Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-184-192
L. Lyakhovich, P. Akimov
For some elastic systems with a finite number of degrees of freedom of masses, in which the directions of mass movement are parallel and lie in the same plane (for example, rods), special methods have been developed for creating additional constraints, the introduction of each of which purposefully increases the value of only one natural frequency and does not change any from the natural modes. The method of forming a matrix of additional stiffness coefficients that characterize such targeted constraint in this problem can also be applied when solving a similar problem for elastic systems with a finite number of degrees of mass freedom, in which the directions of mass movement are parallel, but do not lie in the same plane (for example, plates). At the same time, for such systems, only the requirements for the design schemes of additional targeted constraints are formulated, and not the methods for their creation. The distinctive paper proposes an approach that allows researcher to create computational schemes for additional targeted constraints for such systems. A variant of the computational scheme, represented by a rod system with one degree of activity, is considered. Some special properties of such targeted constraints are revealed. When forming the computational scheme, the material consumption for creating a constraint is minimized, and design restrictions are taken into account. Particular attention is paid to the modification of the computational scheme of the constraint, when, during its formation, rods appear that “pass” through the original system.
{"title":"FORMATION OF COMPUTATIONAL SCHEMES OF ADDITIONAL TARGETED CONSTRAINTS THAT REGULATE THE FREQUENCY SPECTRUM OF NATURAL OSCILLATIONS OF ELASTIC SYSTEMS WITH A FINITE NUMBER OF DEGREES OF MASS FREEDOM, THE DIRECTIONS OF MOVEMENT OF WHICH ARE PARALLEL, BUT D","authors":"L. Lyakhovich, P. Akimov","doi":"10.22337/2587-9618-2022-18-2-184-192","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-184-192","url":null,"abstract":"For some elastic systems with a finite number of degrees of freedom of masses, in which the directions of mass movement are parallel and lie in the same plane (for example, rods), special methods have been developed for creating additional constraints, the introduction of each of which purposefully increases the value of only one natural frequency and does not change any from the natural modes. The method of forming a matrix of additional stiffness coefficients that characterize such targeted constraint in this problem can also be applied when solving a similar problem for elastic systems with a finite number of degrees of mass freedom, in which the directions of mass movement are parallel, but do not lie in the same plane (for example, plates). At the same time, for such systems, only the requirements for the design schemes of additional targeted constraints are formulated, and not the methods for their creation. The distinctive paper proposes an approach that allows researcher to create computational schemes for additional targeted constraints for such systems. A variant of the computational scheme, represented by a rod system with one degree of activity, is considered. Some special properties of such targeted constraints are revealed. When forming the computational scheme, the material consumption for creating a constraint is minimized, and design restrictions are taken into account. Particular attention is paid to the modification of the computational scheme of the constraint, when, during its formation, rods appear that “pass” through the original system.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77458973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-14-30
V. Travush, V. Kolchunov, S. Bulkin, M. Protchenko
Despite a fairly long period of research and a significant number of publications around the world on the problem of the complex resistance of reinforced concrete, the existing calculation models still remain far from perfect. This is especially true for structures with a non-rectangular cross section. The article presents a version of the model and an algorithm for the analytical calculation of reinforced concrete structures of a circular cross section in torsion with bending, which most fully reflects the specifics of the power resistance of such structures. The model takes into account all the components of external forces in a rod element of a circular cross section, the spatial nature of cracks, with the combined action of moments, various cases of the location of the compressed concrete zone, depending on the ratio of the acting forces in the calculated structure. For a spatial crack, calculated sections are taken in the form of diagonal large and small ellipses and a spatial surface bounded by concave and convex spatial parabolas. In compressed and stretched concrete, a broken section of three sections is considered, two in the form of longitudinal trapezoid and the third, middle section in the form of a small ellipse rotated at an angle to the longitudinal axis of the structure. The obtained analytical dependencies allow one to determine interconnected design parameters, such as stresses in the concrete of the compressed zone, the height of the compressed concrete, stresses in the longitudinal and transverse reinforcement, deformations in concrete and reinforcement, the length of the projection of a spatial inclined crack, and others. The deformation model and algorithm can be used in the design of reinforced concrete structures of circular and annular cross-section, working in bending with torsion.
