Browsing by Author "Ковальчук, Станіслав Богданович"
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ItemAn analytical solution to the problem of thermoelastic bending of a multilayer beam with different temperature of longitudinal faces(2021-06) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemAnalytical Determination of Reactive Forces for Curvilinear Bars with a Flat Axis of Arbitrary Shape / Аналітичне визначення реактивних зусиль для криволінійних брусів із плоскою віссю довільної форми(2019-12) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemAnalytical Modeling of Concentrated and Localized Loads of Bars With a Curvilinear Flat Axis. Part 2. Modeling Localized Loads and Application Examples / Аналітичне моделювання зосереджених та локалізованих навантажень брусів із криволінійною плоскою віссю. Частина 2. Моделювання локалізованих навантажень та приклади застосування(2019-09) Ковальчук, Станіслав Богданович ItemAnalytical Solution of the Problem of Thermoelastic Deformation of a Nonuniformly Rotating Multilayer Disk(2020-03) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович; Зiньковський, Анатолiй Павлович ItemAnalytical Solution to the Plane Bending Task of the Multilayer Beam with a Circular Axis under Normal Uniform Loading(2020-09) Ковальчук, Станіслав Богданович ItemBasic Stress-Strain State of a Multilayer Circular Ring under the Action of Mutually Opposite Normal Forces / Основное напряженно-деформированное состояние многослойного кругового кольца под действием взаимно противоположных нормальных сил(2019-03) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemBasic Stress-Strain State of a Multilayer Symmetric Circular Arch under the Action of Normal Forces in the Middle Section. Report 1. Arches of High Curvature / Аналітичний розв’язок задачі згину багатошарової симетричної кругової арки під дією нормальної сили у середньому перерізі. Повідомлення 1. Арки великої кривизни(2019-06) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemDETERMINATION OF ELASTOPLASTIC COEFFICIENT OF SHOCK INTERACTION OF SPHERICAL INDENTER WITH DEFORMABLE HALFSPACE(Eastern-European Journal of Enterprise Technologies, 2013-01) Горик, Олексій Володимирович; Ковальчук, Станіслав Богданович; Шулянський, Г. А.Erosive wear due to contact of metal surfaces with flying solid particles is a typical problem of machinery. The intensity of wear depends on the hardness of the material of wearing surface and the kinetic energy of moving solid particles. A measure of wear is associated with the parameters of the track left by a particle on the surface of parts. Thus the problem of linking of these components of the process of shock interaction of counter-bodies arises.On the basis of the elastoplastic model of shock interaction of a solid particle with a flat metal surface we have created a method of determining the coefficient, which characterized the elastoplastic properties of deformable half-space at dynamic imbedding of a spherical indenter in it. This allowed predicting the intensity of erosive wear. The coefficient was determined on the basis of existing or special laboratory results of studies of shock embedding of the indenter into prototypes, and on the basis of laboratory analytical calculations. This allowed us to summarize the available experimental data on the current input parameters of the considered process. The elastoplastic coefficient depends on the initial velocity and the diameter (mass) of attacking body and on the hardness of the material of the attacked half-space. ItemElasticity Theory Solution of the Problem on Bending of a Narrow Multilayer Cantilever with a Circular Axis by Loads at its End(2018-11) Ковальчук, Станіслав Богданович ItemElasticity Theory Solution of the Problem on Plane Bending of a Narrow Layered Cantilever Beam by Loads at Its Free End(2018-05) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemExact Solution of the Problem of Elastic Bending of a Multilayer Beam under the Action of a Normal Uniform Load(2019-08) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemExact Solution of the Problem on Elastic Bending of the Segment of a Narrow Multilayer Beam by an Arbitrary Normal Load(2020-03) Ковальчук, Станіслав Богданович ItemMaintenance of a loaded capability of reinforced concrete console girders of the VIP-grandstand at the stadium “Vorskla” in Poltava city(Державний науково-дослідний інститут будівельних конструкцій, 2018-02) Горик, Олексій Володимирович; Ковальчук, Станіслав БогдановичThe work is devoted to topical issues of a maintenance and renewal of a normal technical condition of constructional parts of the grandstand structure of the stadium “Vorskla” in Poltava city. The object of the research is reinforced concrete console girders of carcass frames of the stadium guest grandstand. Because of failed designing decisions connected with the reconstruction, these elements are practically at the end of their estimated reserve of loaded capability and require its improvement through arrangement of the construction strengthening. The optimal strengthening system in which the removal of the girder console part is limited by an additional elastic support with a preliminary compression force has been suggested. The transmission of the load estimated part to the elastic support of the strengthening system allowed to redistribute internal forces decreasing the estimated moment of flection on the supporting structure and in the bay avoiding a change of its sign. It is identified that in the process of the elastic element installment the intensity of the formed preliminary compression force will decrease by means of a girder secondary deflection. The estimates of its deflections taking into account a concentrated force formed by a working element of the strengthening system has been made for consideration of additional related deformation of the strengthening system and the girder. When identifying deflections, the reinforced concrete girder was considered as a composite discrete-heterogeneous bar made of homogeneous concrete matrix reinforced by very strong steel phases. It gave the possibility to take constitutive relation of the iteration movable model of the fold of composite discrete-heterogeneous bars as a basis of the reinforced girder deformation analysis under the conditions of limited deformation. General solutions of defining equations are received independently for each section of different stiffness. Received solutions at the stage of consideration of boundary conditions were adjusted by means of balancing of linkage and static deformation parameters at the edge of analyzing sections. Received amounts of deflections allowed to identify necessary constructive sizes of the strengthening system, with which the given level of the preliminary compression force in the working element is promoted in the designing position of the working element. ItemMajor stress-strain state of double support multilayer beams under concentrated load. Part 1. Model construction(Інститут проблем машинобудування ім. А.