bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the fracture surface of concretes reinforced with basalt fiber coated with titanium and zirconium dioxides. Fiber-reinforced concrete composites
Authors: Gots V , Berdnyk O , Maystrenko A , Palchik P , Amelina N 
Published: July 2021

Abstract
It is impossible to imagine the development of modern technologies without the use of efficient and affordable fibrous materials based on minerals, glass, and other fibers. The intensive development of the production of fibers and materials based on them worldwide determines the formulation of significant scientific and technical problems of obtaining them with a given set of properties and high-quality indicators, optimization of processing, and rational use. However, the possibility of modifying the composition of the rock with other components that could significantly improve the physical and chemical properties of the fibers is not always taken into account. For the first time, a study was conducted to research the coating of basalt fibers, such as TiO2, ZrO2 and their effect on the physical and chemical characteristics of aluminosilicate melts made from rocks, fiber formation processes, structure, and physical and chemical properties of fibers. Studies have shown that fibers modified with oxides of TiO2 and ZrO2 have higher chemical resistance in aggressive environments compared with unmodified fibers obtained from melts of similar component groups.
Contact heat transfer of a cutting diamond wheel with a boundary layerof air
Authors: Bespalova A , Faizulyna O , Lebedev V , Frolenkova O , Chumachenko T 
Published: July 2021

Abstract
Cutting of natural and artificial building materials is most often carried out with diamond cutting wheels on a metal base at cutting speeds of about 50-80 m/s. The intensity of the cutting process causes a significant heat release, as a result of which the wheel temperature rises to unacceptable values. The value of these unacceptable temperatures is about 600 - 650°C
At these temperatures, graphitization of diamond grains occurs, i.e. loss of diamond layer and loss of cutting properties. In addition, a thin diamond wheel (thickness 1 - 3 mm) is deformed, which leads to jamming and its tensile strength at these temperatures is reduced by half, which creates the risk of rupture by centrifugal forces. In this work, it is taken into account that during the rotation of the wheel, a boundary layer of air is created around it, which is stationary relative to the wheel. Consequently, contact heat transfer occurs between the wheel and the boundary layer, and then convective heat transfer occurs between the boundary layer and the surrounding air. This scheme allows you to more accurately determine the time of safe operation of the diamond wheel. Contact heat transfer between the wheel and the boundary layer is not effective enough to lower the temperature. When air with a negative temperature is introduced into the boundary layer by means of a Rank-Hillsch tube, the wheel temperature decreases by about 10%.
When a sprayed coolant (fog cooling) is introduced into the boundary layer by means of an ejector tube, the wheel temperature decreases by 25%, which ensures an increase in the time of continuous operation.
VIBROABRASIVE TREATMENT OF ULTRA-HARD CERAMICS
Authors: Burlakcov V I , Burlakova G U , Mazur V A , Manoylov O V 
Published: July 2021

Abstract
The article reveals a possibility of treating ultra-hard nitride ceramics by means of vibro-abrasive treatment. It was proved that the value of residua; stresses of the second kind in ceramic samples sufficiently reduced after such treatment. Also it was confirmed experimentally that material removal increased with time. The article contains Difractograms of the surfaces. The surface quality of nitride ceramics was thoroughly analyzed. The grade of abrasive material was determined practically.
The influence of the process-induced deformed state on straightness of prestressing strands after manufacture
Authors: Ozerianskyi B M , Chaiun I M 
Published: July 2021

Abstract
Based on the study of elastic-plastic deformation, the expressions of longitudinal force Nt
, bending Mb
and torque Mt
moments in wire-cross sections subject to the process parameters of rope torsion are obtained: wire tensioning efforts, untwisting and preformation.
A technique for determining the technological internal force factors (TIFF) in the rope cross-sections: the longitudinal forces

N
x
T

(

N

t
i

)

; bending

M
y
T

(

N

t
1

;

M

b
i

;