{"title":"DEFORMATION MODEL AND ALGORITHM FOR CALCULATION OF REINFORCED CONCRETE STRUCTURES OF ROUND CROSS-SECTION UNDER TORSION WITH BENDING","authors":"V. Travush, V. Kolchunov, S. Bulkin, M. Protchenko","doi":"10.22337/2587-9618-2022-18-2-14-30","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-14-30","url":null,"abstract":"Despite a fairly long period of research and a significant number of publications around the world on the problem of the complex resistance of reinforced concrete, the existing calculation models still remain far from perfect. This is especially true for structures with a non-rectangular cross section. The article presents a version of the model and an algorithm for the analytical calculation of reinforced concrete structures of a circular cross section in torsion with bending, which most fully reflects the specifics of the power resistance of such structures. The model takes into account all the components of external forces in a rod element of a circular cross section, the spatial nature of cracks, with the combined action of moments, various cases of the location of the compressed concrete zone, depending on the ratio of the acting forces in the calculated structure. For a spatial crack, calculated sections are taken in the form of diagonal large and small ellipses and a spatial surface bounded by concave and convex spatial parabolas. In compressed and stretched concrete, a broken section of three sections is considered, two in the form of longitudinal trapezoid and the third, middle section in the form of a small ellipse rotated at an angle to the longitudinal axis of the structure. The obtained analytical dependencies allow one to determine interconnected design parameters, such as stresses in the concrete of the compressed zone, the height of the compressed concrete, stresses in the longitudinal and transverse reinforcement, deformations in concrete and reinforcement, the length of the projection of a spatial inclined crack, and others. The deformation model and algorithm can be used in the design of reinforced concrete structures of circular and annular cross-section, working in bending with torsion.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90450619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-156-162
V. Kats, L. Adamtsevich
Technical diagnostics of facilities is an urgent problem during its operation. An integral part of the implementation of diagnostic monitoring systems is the development of a decision support system (DSS) based on the analysis of acoustic emission (AE) diagnostic data and machine learning methods. A necessary condition for the application of machine learning methods in the development of DSS is the process of extracting diagnostic features from the AE signal. In the present work, an improved method is proposed for extracting diagnostic features from time series of AE signals. This includes two successive steps. At the first step, the frequency and frequency-time characteristics are calculated in a sliding window of short duration, which describe local changes in the shape and structure of single pulses. At the second step, the resulting matrix of informative features is aggregated by calculating statistical moments of various orders, which makes it possible to effectively detect long-term trends in the AE signal changes emitted by the defect. Verification of the proposed method was carried out on a full-scale control object of the oil tank RVS No. 3 ("NTEK LLC"). Based on the results obtained, a conclusion was made about the effectiveness of the proposed method in the development of diagnostic monitoring systems based on acoustic emission data.
