bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impulse excitation technique and its application for identification of material damping: an overview
Authors: Popov I I , Shitikova M V 
Published: November 2020

Abstract
The recent work presents an overview of the papers devoted to the application of Impulse Excitation Technique (IET) for the measurement of internal friction in different materials. IET is an advanced method to measure such materials’ characteristics as Dynamic Young’s and Share Moduli, Dynamic Poisson’s Ratio, Damping, to investigate the deformation behavior, softening phenomena and relaxation mechanisms and phase transformations in different materials. The experimental studies can be performed at both, room and high temperatures. Due to its simplicity, low cost, high accuracy and reproducibility it may take the leading position among the other non-destructive testing methods and techniques.
Comparative analysis of thermofluctuation constants of polyvinyl chloride plates obtained in various ways
Authors: Erofeev A V , Gorokhov T I , Drannikov R N 
Published: November 2020

Abstract
To reliably predict efficiency of solids, it is necessary to know the values of their thermofluctuation constants, which are determined by experimentally obtained data using graphical, graphoanalytical, and mathematical methods. Using the same initial data, the thermal fluctuation constants were determined by different methods. The graphical method is presented by calculation using graphs built on graph paper. The graphic-analytical method uses MS Excel. The mathematical method operates directly with equations instead of a graphical representation. It is shown that the chosen method of obtaining the constants has a significant effect on the final result. It is recommended to use a mathematical method when determining the thermal fluctuation constants.
Algorithm formulation for adjusting the estimated composition of concrete mixture taking into account relevant properties of the raw materials
Authors: Koshelev V A , Kovaleva O I , Averina G F 
Published: November 2020

Abstract
This article deals with the research dedicated to the formulation and testing algorithm of water amount adjustment tempering while producing concrete mixtures depending on raw material characteristics. The algorithm is intended for an automated quality control system of concrete mixtures of raw components, providing continuous data collection in real time. The article provides the necessity of automatic quality control implementation and adjusting the calculated compositions of concrete mixtures based on them. There is the discussion of factors discouraging the formulation and implementation of the given systems at the existing production of reinforced concrete products. There were formulated the ways of solving the problems, the scientific significance of the proposed projects was proved. There was revealed the main parameter of the concrete mixture, which provides the concrete quality obtained on its basis and factors influencing it associated with the physicochemical characteristics of raw materials are shown.
Development of a simulation model for the supply of spare parts for heating equipment
Authors: Lvovich I Ya , Preobrazhenskiy A P , Choporov O N 
Published: November 2020

AbstractThe problems associated with the supply of spare parts for heating equipment are considered. The main stages of development of a simulation model that allows you to simulate the incoming flow of applications for different types of parts for heating equipment are presented. The analysis of the time series of the supply of parts for heating equipment. Then there are opportunities for modeling autocorrelated flows by ordering for spare parts that have a certain relationship between each other according to the items of the item. Cross-correlation and autocorrelation functions of time series were considered, and it was revealed that these functions are not similar to each other.
Estimation of concrete durability using kinetic characteristics of its destruction
Authors: Popov V P , Popov D V , Davidenko A Yu 
Published: November 2020

Abstract
The article deals with the research results of concrete destruction processes by different types of external impact. The materials were obtained by the Samara research school of architecture and construction academy. The paper analyzes the process of concrete destruction and determines its main flow stages, depending on the amount of released energy of crack formation. Initial parameters of concrete structure are proposed, including: surface energy, modulus of elasticity and Poisson’s coefficient. The authors paid special attention to kinetic characteristics including tendency of concrete crack formation and crack formation intensity. The combination of kinetic characteristics is given as a criterion for concrete durability assessment. Quantitative dependence of kinetic characteristics on moisture and porosity is confirmed.
A ‘Building material science glossary’ mobile application for Chinese international students
Authors: Pogorelov S N , Bagdueva A V , Kolmogorova A O 
Published: November 2020

Abstract
Chinese international students encounter a variety of difficulties in their education at Russian universities. Overcoming the language barrier and adjusting to new social and learning environment are thought to be the major factors for successful training abroad. However, there is also one serious challenge that Chinese students face. Professional disciplines, in particular technical ones, are characterized by a high concentration of terms. Knowledge of specialized technical words has a strong impact on the academic development of the students. Greater vocabulary size is a main component for understanding written learning materials and for effective oral interacting with faculty members. However, just few Chinese-speaking students demonstrate a sufficient level of competence in technical Russian. In this regard, the paper raises the issue of developing language proficiency under a course in construction. On the example of building material science the authors consider compiling a bilingual glossary designed as a mobile application. Such a ‘mobile’ glossary can help Chinese international students, whose major is construction, to successfully gain subject knowledge.
Study of natural self-healing of materials based on inorganic binders
Authors: Chernykh T N , Bondarenko S A , Zimich V V 
Published: November 2020

