Indentation is a universal and practical method for obtaining material characteristics, especially when it is impossible or difficult to expose the material to other measuring methods. Experimental data on the mechanical properties of various types of materials were obtained using the shock loading unit. A mathematical model based on the finite element method was used to verify the experimental results. The article considers the solution of the problem of classification of neural metals with different mechanical properties. As part of the work, an artificial neural network has been created that allows the distribution of materials into selected groups. It is determined that a significant advantage of using neural networks is the ability to process experimental data and identify complex nonlinear dependencies, which makes them in demand in tasks related to the study of material properties.
Keywords: impact indentation, neural network, task of classification, artificial intelligence, dynamic indentation, non-destructive testing.
The public education project ""Dream School"", implemented in support of the federal school overhaul program, attracts students of architectural and design schools in the regions, which will allow them to simultaneously acquire applied competencies in the learning process. During the development of the design project, the need for specialists to conduct a preliminary design analysis was revealed, since one of the five schools did not meet the standards in terms of their spatial planning parameters. It is proposed to carry out the reconstruction of this educational institution. The premises of the dining room and the assembly hall are transferred to the annex block.
Keywords: school design project, school renovation, school recreation, public education project "Dream School", school reconstruction
In the paper, parametric equations of right conoidal surfaces with an orthogonal coordinate system with different guiding curves are obtained for the first time. Parametric equations for conoids with guide curves sine, cosine and parabola are presented. In the MathCad system, the constructions of right conoids with selected guide curves with various initial geometric parameters are visually performed and presented in the paper for the possibility of expanding their use in architectural design, construction and other industries.
Keywords: conoid, orthogonal coordinate system, sine, cosine, parabola, parametric equation, MathCad system
The article discusses the design features of wooden buildings constructed from cross laminated timber panels (CLT). CLTis a new material widely used in wooden house construction. The panels are used for the construction of multi-storey buildings and replace traditional frame and cobblestone wooden houses. The article analyzes the advantages of using CLT in modern construction, discusses various types of joints, such as butt joints, corner joints, as well as their advantages and disadvantages. Special attention is paid to panel mounting methods that ensure the reliability and durability of the structure.
Keywords: wooden structure, wood, cross-laminated timber, CLT panel, nodal connection, connection system
The article presents calculations of energy costs when carrying out major renovations of a building. Based on the obtained values, the structure of fuel and energy resources expenditures by subgroups of repair and construction work was formed. The presented research results are based on the calculation and comparison of the obtained energy consumption values in proportional units - kilograms of standard fuel. As a result of the study, the highest energy consumption was established, which is accounted for by the consumption of liquid fuel in comparison with electricity, which is due to the specifics of the machines and mechanisms used (truck crane, truck, etc.), as well as the chosen technology of repair and construction work. In order to account for and minimize energy costs during the period of major repairs, it is also proposed to monitor the consumption of fuel and energy resources.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
Paper presents an algorithm for analyzing and controlling data and project quality in construction using building information modeling and extensible markup language. The authors, argue that project quality stems from data quality and information quality. The proposed algorithm integrates BIM with extensible markup language, converting data quality and project quality criteria from employer information requirements into an extensible markup language scheme to ensure compliance with established standards. Key criteria for data quality and project quality include classification, identity, hierarchy, information identity, coordination, level of development , association, redundancy, staging, and spatial orientation. The algorithm involves creating a test BIM model, to simulate employer information requirements violations, performing checks using a Model Checker, automation tool in Autodesk Revit, and ensuring all criteria are met. The process includes saving verification checks, combining them, and generating reports in comma separated values format for transparency and further analysis. The authors highlight the importance of applying the algorithm from the early stages of project discussions, involving all participants to ensure the accuracy of data quality and project quality schemes. This approach leverages both international and domestic standards for continuous monitoring and immediate decision-making support throughout the project lifecycle.