{"title":"METHOD FOR EXTRACTING DIAGNOSTIC FEATURES OF THE FACILITIES TECHNICAL CONDITION IN THE SYSTEM FOR MONITORING","authors":"V. Kats, L. Adamtsevich","doi":"10.22337/2587-9618-2022-18-2-156-162","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-156-162","url":null,"abstract":"Technical diagnostics of facilities is an urgent problem during its operation. An integral part of the implementation of diagnostic monitoring systems is the development of a decision support system (DSS) based on the analysis of acoustic emission (AE) diagnostic data and machine learning methods. A necessary condition for the application of machine learning methods in the development of DSS is the process of extracting diagnostic features from the AE signal. In the present work, an improved method is proposed for extracting diagnostic features from time series of AE signals. This includes two successive steps. At the first step, the frequency and frequency-time characteristics are calculated in a sliding window of short duration, which describe local changes in the shape and structure of single pulses. At the second step, the resulting matrix of informative features is aggregated by calculating statistical moments of various orders, which makes it possible to effectively detect long-term trends in the AE signal changes emitted by the defect. Verification of the proposed method was carried out on a full-scale control object of the oil tank RVS No. 3 (\"NTEK LLC\"). Based on the results obtained, a conclusion was made about the effectiveness of the proposed method in the development of diagnostic monitoring systems based on acoustic emission data.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88883052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-62-73
Vu Dinh Tho, E. Korol, V. Rimshin, P. Anh
The object of the study is multi-layer reinforced concrete structures of concrete with various physical and mechanical characteristics of materials - concrete and reinforcement under the influence of loading. Analysis of the stress state of multilayer reinforced concrete beams by using different materials is a complex problem due to the different mechanical and physical characteristics of materials and the cracking behavior of concrete. This article presents an analysis of the stress-strain state of three-layered reinforced concrete structures using the finite element method in the program ANSYS Mechanical. Numerical modeling allows on ANSYS allows combining different combinations of loads, the variability of the strength and deformation characteristics of materials and various types of reinforcement in multilayer reinforced concrete beams. Comparison is made between the experimental results, numerical results and finite element analyses with respect to initial crack formation and the ultimate load capacity of beams. The results of the study were shown that as the grade of concrete in the external layer increases from B15 to B20 and the grade of lightweight concrete in the internal layer increases from B0.75 to B1.5, the crack resistance can be increased by 59.7% and the bearing capacity of the test beam is increased by 16.4%. When the thickness of the external layers varies from 40mm to 80mm, making the crack resistance increased by 47.5% and the bearing capacity of three-layer concrete beams greatly increased by 6.7%. The obtained scientific results enable to determine rational parameters for modeling various structural solutions of multilayer reinforced concrete structures.
{"title":"MODEL OF STRESS-STRAIN STATE OF THREE-LAYERED REINFORCED CONCRETE STRUCTURE BY THE FINITE ELEMENT METHODS","authors":"Vu Dinh Tho, E. Korol, V. Rimshin, P. Anh","doi":"10.22337/2587-9618-2022-18-2-62-73","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-62-73","url":null,"abstract":"The object of the study is multi-layer reinforced concrete structures of concrete with various physical and mechanical characteristics of materials - concrete and reinforcement under the influence of loading. Analysis of the stress state of multilayer reinforced concrete beams by using different materials is a complex problem due to the different mechanical and physical characteristics of materials and the cracking behavior of concrete. This article presents an analysis of the stress-strain state of three-layered reinforced concrete structures using the finite element method in the program ANSYS Mechanical. Numerical modeling allows on ANSYS allows combining different combinations of loads, the variability of the strength and deformation characteristics of materials and various types of reinforcement in multilayer reinforced concrete beams. Comparison is made between the experimental results, numerical results and finite element analyses with respect to initial crack formation and the ultimate load capacity of beams. The results of the study were shown that as the grade of concrete in the external layer increases from B15 to B20 and the grade of lightweight concrete in the internal layer increases from B0.75 to B1.5, the crack resistance can be increased by 59.7% and the bearing capacity of the test beam is increased by 16.4%. When the thickness of the external layers varies from 40mm to 80mm, making the crack resistance increased by 47.5% and the bearing capacity of three-layer concrete beams greatly increased by 6.7%. The obtained scientific results enable to determine rational parameters for modeling various structural solutions of multilayer reinforced concrete structures.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77726201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-51-61
Awwad Talal, Alkayyal Hassan
In this paper, a dynamic shear strength analysis was performed in a finite elements environment to evaluate the stability of embankments under seismic loadings. In addition, a dynamic factor of safety depending on the results of the numerical analysis was defined. To study these parameters' effects on the embankment's stability, a parametric study concerning the embankment inclination and the soil type was performed. Finally, the numerical analysis results were compared with the results of the pseudo-static analysis according to the EC8. The results of this study show the significance of the numerical seismic analyses in comparison with the analytical calculations.
