Кафедра "Теоретична механіка та опір матеріалів"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/1121

Офіційний сайт кафедри http://web.kpi.kharkov.ua/teormeh

Кафедра "Теоретична механіка та опір матеріалів" була утворена у грудні 2021 року шляхом об’єднання кафедр "Теоретична механіка" та "Механіка суцільних середовищ та опір матеріалів" (НАКАЗ № 552 ОД від 26.11.2021 року).

Кафедра "Теоретична механіка" була створена ще у 1925 році в Харківському технологічному інституті, а її першим завідувачем став професор Іван Бабаков, відомий вчений у галузі теорії коливань. Теоретичну механіку в Харківському практичному технологічному інституті (нині Національний технічний університет "Харківський політехнічний інститут") викладали ще з 1887 року всесвітньо відомі вчені академік Ляпунов Олександр Михайлович (1887-1893) і академік Стеклов Володимир Андрійович (1893-1903). Кафедра «Опір матеріалів» – первісна назва кафедри "Механіка суцільних середовищ та опір матеріалів", пройшла еволюцію досліджень від експериментальної та будівельної до обчислювальної та комп’ютерної механіки.

Новостворена кафедра входить до складу Навчально-наукового інституту комп'ютерного моделювання, прикладної фізики та математики Національного технічного університету "Харківський політехнічний інститут".

У складі науково-педагогічного колективу кафедри працюють: 2 доктора технічних наук, 8 кандидатів технічних наук; 1 співробітник має звання професора, 8 – доцента.