Keywords: extensible markup language, information technical requirements, employer information requirements, building information model, information quality, project quality, model checking
The article is devoted to the study of the main methods of ice crossings and their reinforcement. Key concepts related to this type of transportation are considered, including the definition of an ice crossing, its role in the transportation infrastructure, and the conditions necessary for its construction. Special attention is paid to the preparatory work carried out in summer and the main work carried out in winter. The methods of ice crossing reinforcement are described in detail, including thermal reinforcement, use of logs, snow reinforcement and use of geosynthetic materials. The advantages and disadvantages of each method are discussed, as well as factors influencing the choice of a particular reinforcement method.
Keywords: ice crossing, reinforcement
The article contains the methodology and results of theoretical and experimental studies of the stress-strain state of a conical radial-beam dome with triangular shell elements. The results obtained by various methods are analyzed and compared. The triangular membrane panel is part of the radial beam dome structure and consists of a support frame and a steel membrane in the shape of a triangle. The shape of the triangle forming the membrane panel can be different and depends on the number of ribs in the radial beam dome. The supporting contour is a compressed-bending element of the dome and is made, as a rule, from a rolled steel profile with a channel section. The membrane is made of thin steel sheet and attached to the upper flange of the channel with self-tapping screws or spot welding. To assess the strength and deformability of a steel membrane sheet, its operation under the action of a uniformly distributed snow load, an unevenly distributed snow load and a concentrated installation load was considered. Several options for nonlinear static calculations in various computer systems are shown.
Keywords: building structures, wooden structures, membrane panel, stress-strain state, radial beam dome, dome, membrane, design, experimental study
The object of study is flexural reinforced concrete elements without transverse reinforcement under the action of shear forces. The calculation of reinforced concrete beams for shear is a complex problem, and its formulas are obtained by experimental or semi-empirical methods on the basis of various theoretical calculation models. In Russian standards, the calculations of reinforced concrete structures under the action of shear forces are performed based on the length of the most dangerous projection of the inclined section on the longitudinal axis of the element, and the formulas lack parameters that would take into account the influence of longitudinal reinforcement on the strength of inclined sections. The novelty of the present research is that the author, based on the theory of Prof. A.S. Zalesov, proposed a new approach to determine the shear strength of inclined sections of elements reinforced without stirrups. In the new approach, an analytical expression is obtained that takes into account the work of longitudinal regular reinforcement by introducing a longitudinal reinforcement coefficient. Examples of calculations performed according to the proposed methodology and SP 63.13330.2018 are given, where a series of experimentally tested specimens are taken for comparative calculation. The results of comparative calculations have shown the adequacy of the new approach to determine the strength of inclined sections of reinforced concrete elements reinforced without stirrups.
Keywords: reinforced concrete beam, beams without stirrups, inclined crack, shear stress, normal stress, strength, shear force
3D – printing is the quickly expending area of modern industry. In this review is carrying review of novel US patents on this topics.
Keywords: 3D - printing; application in civil & military engineering; application in industry and medicine
Bar structures are widespread in construction due to their economy, freedom of design shapes and sizes. As a result, automation of design and calculation of such structures is an urgent task. As part of the study, the task of developing a software module that generates a map of optimal cutting of rolled metal based on the results of calculations of rod structures has been implemented. The algorithm under consideration takes into account such features of the cutting optimization problem as taking into account the width of the blade, the possibility of using half the size of the rolled product, support for optimization of several sections, and welding of parts in case the length of the workpiece is exceeded. The software module is developed using JavaScript and C# languages. The ability to automatically generate cutting maps based on the results of optimization of rod structures increases the efficiency of designing building structures.
Keywords: Design in construction, bar structure, computing system, web development, design in construction, rod structure, computer system, web development, optimal cutting, rolled metal, cutting map
The article is devoted to the use of reinforced soils in the base of pavements of highways located in the I road-climatic zone. The features of the operating modes of reinforced foundation soils are considered, and their physical and mechanical characteristics with various combinations of mineral and polymer modifiers are determined. The authors analyze the advantages and disadvantages of using reinforced soils. The article also discusses the design and construction of roads using reinforced soils.