{"title":"SEISMIC DESIGN OF EMBANKMENTS - NUMERICAL AND ANALYTICAL STUDY","authors":"Awwad Talal, Alkayyal Hassan","doi":"10.22337/2587-9618-2022-18-2-51-61","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-51-61","url":null,"abstract":"In this paper, a dynamic shear strength analysis was performed in a finite elements environment to evaluate the stability of embankments under seismic loadings. In addition, a dynamic factor of safety depending on the results of the numerical analysis was defined. To study these parameters' effects on the embankment's stability, a parametric study concerning the embankment inclination and the soil type was performed. Finally, the numerical analysis results were compared with the results of the pseudo-static analysis according to the EC8. The results of this study show the significance of the numerical seismic analyses in comparison with the analytical calculations.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91190629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-112-120
S. Kosytsyn, V. Akulich
А study was carried out on influence of stage-by-stage construction of a cylindrical shell on stress-strain states of an existing nearby shell in a soil body. Additionally, a case is considered in which the stage-by-stage construction of shells was not taken into account. The obtained results were analyzed by the authors
{"title":"INFLUENCE OF STAGE-BY-STAGE CONSTRUCTION OF A CYLINDRICAL SHELL ON STRESS-STRAIN STATES OF AN EXISTING NEARBY SHELL IN A SOIL BODY","authors":"S. Kosytsyn, V. Akulich","doi":"10.22337/2587-9618-2022-18-2-112-120","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-112-120","url":null,"abstract":"А study was carried out on influence of stage-by-stage construction of a cylindrical shell on stress-strain states of an existing nearby shell in a soil body. Additionally, a case is considered in which the stage-by-stage construction of shells was not taken into account. The obtained results were analyzed by the authors","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"96 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74151598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-175-183
Igor M. Bezgodov, S. Kaprielov, A. Sheynfeld
he paper provides data on the strength and deformation characteristics of heavy self-compacting concrete of classes B30-B100 with a cubic compressive strength of 36.5-114.8 MPa. It has been established that the values of the concrete prism compressive strength (36.2-104.2 MPa) are 42-64% higher than the normalized values given in the building code of the Russian Federation SP 63.13330.2018. The values of the static modulus of elasticity for high-strength concretes of classes B80-B100 are 44.1-48.1 GPa and exceed by 5-12% the values given in SP 63.13330.2018. The ultimate compressive strains of concrete of classes B30-B100 are in the range from 261×10-5 to 326×10-5 and exceed the value of 200×10-5 given in SP 63.13330.2018. Complete deformation diagrams of self-compacting concretes of classes B30-B100 have been constructed. The nonlinearity of these ones decreases with increasing concrete strength. The descending branch of the σ-ε diagram is observed only for concrete of a class below B55 with a total relative compres-sive strain of 403.3 × 10-5 under a loading level of 0.85Rb. Concrete of classes B55-B100 has no descending branch. Previously established dependencies are refined for the analytical description of strains and stresses at any stages of loading structures.
