criteria for Reinforced Concrete Beams with Corrosion Damage in Strength Resource Assessment
Authors: Kolchunov Vitaly , Androsova Natalia , Kolchina Tatyana
Published: January 2015

In the framework of ultimate state calculation methods the paper presents some propositions for stress-strain state, crack resistance analysis and failure state of reinforced concrete structures with corrosion damage at supports. The work concerns the durability of concrete and reinforced concrete elements with corrosion damage. The theory for reinforced concrete with corrosion damage is presented for plane stress state
Mathematical Analogy between Non-Uniform Torsion and Transverse Bending of Thin-Walled Open Section Beams
Authors: Rybakov Vladimir , Sergey Alexander
Published: January 2015

The objective of this work is to identify and make an analysis of correlation between functions of bimoments and function of bending moments arising in the beams under the same loads. This article shows the possibility of using a diagram of bending moment multiplied by a factor as a diagram of bimoment. The maximum deviation between diagram of bending moment and diagram of bimoment made up 3.6 % of maximum bending moment in case of uniformly distributed load on one side of fixed supported beam.
Justification of Using Delta-Functions in the Theory of Shells Featuring Irregularities
Authors: Karpov Vladimir , Kondratyeva Lidiya
Published: January 2015

The delta-functions are used in calculation of the building structures to determine irregularity places, but the delta-function proper is a limiting function featuring no geometrical interpretation. In order to justify correctness of its application, it is necessary to carry out the limiting transition based on the method of variation limiting transformations. Consideration is given to the shallow shells supported by the narrow ribs or featuring jogs of the middle surface. The places of discrete variation of shell thickness or its curvature will be set by means of singular columnar functions. The limiting transition from such functions to delta-functions is used to obtain correlations for the rib shells and the shells featuring the middle surface. This is the way to justify a possibility of using delta-functions in the theory of shells featuring irregularities. At that, the equilibrium equations get simplified and, at the same time, the calculation accuracy gets lost.
Calculation on Formation of Longitudinal Cracks in Reinforced Concrete Structures Taking into Account Nonlinearity of Concrete Straining
Authors: Veselov Anatoliy , Pukharenko Yury
Published: January 2015

Actuality of study of the problem of longitudinal crack formation along reinforcement taking into account concrete nonlinear strain is pointed out in this article. It is known that at collaboration of steel and concrete plastic strains occur in concrete surrounding bar. Previously, in the work [6], solution on determination of splitting cracks at elastic work of concrete in the area of active bond to steel was proposed. In this article, theoretical solution on determination of longitudinal cracks both in supporting area and in the area of collaboration of steel and concrete between cracks along element is suggested. For establishing equations taking into account inelastic work of concrete, the theory of plastic properties suggested by G.A. Geniev was used. Component stress-strain relation is recorded by analogy with studies performed by G.A. Geniev and N.N. Malinin. At that, design dependencies are linked with normative factors of concrete, such as concrete ultimate tensile strength, Poisson ratio and concrete elastic strain ratio at stretching. All this allowed to significantly simplify the use of expressions offered.
Modeling Nonlinear Deformation and Destruction Masonry under Biaxial Stresses Part 2 - Strength Criteria and Numerical Experiment
Authors: Kabantsev Oleg
Published: January 2015

Masonry is a complex multicomponent composite consisting of dissimilar materials (brick / stone and mortar). Masonry deformation process under loading depends on the mechanical characteristics of the basic composite materials, as well as of the parameters of the elements defining binding between brick and mortar being the interface elements. Traditional methods of masonry modeling are based on the use of generalized ("effective") mechanical properties of the composite as a continuant homogeneous continuant medium. This paper presents an overview and analysis of continuant masonry models adequately reflecting the process of elastic, and in some cases elastic-plastic masonry deformation within the composition of stone structural elements. The paper provides analysis of the experimental research results of masonry behaviour in a biaxial stress state at primary stresses of opposite signs; identifies masonry destruction mechanisms complying with the conditions of stress state. The work demonstrates the key role played by interface elements in the formation of masonry destruction processes. Based on destruction mechanisms deduced from experiments, there was developed a discrete model of masonry. A system of masonry strength criteria was proposed corresponding to the biaxial stress state conditions at primary stresses of opposite signs. For purposes of studying the elastic-plastic deformation and destruction of masonry, there was developed a technology of numerical experiment performance using calculation technologies with a stepwise tracking of stress-and-strain state, at step-by-step loading. The scope of this paper includes verification of modeling method and technology of numerical experiment at various parameters of interface elements defining binding between bricks and mortar
Deterministic and Probabilistic Approach of Capacity of the Elements of a Lattice Gird
Authors: Ćosić Marina , Krstić Manojle , Filipović Sandra , Milojević Ivan , Vatin Nikolay
Published: January 2015

The problem that this work deals with, relates to the analysis of behavior of the lattice girder joint. We will analyse a strained diagonal, roof lattices, presented on picture 1, in which the maximum influence of a normal force is 509.1kN and there are two profiles L100x100x10 adopted, both turned backwards (to each other). The connection between the angle bar and joint sheet metal, 15mm thick, is achieved via 4 angle stitches, 7mm thick and 250mm long, that will, besides diagonal itself, be the topic of this work. Steel concerned is S235.
Multimodal Pushover Analysis for R.C. Bridges
Authors: Crespi Pietro , Franchi Alberto , Giordano Nicola
Published: January 2015