M

t
i

)
,

M
z
T

(

N

t
i

;

M

b
i

;

M

t
i

)

and torque

M
x
T

(

N

t
i

;

M

b
i

;

M

t
i

)

moments. Being guided by the theorem on unloading and FEM, the external deformed state of the rope unloading from TIFF is studied. The expression of the rope unloading deformations vector

|
D
K
|
=
|
ε
,
θ
,
χ
,
ζ

|
T

as a function of the

F
=
(

N
x
T

;

M
x
T

;

M
y
T

;

M
z
T

)

TIFF vector using the global stiffness matrix of 4×4 rope cross-section corresponding to the elastic deformation is obtained.
Based on the bending deformations, an expression was χ and ζ obtained, the parameter h (h is the segment arrow at the chord length of 1 m), which, according to the regulatory standard, characterizes the degree of the rope straightness after manufacture. The connection between the parameters of torsion (tension, untwisting, and preformation) and the parameter h of straightness is established. It is determined that the unstraightness is directly affected only by the deviation from the uniformity of tension. The developed theory allows to determine the permissible deviation from the non-uniformity of tension with the permissible value of the parameter h of straightness. For example, a prestressing strand of a structure 1+6, having a diameter of 6.9 mm is considered to be of high quality according to the standard, if h ≤ 25mm. This value h corresponds to the deviation of the tension of Δκ = 0,8 one of the 6 wires of the layer. With an increase in deviation of tension, h increases almost rectilinearly to Δκ ≃3. With further increase, a loop is Δκ formed – the loss of stability.
The obtained theory of the external deformed state of unloading provides further opportunity to study the internal deformed-stress state of the rope wires due to process-induced forces, which opens the prospect of even a deeper study of operational strength and durability of ropes.
Effect of alloying elements on structure, metastability and properties of Fe-Cr-Mn (Ni-free) corrosion-resistant austenitic-ferritic steels
Authors: Cheylyakh Y , Cheiliakh A , Kaiming W 
Published: July 2021

Abstract
Investigated was chromium influence within 15-21.4 wt.% and manganese influence within 8-11.4 wt.% upon phase transformations, formation of structure and mechanical properties of corrosion resistant nickel-free (Fe-Cr-Mn) steels of austenite-ferrite structural class. It was found out that by the variation of chromium and manganese content it was possible to modify efficiently the content of ferrite and austenite in the structure, the degree of deformation metastability of austenite and control the mechanical properties of steels. An improved complex of strength, plasticity properties and impact toughness is reached at optimal content of alloying elements (Cr, Mn) in new nickel-free steels, it can be explained by positive impact of deformation induced martensite γ→α’ transformation at testing during their formation.
The use decorative concretes with the addition of highly dispersed chalk for volumetric and spatial elements of urban space
Authors: Chepurna Svitlana , Popova Olha , Ryshchenko Tetiana , Dudka Olena 
Published: July 2021

Abstract
In recent years, the attitude to the external appearance of the urban environment and its elements has changed dramatically. Interest in new constructive solutions, style of urban space design and modern materials which improve the quality of urban space has increased. Installed that the most effective material is decorative concrete, which is used to create a variety of volumetric and spatial elements of engineering improvement, architectural and urban design. The possibility of creating decorative concrete with the addition of highly dispersed chalk and the natural pigment that is distinguished by high operational, decorative, aesthetic properties and solves environmental and economic problems has been considered in the article. The results obtained indicate the possibility of combined use of highly dispersed chalk and yellow natural pigment (ocher) to create colored concrete with high corrosion resistance, frost resistance and decorative and aesthetic properties. The relationship between the durability and corrosion resistance of the test concrete on the size and nature of the pores has been established.
Method for calculating the shape of rolls for helical rolling
Authors: Gorbatyuk S M , Deniskina T V , Balakhnina E E , Chicheneva O N 
Published: July 2021