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Analysis of Various Approaches to Modeling of Dynamics of Lifting-Transport Vehicles
(Science Publishing Corporation, 2018) Grigorov, O. V.; Druzhynin, E. I.; Anishchenko, G. O.; Strizhak, M. G.; Strizhak, V. V.
The results of analytical and numerical modeling of dynamic characteristics of linear and non-linear mathematical models of the "trolleyload" system of bridge and container cranes are presented. KiDyM software complex is used for numerical modeling, which, based on the use of the apparatus of structural matrices and the built-in computer algebra system, allows the construction of ordinary differential equations of motion of the class of systems under consideration at the analytical level. Recommendations on the possible use of the considered mathematical models of the "trolley-load" system in various regular and forced operation modes of bridge and container cranes are given on the basis of the analysis. The ratio of the results of calculations for various design models of regular and forced operation of the bridge crane has been established. The magnitude of the distribution of the maximum values of the dynamic characteristics of motion of the container crane has been designed by calculating the forced operation mode using various mathematical models.
Anisotropic creep and damage in structural elements under cyclic loading
(Kluwer Academic/Plenum Publishers, 2015) Breslavskii, D. V.; Metelev, V. A.; Morachkovskii, O. K.
A method is described to calculate creep and damage in structural elements under cyclic loading. Materials exhibiting anisotropic creep-damage behavior are considered. The results of calculating the deformation and fracture of structural elements at a plane stress state are presented.
Asymptotic methods and finite element method in cyclic creep-damage problems
(Львівський національний університет ім. І. Франка, 2015) Breslavsky, D. V.; Mietielov, V. O.; Morachkovsky, O. K.; Pashchenko, S. O.; Tatarinova, О. А.
Augmented reality in logistics
(Національний технічний університет "Харківський політехнічний інститут", 2019) Grigorov, O. V.; Anischenko, G. O.; Petrenko, N.; Alieksieiev, V.
Big data in logistics
(Національний технічний університет "Харківський політехнічний інститут", 2019) Grigorov, O. V.; Anischenko, G. O.; Petrenko, N.; Parkhomenko, O.
Biomechanical study athletes’ movement techniques in the hurdles (on example of phase of flight)
(Kharkiv State Academy of Design and Arts, 2014) Adashevskiy, V. M.; Iermakov, S. S.; Korzh, N. V.; Muszkieta, Radosław; Krzysztof, Prusik; Cieślicka, Mirosława
Purpose: To design a theoretical biomechanical model of athletes’ movement techniques in the hurdles and then check there movements on real athletes. Material: In the practical part of the study participated 10 smortsmen. Results: Showing the possibility of constructing a theoretical model of hurdling technique. The basis of cons tructing a model using the known approaches in theoretical mechanics. Shows the calculated and actual performance movement of the athlete. Conclusions: The developed model provides a good theoretical understanding of the interactions of individual elements of movement and the ability to simulate different situations and to determine the optimal values of the kinematic and dynamic characteristics of the movement of the athlete. The model allows the individual elements of motion correction directly in the process of training. When analyzing art movement should consider specific features of physical development and anthropometric characteristics of the athlete's body.
Biomechanics aspects of technique of high jump
(Kharkiv State Academy of Design and Arts, 2013) Adashevskiy, V. M.; Iermakov, S. S.; Marchenko, A. A.
The purpose of work consists in the theoretical ground of optimum biomechanics descriptions in high jumps. A mathematical model is developed for determination of influence on the height of jump: speed and corner of flight of centre-of-mass during pushing away, positions of centre-of-mass body of sportsman in the phases of pushing away and transition through a slat, forces of resistance of air environment, influences of moment of inertia of body. The basic technical run-time errors of sportsman are selected exercises. To biomechanics descriptions, to the step-up effectiveness of high jumps belong: speed of flight of centre-of-mass sportsman (4.2-5.8 meters in a second), corner of flight of centre-of-mass body (50-58 degrees), height of flight of centre-of mass body (0.85-1.15 meter). Directions of choice of necessary biomechanics descriptions which a sportsman can realize are shown. Offered recommendation on the increase of effectiveness of high jumps.
Comparing hydraulic and electromechanical drives by electric motor's power
(2019) Grigorov, O. V.; Anishchenko, G. O.; Druzhynin, E. I.; Strizhak, V. V.; Strizhak, M. G.; Mаlashchenkо, V. O.
The authors have made the analysis of energy consumption by positive-displacement hydraulic drive and asynchronous motor with phase rotor in the course of crane mechanisms operation at all stages of motion: acceleration, movement at nominal or intermediate speed, and deceleration. There have been determined and compared equivalent capacities per work cycle for electric and hydraulic drives of crane mechanisms depending on operating conditions group and operation time. There has been justified the decrease of rated capacity of electric motor of crane mechanisms’ hydraulic drive as compared with the case of applying asynchronous motor with phased rotor for the same mechanisms.
Computational analysis method of the electromagnetic field propagation and deformation of conductive bodies
(Національний технічний університет "Харківський політехнічний інститут", 2023) Lavinsky, D. V.; Zaitsev, Yu. I.
The electromagnetic field is an integral attribute of the operation of many technical and technological systems. The action of an electromagnetic field leads to deformation, a change in temperature, a change in the physical properties of the materials. Problem. High-intensity electromagnetic fields can cause such a strong deformation of conductive bodies that it can lead to irreversible shape change or destruction. This fact is used in a class of technological operations: electromagnetic forming. Here, both the workpiece and the equipment are subjected to intense force action. As a result, equipment elements may become inoperable. Goal. Creation of a computational analysis method of the electromagnetic field propagation in systems of conductive bodies and subsequent analysis of deformation. Application of this method to the study of processes in electromagnetic forming systems in order to determine rational operational parameters that provide the result of a technological operation. Methodology. A variational formulation of the problems of an electromagnetic field propagation and deformation of conductive bodies systems is used. Numerical modeling and analysis are performed using the finite element method. Results. In a general form, a system of resolving equations for the values of the vector magnetic potential and displacements is obtained. The influence of the electromagnetic field is taken into account by introducing electromagnetic forces. The results of calculations for a technological system designed for electromagnetic forming of curved thinwalled workpieces are presented. Originality. For the first time, a method of computational analysis is presented, which involves modeling within the framework of one design scheme both the process of electromagnetic field propagation and the process of deformation. Practical significance. The proposed method of computational analysis can be used for various technological systems of electromagnetic forming in order to determine the rational parameters that ensure both the operability of the equipment and the purpose of the technological operation - the necessary shaping of the workpiece.
Computer and computational analisys of the biomechanics of swimming
(Громадська наукова організація "Всеукраїнська асамблея докторів наук з державного управління", 2023) Lavinsky, D. V.; Adashevsky, V. M.; Druzhynin, Ye. I.