М. Підгорного, 2018-02) Ковальчук, Станіслав Богданович; Горик, Олексій ВолодимировичThe development of composite technologies contributes to their being widely introduced into the practice of designing modern different-purpose structures. Reliable prediction of the stress-strain state of composite elements is one of the conditions for creating reliable structures with optimal parameters. Analytical theories for determining the stressstrain state of multilayer rods (bars, beams) are significantly inferior in development to those for composite plates and shells, although their core structural elements are most common. The purpose of this paper is to design an analytical model for bending double support multilayer beams under concentrated load based on the previously obtained solution of the elasticity theory for a multi-layer cantilever. The first part of the article includes a statement of the problem, accepted prerequisites and main stages of constructing a model for bending a double-support multi-layer beam with a concentrated load (normal, tangential force and moment) and general-view supports in the extreme cross-sections. When building the model, the double support beam was divided across the loaded cross-section and presented in the form of two separate sections with equivalent loads on the ends. Using the general solution of the elasticity theory for a multilayer cantilever with a load on the ends, the main stress-strain state of the design sections was described without taking into account the local effects of changing the stress state near the concentrated load application points and supports. The obtained relations contain 12 unknown initial parameters. To determine them on the basis of the conditions of joint deformation (static and kinematic) of design sectors, a system of algebraic equations has been constructed. The constructed model allows one to determine the components of the main stress-strain state of double support beams each consisting of an arbitrary number of orthotropic layers, taking into account the amenability of their materials to lateral shear deformations and compression. ItemMajor Stress-Strain State of Double Support Multilayer Beams Under Concentrated Load. Part 2. Model Implementation and Calculation Results(Інститут проблем машинобудування ім. А.М. Підгорного, 2019-04) Ковальчук, Станіслав Богданович; Горик, Олексій ВолодимировичThe development of composite technologies contributes to their wide introduction into the practice of designing modern different-purpose structures. Reliable prediction of the stress-strain state of composite elements is one of the conditions for creating reliable structures with optimal parameters. Analytical theories for determining the stress-strain state of multilayer rods (bars, beams) are significantly inferior in development to those for composite plates and shells, although their core structural elements are most common. The purpose of this paper is to design an analytical model for bending double support multilayer beams under a concentrated load, with the model based on the previously obtained elasticity theory solution for a multilayer cantilever. The second part of the article contains examples of the implementation of the model for bending double-support multilayer beams under a concentrated load, with the model constructed in the first part of the article. Using this model, solutions to the problems of bending multilayer beams with different types of fixation of their extreme cross-sections were obtained. The resultant relations were approbated using test problems for determining the deflections of homogeneous composite double-support beams with different combinations of fixation, as well as in determining the stresses and displacements of a four-layer beam with a combination of a rigid and hinged fixation at its ends. The results obtained have a slight discrepancy with the simulation results by the finite element method (FEM) and the calculation by the iterative model for bending composite bars, even for relatively short beams. In addition, it is shown that the neglect of the shear amenability of layer materials results in large errors in determining the deflections, and in the case of statically indefinable beams, reactive forces and stresses. The approach used in the construction of the model can be extended to the case of beams with arbitrary numbers of concentrated forces and intermediate supports, and to calculate multilayer beams with different rigidity of their design sections. ItemSolution of a Transverse Plane Bending Problem of a Laminated Cantilever Beam Under the Action of a Normal Uniform Load(2018-05) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemSolution to the Task of Elastic Axial Compression–Tension of the Composite Multilayered Cylindrical Beam(2019-03) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович; Павліков, Андрій Миколайович; Антонець, Анатолій Вікторович ItemSolving the Problem of Elastic Bending of a Layered Cantilever Under a Normal Load Linearly Distributed over Longitudinal Faces(2020-01) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович ItemThe problem of plane bending a direct composite beam of arbitrary cross-section and the prerequisites for its approximate analytical solution(2021-06) Ковальчук, Станіслав Богданович; Горик, Олексій Володимирович; Антонець, Анатолiй Вікторович