Abstract
The study of natural self-healing of materials based on inorganic binders has been carried out. The age of the study was one month after loading with cracking. Microscopic analysis of samples with cracks based on Portland cement, oxychloride cement and gypsum showed that all studied materials are capable of filling cracks on their own. The filler, such as calcium carbonate or gypsum dihydrate, can have a sufficiently high strength so that a selfhealing effect is present. A filling agent such as magnesium hydroxide cannot have strength, and then only the crack is filled without restoring strength. Filling of cracks at the age of up to one month is insignificant and does not exceed 0.5 microns. This is not enough to fill large cracks. For modern building structures, natural self-healing is ineffective. This requires the use of artificial methods of self-healing in modern building structures.
Calculation of the circular plates’ stability in stresses
Authors: Tyukalov Yu Ya 
Published: November 2020

Abstract
The method is proposed for solving the plates stability problems by the finite element method based on piecewise constant approximations of moments. The solution was obtained on the basis of the principles of minimum additional energy and the possible displacements. To ensure the moment fields equilibrium, the equilibrium algebraic equations of grid nodes are compiled using the possible displacements principle. Such equilibrium equations are written as a system of linear homogeneous algebraic equations. Using the Lagrange multipliers method the equilibrium algebraic equations are including to the functional. The proposed method ensures the critical stress convergence to the exact value from below, which provides reserve of the plate stability.
Methodology of calculating the moisture content of soil reserves during the construction of an earth bed
Authors: Aleksikov S V , Leskin A I , Gofman D I 
Published: November 2020

Abstract
The authors propose a methodology for calculating the moisture content of the ground reserves based on the introduction of a moisture factor of the construction area, which is the ratio of annual amounts of atmospheric precipitation to the maximum possible evaporation for reasonable planning of organizational and technological measures for the construction of an earth bed. The proposed technique makes it possible to determine the design moisture of any soil type in the reserve according to the data of observations of precipitation and air temperature of the region, where works are performed. The dependencies, obtained by the authors, have a theoretical justification, a close correlation connection, are provided with materials necessary for mass calculations, all parameters are physically clear, which allows to use them for long-term prediction. There can be no malformations of water-thermal balance of soil of the earth bed, when calculating according to the proposed formulas.
Improving calculating theory of multiple-cavity reinforced concrete floor panels
Authors: Vasilyev A S , Plehanova E A , Xiaolong Bai 
Published: November 2020

Abstract
It is a known fact that core slabs are introduced as I-shaped beams (T-beams) to simplify calculations and are considered according to the beam theory. However, such a view may cause erroneous calculation results. This is particularly evident when calculating the second group of limit states. The aim of this survey is to examine the influence of the cross current representation of core slabs for samples of various length by defining the impact of these factors (the shape of the cross-section and length) on the bearing and nonrigid capacity as well as a cracking load. The paper makes the calculating theory of reinforced concrete framing clear, in particular, core slabs according to the limit states. The author dwells upon samples of slabs of various lengths with a natural cross-sectional shape in comparison with I-shaped samples of similar length. The author should emphasize that it is assumed both in analytical calculations and in software based on FE analysis in order to save time and computing resources. The author performs a computational investigation of core slabs in a nonlinear setting with forming a plastic centroid in the middle of a slab in the study. It is found out that the slab length affects the calculation results of the considered shapes. The shorter the length, the clearer cut the deviation in the load deflection plots.
Mixed finite element formulation based on the discontinuous stress approximation
Authors: Lukashevich A A , Lukashevich N K , Kobelev E A 
Published: November 2020

Abstract
The paper is devoted to the development of the mixed form of finite element method for the calculation of constructions and structures. We consider the approach based on the approximation of discontinuous stress fields and the use of the penalty function method to satisfy the equilibrium equations. It is shown that the continuity of both normal and tangential stresses only on the adjacent sides of the finite elements contributes to the expansion of the class of statically admissible stress fields. At the same time, the consistent approximation is provided, both of the main part of the functional of additional energy, and its penalty part. Using the given approach, solutions of some problems were obtained and analyzed, in particular, the calculation of the cantilever beam-wall. The results obtained were compared with the decisions on the FEM in displacements and stresses, as well as with the exact solutions. It is shown that solutions based on the approximation of discontinuous stress fields in mixed form FEM converge to exact values from below and are more flexible in comparison with the solutions obtained by FEM in displacements. In addition, the accuracy of determining stresses is higher here.
Optimizing the centrally compressed step-variable stiffness rods
Authors: Grebeniuk G , Lukin E , Nagaitseva E 
Published: November 2020