Abstract
The paper is devoted to solving the problem of determining the shape of the rolls of helical rolling mills, depending on the specified profile of the deformation zone. A universal calculation method has been proposed, thanks to which it is possible to determine the shape of the working surface of a roll for all types of helical rolling mills (with mushroom-shaped, cup-shaped, barrel-shaped and disc rolls), any relative arrangement of the rolling axis and rolls axes, and various locations of the deformation zone on the rolling axis. The proposed method is implemented as a standalone exe-application with a simple intuitive interface. The application allows you to output the calculation results into txt-files, which can then be imported into CAD systems to create 3D roll models.
The problem of plane bending a direct composite beam of arbitrary cross-section and the prerequisites for its approximate analytical solution
Authors: Koval’chuk S B , Goryk O V , Antonets A V 
Published: July 2021

Abstract
The approach to the reduction of the spatial problem of plane bending a composite discrete-inhomogeneous beam of arbitrary cross-section to the approximate two-dimensional bending problem of the equivalent multilayer beam has been discussed here. The result is represented in the form of relations for determination the characteristics of the equivalent multilayer structure by physical and mechanical materials characteristics of the original beam’s phases and the system of static, geometric and physical relations of the corresponding two-dimensional problem. The obtained equations are similar to the plane problem equations of the elasticity theory, but instead of stresses, they contain internal efforts consolidated to the main plane of the beam. The equations of the approximate two-dimensional problem were used to solve the problem of static bending a composite console of arbitrary structure with a load on the free end, taking into account the uniform change of the temperature field. The given system of equations and relations is the starting point for the construction of non-classical deformation models and solving a wide range of problems concerning the deformation of a direct composite beams.
Features of production and application of glued wooden beams in cottage construction
Authors: Guzii S G 
Published: July 2021

Abstract
This paper discusses the technological features of the production and use of laminated veneer lumber in cottage construction. The main properties of aluminosilicate glue for gluing pine lamellas have been determined. Changes in both the dynamic and plastic viscosity of aluminosilicate glue are given depending on the spindle rotation speed and shear rate. Equations describing these dependencies are given. These dependencies influence the choice of the method for applying the aluminosilicate glue to the substrate surface. It has been shown that a change in dynamic viscosity from 1662 to 1268 cP in the operating speed range from 20 to 30 RPM and shear rate from 4.2 to 6.3 1/s provides a small shear force from 69.9 to 79.88 dynes/cm2, which makes it easy to apply the glue with a brush or a special roller.
It is noted that aluminosilicate glue with a density of 1.54 g/cm3 has a low surface tension of 54 mN/m, which affects the contact angle and the tendency to spread on a pine base. It has been found that an increase in the spreading coefficient results in more complete wetting. It is shown that with an increase in the curing time of the glue joints, the shear strength along the fibers and the elastic modulus on the 28th day increase by 1.63/1.1 times as compared with the seven-day age. An increase in strength and elastic modulus is associated with the passage of crystallization processes in an aluminosilicate gel with the subsequent formation of zeolite-like formations. It is noted that the increase in the value of the breaking load of the samples at the age of 28 days is 1.63 times higher than after 7 days of curing, for determining the values of the shear modulus and elasticity does not have such a decisive importance and this decrease is 5.1%.
Application of parallel computing in finite element analysis of constructions
Authors: Homenyk S I , Kozub V Yu 
Published: July 2021

Abstract
To optimize finite elements computational processes of the “MIRELA +” computing complex, parallel programming algorithms have been developed for creating stiffness matrices of finite elements and calculating the stress-strain. The parallel data processing is implemented using OpenMP library. On the basis of computational methods of experiments, the use of parallel computing algorithms at the beginning of solving problems with traditional finite element algorithms for large-dimensional grids has been established.
Effect of critical speed in machining of the main shaft of cone crushers on accuracy of treated surfaces
Authors: Kondratenko V E , Devyatiarova V V , Sedykh L V , Madgoziev F U 
Published: July 2021