Keywords: highway, road pavement, foundation, soils, reinforced soils, modifiers
Nowadays, numerical methods are widely used to realise complex calculations.Verification of the correctness of the numerical calculation results is a relevant task. The validity of the results can be confirmed by determining the stress-strain state by various methods. This paper presents the results of the calculation of thin isotropic ring spherical shells of constant thickness with half-shell angle in the range of (90-170) degrees by two numerical methods. The results of solving the system of differential equations of the general moment theory of shells with the use of the computer mathematics system (Maple 2017) and the finite element method (FEM) are discussed. The given examples show that the calculation results with the use of the selected finite element KE-44 coincide with an accuracy of 10-15 % for shells with a half-shell angle of 120 degrees. When the angle is increased to 170 degrees, the difference in function values becomes significant. The paper gives some examples of calculation of ring spherical shells under the action of one and three annular loads. The variation of axial and radial displacements, of meridional bending moment for shells with the ratio of radius of the curvature to shell thickness 25, 50, 100, 200 is shown. Plots of meridional bending moment and moment isopole are given.
Keywords: elastic, spherical shell, numerical method, computer mathematics system, finite element method.
In accordance with the requirements of Federal Law No. 384-FZ, the safety and reliability of buildings and structures must be ensured. One of the ways to confirm the safety and reliability of building structures is to conduct field tests. The authors of this article have developed a method for full-scale testing of a reinforced concrete beam with a span of 14.52 m as part of a monolithic reinforced concrete ribbed floor. The procedure for testing the beam was drawn up with the development of measures to ensure safety during work, the adjustment of the beam testing method by loading was performed, the beam was tested by loading method with fixation of its deflections, followed by analysis of the test results. The test results showed that the developed method can be used as a full-scale test to confirm the safety and reliability of building structures, namely horizontal reinforced concrete structures.
Keywords: building structures, beam, destruction, safety, methodology, technical condition, field tests
Reinforced concrete structures must have sufficient reliability throughout their entire service life. In problems related to predicting service life based on an assessment of the technical condition, reliability can be considered as the probability of failure-free operation of structures, which consists in the ability to perform the required functions under given conditions during the design life. One of the methods for solving this kind of problem is statistical methods. The beam reliability calculation was carried out. It was further assumed that the beam was subject to degradation. As a result, a graph was constructed of the dependence of reliability on the depth of corrosion penetration into the compressed concrete zone. This graph also shows how the category of the technical condition of the beam changes over time.
Keywords: reinforced concrete structure, bendable structure, prediction, service life, reliability, technical condition, degradation impact
Numerical methods for calculating shells provide a wide range of solutions when varying various parameters. The object of this study is a mathematical model of thin isotropic elastic shells of revolution of constant thickness. The problem is solved from the position of moment theory.To determine the stress-strain-state of the shell, the solving system is obtained by transforming the basic systems of equations of rotational shells by moment theory and the variables separation. All SSS and load components are decomposed into Fourier series along the circumferentail coordinate. A programme in the Python programming language was written to verify the numerical solution by a computer mathematics system (CMS-Maple 17). Matplotlib library was used for plotting graphs. Examples of numerical calculation of ring spherical shells for the action of ring loads are given. The variants of action of one and two ring loads on shells with different conditions of support along the contours and different half shell angles are presented. The difference between the calculation results of the two methods for bending moment functions and displacement functions is tabulated. The highest value of the difference is 0.0015%. Plots of the variation of meridional bending moment under the action of two ring loads are presented. The variants of rigid pinching along the contours and hinged support are considered. Exsmples are given for shells with the ratio of radius of curvature to shell thickness equal o R/h = 25, 50, 150, 200. Considered of the half shell angles equal to 90, 100, 130 degrees.
Keywords: rotation shell, spherical, isotropic, elastic, computer mathematics system, Python programming language
This article considers a new type of structures in the form of lightweight stainless steel floor slabs, gives an overview of application in construction practice, discusses the advantages and disadvantages. Based on the results of a series of structural analysis of several conditional models of buildings with different structural systems, the parameters of economic efficiency in the form of reduction of total metal intensity are determined. The area with increased efficiency of application of the considered plates in buildings is defined and the vector of necessary further research on the topic is outlined.