In recent years, Italian technical-scientific community has increased its interest on the evaluation of the seismic response of existing structures. Among this wide range of structures, reinforced concrete bridges stand out for their strategic relevance and technical complexity. Most of these structures were built between 60ies and 70ies, according to design procedures which ignored nowadays knowledge in seismic engineering. Thus, the necessity to evaluate the real strength capacity of these structures with modern analysis techniques has become essential, leading to the determination of their safety level in case of an earthquake. In particular, for the assessment of several bridges of a motorway network, a multi-modal pushover analysis approach has been considered. This analysis technique allows considering the nonlinear behaviour and the complex dynamic response of such structures without exceeding in high computational costs. Some basic rules were defined (constitutive laws of materials, finite element type, plastic hinge models, etc.) for the modelling of bridges, in order to guarantee homogeneous comparable results among different structures of a network. At the end, some of the results are compared to see the variation of the verification level with respect to both the number of modes considered and the analysis’s accuracy in terms of number of loading steps.
On Strength Reserve Assessment for Prismatic Folded Plate Roof Structures
Authors: Kolchunov Vitaly , Osovskih Evgeny , Afonin Pavel
Published: January 2015

The paper presents the results of experimental studies and numerical simulation of straining and failure of reinforced concrete folded-plate roof structures in limit and out-of-limit states performed on models and real structures, taking into account the combined mechanical loads and environmental actions. The results of the study show that in the process of reconstruction design for concrete prismatic roof structures of operated industrial and public buildings, along with the traditional limit state methods of calculation it is reasonable to carry out a residual strength reserve analysis.
The Results of Experimental Determination of Air Output and Velocity of Flow in Double Skin Facades
Authors: Petrichenko Mikhail , Vatin Nikolai , Nemova Darya , Olshevskiy Vyacheslav
Published: January 2015

Double skin facades very popular in this time. They are applied for construction of new buildings and for reconstruction. This paper to try to consider the main problems which appear during the work with the double skin facades. In paper are presented dependence of average velocity of air flow as functions from the geometrical sizes of the ventilated air gap of double skin facades and air output as functions from the geometrical sizes of air gap. This dependences are received experimentally. The received dependences can be used at design of double skin facades for the purpose of obtaining the optimum sizes of an air gap.
Finite-Element Simulation of Progressive Cross-Section Ellipticity of Single Crystal Samples under Uniaxial Tension
Authors: Beliaev Mikhail , Semenov Artem S.
Published: January 2015

The influence of the crystallographic orientation, the level of axial strain and the test temperature on the progressive cross-section ellipticity of single crystal samples under uniaxial tension is analyzed in order to improve axial strain measurement in experiments. The direct three-dimensional finite element modeling of elasto-plastic deformation process of single-crystal initially cylindrical samples is used with taking into account finite strains, slip mechanisms and necking.
Experimental Investigation and Finite Element Simulation of Fracture Process of Polymer Composite Material with Short Carbon Fibers
Authors: Maniak Ivan , Melnikov Boris , Semenov Artem S. , Saikin Sergey
Published: January 2015

This work is devoted to the research of mechanical and strength properties of polymer composite material with short carbon fibers produced by injection molding technology. The material is PEEK90HMF20 with 20 % of carbon fibers mass fraction and based on polyether ether ketone (PEEK) polymer matrix. Mechanical and strength properties were researched on samples that had been cut from molded plates. A set of tension tests was performed and stress-strain diagrams of samples with different orientation in relation to the global direction of injection were obtained. Two-step homogenization procedure and pseudo-grains failure model were used to describe composite material behavior. The material model parameters were calibrated with experimental data by means of reverse-engineering procedure. Finite element simulation of tension tests was performed to check the quality of built model from the point of view of its ability to predict failure.
The Formation of Cracks in Cast-Iron Molds during the Casting of Zinc Blocks
Authors: Ivanov Mikhail Alekhsandrovich
Published: January 2015

The article considers the problem of cracks formation in cast-iron molds during the casting of zinc blocks. The analysis of casting technology for manufacturing of cast-iron molds is performed. Changes of the construction of cast-iron molds is implemented to ensure the directional solidification. The analysis of thermal cycles of cast-iron molds during its operation is performed. It is established that the most dangerous moment of crack formation is the beginning of the pouring of molten zinc in the cold cast-iron mold. The new composition of the separation insulating coating, which reduces thermal shock and the probability of crack formation is developed.
The Current State-of-the-Art in the Field of Material Models of Concrete and other Cementitious Composites
Authors: Hokes Filip
Published: January 2015

The topic of this paper is the short review of current state-of-the-art in the field of material models of concrete and its utilization for numerical analysis of concrete and prestressed concrete structures. The problem of compiling constitutive relations for numerical simulation of concrete structures is not yet closed. It is caused by different behavior of concrete in tension and compression. Due to formation and development of cracks it is necessary to describe material model of concrete in tension as precisely as possible. The paper aims to create a brief historical overview in this field and then aims to create a short summary of current approaches that were published in conference contributions and in journals during recent years.