{"title":"RELATIONSHIP BETWEEN STRENGTH AND DEFORMATION CHARACTERISTICS OF HIGH-STRENGTH SELF-COMPACTING CON-CRETE","authors":"Igor M. Bezgodov, S. Kaprielov, A. Sheynfeld","doi":"10.22337/2587-9618-2022-18-2-175-183","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-175-183","url":null,"abstract":"he paper provides data on the strength and deformation characteristics of heavy self-compacting concrete of classes B30-B100 with a cubic compressive strength of 36.5-114.8 MPa. It has been established that the values of the concrete prism compressive strength (36.2-104.2 MPa) are 42-64% higher than the normalized values given in the building code of the Russian Federation SP 63.13330.2018. The values of the static modulus of elasticity for high-strength concretes of classes B80-B100 are 44.1-48.1 GPa and exceed by 5-12% the values given in SP 63.13330.2018. The ultimate compressive strains of concrete of classes B30-B100 are in the range from 261×10-5 to 326×10-5 and exceed the value of 200×10-5 given in SP 63.13330.2018. Complete deformation diagrams of self-compacting concretes of classes B30-B100 have been constructed. The nonlinearity of these ones decreases with increasing concrete strength. The descending branch of the σ-ε diagram is observed only for concrete of a class below B55 with a total relative compres-sive strain of 403.3 × 10-5 under a loading level of 0.85Rb. Concrete of classes B55-B100 has no descending branch. Previously established dependencies are refined for the analytical description of strains and stresses at any stages of loading structures.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77386218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-121-130
Aleksander Treshchev, Violetta Kuznetsova
In this paper, a mathematical model is considered that allows one to determine the stress-strain state of a spherical shell made of titanium alloy VT1-0, the external load is assumed to be transverse uniformly distributed, acting on the outer surface, the medium is assumed to act on the inner surface of the shell. For this, a nonlinear model was used, presented in normalized stress spaces. Fastening along the contour of the shell is rigid. Nonlinear resolving equations for calculating a spherical shell are obtained. An algorithm for solving the problem of hydrogenation of titanium alloy shells has been developed. A practical solution was made by a two-step method of sequential perturbations of parameters using the MatLab and Maple software packages. To solve the system of the obtained differential equations, the method of finite differences is applied. The calculation of the stress-strain state of the shell is obtained taking into account the diffusion process of an aggressive hydrogen-containing medium, and the obtained solution is compared with the results of the classical nonlinear theory without taking into account the aggressive medium. The results of comparing these solutions demonstrate quantitative differences in the parameters of the shell deformation process, which are explained by a more accurate account of the influence of the type of stress state. This approach has a rather flexible mechanism for considering the initial and induced differential resistance, demonstrates a high accuracy of matching the obtained theoretical results with empirical data on loading a wide range of materials under complex types of stress state.
{"title":"STUDY OF THE INFLUENCE OF THE KINETICS OF HYDROGEN SATURATION ON THE STRESS-DEFORMED STATE OF A SPHERICAL SHELL MADE FROM TITANIUM ALLOY","authors":"Aleksander Treshchev, Violetta Kuznetsova","doi":"10.22337/2587-9618-2022-18-2-121-130","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-121-130","url":null,"abstract":"In this paper, a mathematical model is considered that allows one to determine the stress-strain state of a spherical shell made of titanium alloy VT1-0, the external load is assumed to be transverse uniformly distributed, acting on the outer surface, the medium is assumed to act on the inner surface of the shell. For this, a nonlinear model was used, presented in normalized stress spaces. Fastening along the contour of the shell is rigid. Nonlinear resolving equations for calculating a spherical shell are obtained. An algorithm for solving the problem of hydrogenation of titanium alloy shells has been developed. A practical solution was made by a two-step method of sequential perturbations of parameters using the MatLab and Maple software packages. To solve the system of the obtained differential equations, the method of finite differences is applied. The calculation of the stress-strain state of the shell is obtained taking into account the diffusion process of an aggressive hydrogen-containing medium, and the obtained solution is compared with the results of the classical nonlinear theory without taking into account the aggressive medium. The results of comparing these solutions demonstrate quantitative differences in the parameters of the shell deformation process, which are explained by a more accurate account of the influence of the type of stress state. This approach has a rather flexible mechanism for considering the initial and induced differential resistance, demonstrates a high accuracy of matching the obtained theoretical results with empirical data on loading a wide range of materials under complex types of stress state.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83583025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-74-84