Keywords: B-Core slabs, multilayer floor slabs, stainless steel, metal cost reduction, efficient application area, structural building layouts
The article addresses the issue of determining the ultimate eccentric compressive longitudinal force from an external load acting on a compressed reinforced concrete element. The calculation assumptions are adopted in accordance with the current code of practice SP 63.13330.2018. The transformation of the initial formulas given in this code allowed the explicit solution of the cubic equation with respect to the compressive longitudinal force without the need for iterative calculation methods. The solution thus obtained can be employed in the design process to determine the optimal section dimensions.
Keywords: reinforced concrete, excentric compression,ultimate forces
The article discusses the use of organic binders to modify the properties of cement soils. The scope of application of cement soils in construction practice, including the construction of highways, is considered. The influence of the use of organic binders as a complex additive that modifies the strength characteristics of cement soils has been studied. The influence of the use of complex modifiers and additives on the frost resistance and water permeability of cement soils has been determined.
Keywords: cement soil, organic binder, highway, working layer, frost resistance, modifiers
The article deals with the peculiarities of the results of tests carried out to determine the characteristics of the contact zone organized by stamping on a steel plate. During the test, the specimen was in the steel mold in which it was manufactured. The steel form was used to prohibit horizontal movement of the steel thin plates and minimize the effect of uneven slippage of the steel gouge in the direction perpendicular to the shear force. The considered tests were carried out according to a specially developed methodology, which took into account the specifics of the contact zone shear operation, the applied tooling and took into account the set objectives of the study.
Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite design
The paper deals with the problem of choosing the most rational form of spatial metallic cross-barrel coating. Mathematical models of flat structural coating, elliptical paraboloid and hyperbolic paraboloid coatings in SCAD software package based on finite element method are analyzed. Nodal connections of rod elements of coatings are taken according to the system “Kislovodsk”. The obtained parameters of stress-strain state of three different structural coverings allow us to speak about practically identical operation of the structures.
Keywords: structural covering, spatial covering, cross-bar covering, stress-strain state, “Kislovodsk” system, SCAD program complex, finite element method, hyperbolic paraboloid, elliptic paraboloid
Layered reinforced concrete beams made of multi-modulus of elasticity concretes are increasingly used in engineering practice. The step-by-step iterative method in combination with numerical integration in the calculation of such structures using a nonlinear deformation model and real deformation diagrams is a rational solution, despite the currently lack of a generally recognized approach to assessing the stress-strain state of sections of layered beams.
Keywords: double-layer reinforced concrete beams, normal cross-sections, nonlinear deformation model, high-modulus concrete, neutral axis coordinate
When studying the problems of water filtration to a single horizontal imperfect drain of finite length, in a system of interacting horizontal imperfect drains, it is necessary to consider spatial (three-dimensional) filtration problems. Unlike flat (two-dimensional) problems, spatial filtering has been studied in less detail, since it is difficult to obtain rigorous solutions to their problems.
Keywords: water supply facilities, filtration, equipotentials, drainage, borehole, pressure reservoir, drain, pressure, inflow, reservoir, watercourse
This article discusses several ways to determine the calculated lengths of steel columns in the plane of the frame. By analyzing existing techniques, the most successful method of selecting the calculated lengths for steel columns in a free multi-storey frame was determined. Taking into account the non-standard case of fastening crossbars to the considered section in the frame of the overpass, using the LIRA CAD PC, as well as the Crystal module (implemented in SCAD), the loss of stability of equally loaded elements in the most sensitive area is clearly shown.
Keywords: Euler's formula, loss of stability, coefficient of calculated length, calculated length, coefficient of stability margin, finite elements
The article discusses the issues of stability of pedestrian paths and staircases located on sloped areas and interacting with a complex geological environment. The features of designing construction projects on sloping areas are considered. The reasons for the occurrence of various defects and destruction on the staircase, located on the embankment of Khabarovsk, were investigated. An assessment of the stability of the structure during repair work is given. Measures are proposed to increase the stability of the structure.
Keywords: staircase, slope, slope stability, stress-strain state, fortifications