Abstract
One of the industry development factors is the advancement of design and technological solutions of production applications. Mining industry makes heavy use of cone crushers, with the main shaft being one of the main components under serious loads, thus requiring repair or replacement. The paper suggests the method to determine the critical speed of the main shaft of cone crushers in machining and the effect, which the type of fixing on metal-cutting machines has on the accuracy of its surfaces.
Study of Stress-Strain Behavior of the Laminated Plate Damaged by Delamination
Authors: Kondratiev A , Smovziuk L , Shevtsova M , Nabokina T , Tsaritsynskyi A 
Published: July 2021

Abstract
The process of manufacturing of the structures of polymeric composite materials is accompanied by various technological defects. Delamination defects have the greatest impact on the bearing capacity of the composite structures. The method for assessment of the stress-strain behavior of a panel structure made of polymeric composite materials, which is damaged by delamination, has been developed. This method allows determining the degree of stress concentration in the area of step change in thickness and identifying the most dangerous point where the structural failure may start. In contrast to the classical theory of laminated plates, the proposed model gives an opportunity to simplify three-dimensional problem by setting the displacement field on the interfaces of layers and their linear interpolation over the plate thickness, taking into account the transverse shear deformation. Stress-strain behavior of the plate with delamination was determined according to the computational model of the plate with a cut for the case when the layers in the defect area cannot take up the applied load. According to the results obtained, distribution of stresses over the plate thickness changes significantly in the area of step transition to the delamination and near it. At the distance, it approaches the stress distribution in a plate of the uniform thickness. It allowed confirming the previous conclusions that maximum rise in stresses may occur in the weakened layer near the delamination, initiating the failure of the structure. Reliability of the developed mathematical model is confirmed by comparison with the results of experimental studies. The resulting maximum error does not exceed 7% and demonstrates good convergence of results. With the use of the developed method, it is possible to solve the important practical tasks of studying the loss of performance of the panel structures made of polymeric composite materials with delaminations and determining the optimal methods for repair of such defects.
An analytical solution to the problem of thermoelastic bending of a multilayer beam with different temperature of longitudinal faces
Authors: Koval’chuk S B , Goryk O V 
Published: July 2021

Abstract
An exact analytical solution of the quasistatic problem of thermoelasticity is presented for a section of a narrow multilayer beam with different temperatures of the longitudinal lower and upper faces and a heat flow of arbitrary height across the sections through the lateral faces. The solution was obtained for the entire package of layers by sequentially solving the heat equation for an inhomogeneous beam, taking into account the ideal thermal contact of the layers and the system of equations of the plane problem of the theory of elasticity under the assumption of a rigid connection of the layers. To take into account the inhomogeneity of the beam, a continuum approach is used, in which the multilayer material is considered continuous with variable physical and mechanical characteristics. The resulting relations take into account the orthotropy of the physico-mechanical properties of the materials of the layers and their compliance with the transverse shear and compression strains. An example of implementation of a solution for a five-layer beam with combined rigid and articulated fastening of the ends is given.
Stress-strain state of elastomeric vibroseismic insulators
Authors: Kozub Yu G , Dyrda V I , Kozub G A 
Published: July 2021

Abstract
A method for solving problems of viscoelastic deformation of structures made of weakly-compressible elastomers, based on the application of the hereditary Boltzmann-Volterra theory, is considered. To consider the weak compressibility and eliminate the “false shift” effect, the moment scheme of the finite element is used.
Modeling of Transformation of Quality Indicators in the Process of Mechanical Processing of Products with High Physical and Mechanical Properties
Authors: Parshyna Olena , Parshyna Marharyta , Parshyn Yurii , Gurenko Anna , Savchenko Iurii , Shapoval Alexander 
Published: July 2021