Abstract
The article deals with the optimization parameters of centrally compressed step-variable stiffness rods, with the material that is able to work both within and out of proportionality. The following algorithms are developed: the maximization algorithm of loading critical parameter at the given volume of the rod material, and the minimization algorithm of the rod material volume observing the restrictions on durability and stability, taking into account the own weight of the rod. The analysis of the optimization results is carried out and the recommendations on calculation and rod design are offered.
Modeling of the complex “Ground Base-Foundation-Construction-External Influences” taking into account the cyclic technogenic vibrational loads
Authors: Grecheneva A V , Dorofeev N V , Pankina E S 
Published: November 2020

Abstract
The article is devoted to the development of a mathematical model of the complex “ ground base-foundation-construction-external influences” taking into account the cyclic technogenic vibrational loads. The mathematical model is used in automated systems of geotechnical monitoring. The coefficients for a qualitative separation of the types of vibrational technological impact and its quantitative presentation are introduced into the model. These coefficients provide the implementation of the criteria for safe and efficient operation of the foundation and the structure as a whole. At the computer modeling, the dependence of the strength parameters in the complex “ground base-foundation-construction-external influences” was evaluated. It is established that the calculation using the developed mathematical model allows increasing the sensitivity to early detection of a decrease in the strength characteristics of the foundation structure by an average of 24%.
Economical reinforced concrete overpass. Graphical method of calculation
Authors: Makarov A V , Kalinovsky S A 
Published: November 2020

Abstract
The article considers the issue of designing cost-effective underpasses on the roads. With the wide spread of multi-level transport interchanges, the relevance of this issue is constantly increasing. Currently, mainly designed two and three-span girder viaducts (and most three-span), therefore, in the framework of this research, a comparative analysis of two-span and three-span overpass from the point of view of economy of their construction. It is known that the economic efficiency of bridge structures depends significantly on the size of the cross sections of their structural elements, which in turn depend on the internal forces arising in them from the impact of the entire complex of operating loads. As a result of calculations of internal forces in continuous beams, which are structural elements of overpasses, a graphical method for determining bending moments in two-span continuous beams is proposed, which has sufficient accuracy from an engineering point of view on the one hand and allows speeding up the design process on the other hand. In the process of developing this method, a graph of changes in the bending moments in the main beams of span structures of bridge structures is drawn up depending on the ratio of permanent and temporary loads acting on them.
Experimental research methodology for the deformation of RC frame under instantaneous loss of column
Authors: Savin S Yu , Kolchunov V I , Korenkov P A 
Published: November 2020

Abstract
In recent years, numerous experimental and especially numerical studies have been conducted in order to study the mechanisms of the resistance of reinforced concrete building frames to progressive collapse during the instantaneous removal of one of the columns. Analysis of these researches shows that almost all study deals with strength performance of RC structural elements under quasi static or instantaneous loss of column. At the same time, a number of numerical and analytical studies of the progressive collapse behaviour of steel moment frames as well as fragments of RC moment frames indicates that loss of bearing capacity of structures can be associated with buckling behaviour. Therefore, using the theory of functional similarity, a physical model of the reinforced concrete frame of a multi-storey building and a methodology for experimental studies of the buckling and fracture of this structural system under instantaneous loss of the corner column are proposed.
X-ray limited-angle tomography of cracks
Authors: Likhachev N A 
Published: November 2020

Abstract
The aim of this work is to obtain estimates of the accuracy of the x-ray limited-angle tomography method for determining the shape and size of internal cracks in large-sized reinforced concrete structures. A fan-beam registration scheme with a source moving along a circular arc is considered. For reconstruction, we use the fan-beam transform inversion formula and the algebraic method ART. By means of numerical simulation, the dependences of errors of the first and second kind on the mutual orientation of the central beam and the direction of the crack, the angular size of the source trajectory and the noise level are obtained.
Geometrically nonlinear buckling analysis of truss under mechanical and thermal load based on mixed finite element formulation
Authors: Quyen Vu Thi Bich , Tien Dao Ngoc , Lan Huong Nguyen Thi 
Published: November 2020