O. Burtseva, V. Kohanenko, S. Evtushenko, M. Alexandrova
The article considers the free spreading of a turbulent stationary two-dimensional open potential water flow into a wide diverting riverbed behind a non-pressure pipe of a rectangular section. A system of nonlinear partial differential equations of motion has been adopted as the mathematical model of the flow in the physical plane. When moving to the plane of the velocity hodograph, the nonlinear system of equations is transformed into a linear system with respect to partial derivatives. Using the obtained system of equations, various problems along the flow of two-dimensional water streams have been solved analytically. The paper determines the flow kinetics parameter t and the angle q characterizing the direction of the local flow velocity vector at the intersection points of an arbitrary equipotential and an arbitrary current line. The X, Y coordinates of these points are found. The peculiarities of changing the angle θ during the transition of the vertical front of the XD are taken into account. Article proposes a module for the transition from a two-dimensional water flow model to a one-dimensional one. This module is necessary for using the laws of flow resistance and taking into account the resistance forces. The model proposed in this paper is a development of analytical methods for calculating potential flows with previously unknown boundaries and before the flow expands. It allows determining the entire range of geometric and kinematic parameters of the flow with an error not exceeding 10%. The adequacy of the model for all flow parameters improves the accuracy of previously existing methods. This allows the designers of road culverts to increase its reliability.
{"title":"THE MODEL OF FREE SPREADING A FLOW RAPID BEHIND A RECTANGULAR PIPE","authors":"O. Burtseva, V. Kohanenko, S. Evtushenko, M. Alexandrova","doi":"10.22337/2587-9618-2022-18-2-74-84","DOIUrl":"https://doi.org/10.22337/2587-9618-2022-18-2-74-84","url":null,"abstract":"The article considers the free spreading of a turbulent stationary two-dimensional open potential water flow into a wide diverting riverbed behind a non-pressure pipe of a rectangular section. A system of nonlinear partial differential equations of motion has been adopted as the mathematical model of the flow in the physical plane. When moving to the plane of the velocity hodograph, the nonlinear system of equations is transformed into a linear system with respect to partial derivatives. Using the obtained system of equations, various problems along the flow of two-dimensional water streams have been solved analytically. The paper determines the flow kinetics parameter t and the angle q characterizing the direction of the local flow velocity vector at the intersection points of an arbitrary equipotential and an arbitrary current line. The X, Y coordinates of these points are found. The peculiarities of changing the angle θ during the transition of the vertical front of the XD are taken into account. \u0000Article proposes a module for the transition from a two-dimensional water flow model to a one-dimensional one. This module is necessary for using the laws of flow resistance and taking into account the resistance forces. \u0000The model proposed in this paper is a development of analytical methods for calculating potential flows with previously unknown boundaries and before the flow expands. It allows determining the entire range of geometric and kinematic parameters of the flow with an error not exceeding 10%. \u0000The adequacy of the model for all flow parameters improves the accuracy of previously existing methods. This allows the designers of road culverts to increase its reliability.","PeriodicalId":36116,"journal":{"name":"International Journal for Computational Civil and Structural Engineering","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88542351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.22337/2587-9618-2022-18-2-43-50
A. Zhussupbekov, A. Yessentayev, Viktor Kaliakin, I. Drozdova
A comparative analysis of the results of field tests to determine the bearing capacity of a pile at the facilitys in the Nur-Sultan city and Petropavlovsk city. The aim of the study was to carry out a comparative analysis of the results of dynamic and static tests in the two construction site in order to identify the difference in performance. This article provides programs and results of tests with static indentation load and dynamic load on a pile in different two of the construction site under different soil conditions. The results of the comparative analysis are the following: Dynamic tests are needed for a preliminary assessment of the dynamic bearing capacity and the possibility of driving piles in different soil conditions. The bearing capacity of the pile, determined by dynamic tests, is slightly lower than during static tests, the difference between the results is 11 and 17%.
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