Abstract
Complex technologies are technologies which consist of a certain set of stages and technological processes. Using the theoretical basis of the systemic and synergetic approaches, the technological process of manufacturing of such parts has been represented as a process of qualitative and quantitative changes of the object. Taking into account the phenomena of technological heredity, it has been assumed that physical and mechanical properties, in particular, tensile strength, proportionality limit, relative narrowing and resilience, as well as characteristics of the quality of the treated surfaces and processing accuracy can be transformed during the complex technological process. To describe the transformation processes of quality indicators, a set of experimental studies of the roughness of the treated surface during machining of parts with high physical and mechanical properties has been carried out and mathematical models have been obtained. To determine the conditions of the integrated technology, it has been proposed to use a complex of dimensionless characteristics - relative changes of the coefficients of the mathematical model. The obtained mathematical models of the processes of mechanical treating of steel 38HN3MFA make it possible to determine the processing conditions that ensure the formation of a given set of quality indicators.
Features of the structure formation processes and synthesis of strength for Portland cement compositions modified with nanocarbonate additives
Authors: Pushkarova K. , Hadaichuk D. , Honchar O. , Kushnierova L , Кaverin К. , Ionov D. 
Published: July 2021

Abstract
The work shows the results of studying the features of the structure formation process when nano-carbonate additives of different physical states are added to Portland cement and the establishment of the appropriate technology for their introduction, which provides the best conditions for the synthesis of artificial stone. It was found that the introduction of nanocarbonate additives in the form of dispersion provides better kinetics of the cement stone strength gain, and the effect of the introduction of dispersion exceeds the effect of the introduction of powder on 7th day by (43 … 48)%, on 28th day - (27… 30)% and 365th day by (25… 29)%. The using of the dispersion is more economically efficient, while preventing the aggregation of particles provides a directed synthesis of crystal-chemically similar compounds. The nanocarbonate additive acts as a substrate for the directional formation of hydrosilicate phases, providing microreinforcement and the formation of a more homogeneous and improved structure of artificial stone at both nano- and micro-levels.
Restriction of Cl- and SO4
2- Ions Transport in Alkali Activated Slag Cement Concrete in Seawater
Authors: Kryvenko P , Rudenko I , Konstantynovskyi O , Boiko O 
Published: July 2021

Abstract
The relevance of alkali activated slag cement (AASC) concretes for structures operated in seawater is due to their enhanced resistance in aggressive environments. The application of high consistency fresh concretes is accompanied by negative changes in their structure with higher penetration of aggressive environments. Thus, the methods to prevent corrosion of steel reinforcement in plasticized AASC concrete are actual for investigations. It is shown, that modification of plasticized AASC concrete (consistency class S4) by the complex «alumina cement - portland cement - clinoptilolite - trisodium phosphate (Na3PO4·12H2O)» restrict the transport of aggressive Cl- and SO4
2- ions. The results of DTA, XRD, electron microscopy, microzond analysis show that mentioned complex limits transport of the mentioned aggressive ions due to their binding by AFm phases in hydration products, exchange with OH- ions in the structure of clinoptilolite, formation of hydrated products of apatite group Ca5(PO4)3(OH, Cl). This was confirmed by qualitative reaction on Cl- and SO4
2- ions in concrete structure, as well as by assessing of surface and mass loss of steel bars embedded in AASC concrete after 9 months in seawater. It was ensured the advanced crystallization with densification of microstructure, which increases corrosion resistance of artificial stone.
To the problem of transverse anisotropy effect on the distribution of contact stresses in a beam-strip loaded with a rigid stamp
Authors: Shvabiuk V.I , Rotko S.V. , Svabiuk V.V. , Hryshkova A.V. 
Published: July 2021

Abstract
The contact interaction of an orthotropic bar-beam loaded with a rigid stamp. The nature of contact stresses distribution along contact surface of beam and the size of the contact region depending on the beam material orthotropy degree is studied. Analytical expressions for contact pressure under the stamp, dimensionless force, size of contact region and stamp settlement depending on contact region size are derived. Numerical results of calculations are given.