Abstract
This paper is concerned with the numerical method for the geometrically nonlinear buckling analysis of truss under mechanical load and thermal load due to constant temperature change. The solution of a geometrically nonlinear problem of the system under thermal load based on a displacement-based finite formulation requires the implementation of thermal deformation constraint depending on the incremental element length. The additional constraint of thermal expansion considerably increases the difficulty in finite element formulation and solving method of the nonlinear buckling problem. This research proposes a novel approach to formulate the nonlinear buckling problem of truss under thermal load based on mixed finite formulation. The mixed balanced equation of thermal loading truss considering large displacement is formulated using the principle of virtual work. Based on the formulated equation, the research develops an incremental-iterative algorithm and calculation program for solving the nonlinear buckling problem of thermal loading truss using the arc length technique. The numerical test is presented to investigate the effect of thermal load to buckling behaviour of plan truss.
Finite element analysis of plane frame systems with different models of semi-rigid connections
Authors: Van Tran Thi Thuy , Tung Ngo Dinh , Trung Kien Nguyen 
Published: November 2020

Abstract
Today, in the current Vietnamese design standards for semi-precast reinforced concrete and steel frame structural systems, the connections of main elements such as beams and columns are commonly considered as either perfectly hinged or rigidly fixed. This assumption is adopted because of the simplicity in design and analysis process but it is not consistent with actual behaviour in practice of structural systems. The connections between columns and beams have partial restraint depending on the type of used connection. The analysis of structural system with consideration of the effect of this restraint would result more exactly and economically. However, it is also more time required because of complexity of analysis process with consideration of flexibility of connections in the case of lack of suitable calculation method. The paper presents the analysis of plane frame systems with different of models of semi-rigid connections using finite element method. The analysis process was implemented by MathCad programming software and the results of this study will obtained by conducting of numerical examples. From there the conclusions and recommendation of calculation and design for steel and semi-precast frame systems will be proposed.
Internal resonances in nonlinear fractionally damped plates of the Uflyand-Mindlin type
Authors: Shitikova M V , Osipova E I , Rossikhina E Y 
Published: November 2020

Abstract
In the present paper, the non-linear free vibrations of fractionally damped plates are investigated for the case when its equations of motion involve the rotary inertia and shear deformations via five coupled nonlinear differential equations in terms of three mutually orthogonal displacements and two angles of rotation. The damping features of the surrounding medium are described by the fractional detivative Kelvin-Voigt model. The procedure resulting in decoupling linear parts of governing equations has been proposed, what allows one to utulyze effectively the fractional derivative expansion method for solving the non-linear equations of motion. The occurrence of the internal or combinational resonances has been revealed and classified for plates of the Uflyand-Mindlin type.
Automatic assembly of wind load from BIM-model
Authors: Degtyarev N , Pridvizhkin S , Salnikov V 
Published: November 2020

Abstract
In recent years many Russian construction companies have started using technologies of building information modelling (hereinafter – BIM). It’s a global trend aimed at maximum automation and acceleration of a design process and documentation approval. This article shows main advantages of the BIM approach, discusses the possibility of expanding “the space of benefits” by using digital building models for wind load simulation (automatization of this process). Currently, applied methods of wind impact analysis based on which automation is possible are described. Potential application scenarios, describing the advantages of automatic wind load assembly, are listed. Also, possible approach to the analysis of loads in process of BIM-design is shown.
Bar structures calculation by the method of discrete elements with generalized unknowns in aggressive environments
Authors: Dushko O V , Voronkova G V , Rekunov S S 
Published: November 2020

Abstract
The article considers the application of the method of discrete elements with generalized unknowns for calculating rod systems located in an aggressive environment. The object of research was a spatial rod truss. The basic formulas for determining the reactions of bonds at unit displacements are shown. The equation of displacements for an arbitrary node is derived. The system of equations was solved in partial finite differences. Reactions from external loads were represented as trigonometric series. An algorithm for calculating a statically indeterminate spatial truss by the method of discrete elements with generalized unknowns under the action of an aggressive environment is given. As a result of the calculation, the values of node point movements are obtained.
Search for plastics with piezo optic properties
Authors: Aseyev M A , Tabanykhov K A , Tabanykhova M V 
Published: November 2020

Abstract
The work is devoted to the search for plastics used in 3D printing, which have pronounced piezo optic properties. A review of the works devoted to the study of various characteristics of plastics is performed. It is established that there is currently no data on the piezoelectric properties of consumables for 3D printing. The various brands of plastics widely represented on the market are analyzed. Between them, those that transmit light well were selected. Experimental studies of widely available transparent plastics were performed. The photoelasticity method is used in the work. Several grades of plastics with birefringence have been identified. In the future, it is planned to use these materials for printing models of nodes of spatial structures on a 3D printer in order to obtain stress fields in them.