The article deals with the issues of computer and computational modeling and analysis of the biomechanics of one of the most technically complex sports - swimming. Computer and computational modeling is currently an impotent part of various scientific researches. Such modeling in many cases allows either to replace full-scale experiments or to determine their rational parameters, thereby accelerating research. Computational modeling and simulation is widely used in the study of movement in various sports, which belongs to a wide class of biomechanical problems. Here, the use of computer calculations makes it possible to determine the rational parameters of an athlete's sports actions, which lead to higher sports results. It should be noted that the accuracy and reliability of computational modeling in the biomechanics of sports depend on the degree of approximation of computational schemes and models to reality. The creation of design schemes and models is impossible without the use of the results of field measurements. Based on the analysis of existing sources of information, an approach was formulated to create design schemes for studying the movement of an athleteswimmer along the distance. The systems of differential equations of motion for different stages of the distance are presented. For computer modeling, the KiDyM software package is applied, which uses the relations of the computer algebra system to construct differential equations of complex mechanical systems motion. The analysis of the presented and similar graphical information allows determining the rational values of certain parameters of the athlete-swimmer's sports actions, which allow achieving high sports results. This information allows us to adjust the technique of a particular athlete, taking into account the characteristics of his anatomy and physiology. Similar computational studies based on computer simulations can be performed for other technically complex sports.
Creep and damage in shells of revolution under cyclic loading and heating
(Elsevier Ltd., 2014) Breslavsky, D.; Morachkovsky, O.; Tatarinova, O.
Creep of cyclically loaded thin shells of revolution and their fracture due to creep and fatigue mechanisms are studied. Creep-damage equations for steels and nickel-based alloys are built by the use of scalar damage parameter. Constitutive equations were derived using the method of asymptotic expansions and averaging over a period of cyclic loading. The cases of fast and slow varying of temperature and loading are regarded. General problem statement and method for solution of creep problems at cyclic loading are presented. Strain–stress state in shell structures is determined by the use of homemade FEM creep–damage code, where the finite element of conical shell is used. Results of creep–damage problem for conical panel are discussed.
Creep damage processes in cyclically loaded structural members
(Serbian Chamber of Engineers, 2012) Breslavsky, D.; Morachkovsky, O.
The paper contains the description of the cyclic creep damage law that allows to estimate the long-term strength of metallic materials in wide range of frequencies of loading and heating. Asymptotic methods and procedures of averaging in a period were used for deriving the damage laws.
Cyclic creep damage in thin-walled structures
(Mechanical Engineering Publications, Ltd., 2000) Altenbach, H.; Breslavsky, D.; Morachkovsky, O.; Naumenko, K.
Thin-walled structural elements are often subjected to cyclic loadings. This paper presents a material model describing creep behaviour under high-cycle loading conditions (N greater than or equal to 5 x 10(4)-10(5)). Assuming that the load can be split into two joint acting parts (a static and a superposed, rapidly varying small cyclic component), the asymptotic expansion of two time-scales has been applied to the governing equations of the initial-boundary value creep problem. The system of equations determine two problems. The first is similar to the creep problem by quasi-static loading. The second is the problem of forced vibrations. Both the problems are coupled by constitutive equations. The model is applied to the simulation of the cyclic creep damage behaviour of thin-walled structural elements. The results are discussed for two special numerical examples (a conical shell and a circular plate). The simulations show that the creep and the damage rates as well as the failure time are strongly sensitive to the redistribution of the stress state cycle asymmetry parameter A(s). The values of A(s) increase during the creep process. For particular cases of the loading frequency, A(s) can exceed the critical value. In this case the material model must be extended in order to consider the creep-fatigue damage interaction.
Cyclic thermal creep model for the bodies of revolution
(Springer New York, 2011) Breslavskyi, D. V.; Korytko, Yu. M.; Morachkovskyi, O. K.
The new method of solving thermal creep problems, accounting for cyclic variations of external force and thermal fields was put forward. Asymptotic expansions and period averagings were used to derive the systems of basic and auxiliary equations. The equation of state for cyclic thermal creep was proposed and validated. Numerical simulation of the creep of cylinders under cyclic temperature variations was carried out.
Edge fixing effect on the life of a vacuum chamber thin spherical cover subjected to creep damage
(Kluwer Academic/Plenum Publishers, 2011) Morachkovskii, O. K.; Romashov, Yu. V.
Within framework of the numerical studies of creep resource of a thin spherical cover of a vacuum chamber, we present mathematical formulation and the calculation method for the solution of the initial boundary value problems of the creep theory of thin shells with account of the damage accumulation process of the material. The effect of edge fixing along the normal and tangential lines to the median surface, as well as angular edge fixings, on the cover life in creep are studied under atmospheric pressure creep conditions. The calculation data obtained made it possible to determine the dependence between the cover life in creep and its edge fixing conditions: this effect is strong by the latent fracture time and weak by the allowable deflection values
Elastoplastic deformation of bodies interacting through contact under the action of pulsed electromagnetic field
(Springer New York, 2016) Lavinsky, D. V.; Morachkovskii, O. K.
A formulation is presented for the problem of elastoplastic deformation of the system of electrically conductive bodies under the action of pulsed electromagnetic field. The numerical technique for solving the problem is based on the finite element method. Deformation of bodies interacting through contact during the pulsed magnetic treatment of materials is analyzed. The influence of the manufacturing and design parameters of the inductor–workpiece system on its stress-strain state is investigated.
FE-analysis of dynamic creep-damage in thin-walled structures
(Springer-Verlag, 2002) Morachkovsky, Oleg; Breslavsky, Dmitry; Burlayenko, V. N.
The models for description of creep-damage behaviour in materials and thin shallow shells and plates deforming in conditions of joint action of static and fast cyclic load are given. The properties of the proposed material model were established by comparison of experimental and numerical data. The method for numerical simulation by in-house code of a dynamic creep and long-term strength of shallow shells and plates is created on the basis of the FEM. New laws of dynamic creep influence on stress-strain state, shaping and fracture of thin-walled elements of structures had been established by numerical calculations. With the purpose of verification of the created method of dynamic creep numerical simulation of rectangular plates made of an aluminium alloy were carried in order to verify the method of calculation.
Features of deforming of composite inductors during electromagnetic processing of materials
(Одеський національний морський університет, 2023) Lavinsky, D. V.; Anischenko, G. O.; Konokhov, V. I.
The article proposes an effective method of analyzing the elastic-plastic deformation of composite structures under the influence of an electromagnetic field. The general mathematical formulation of the coupled problem of the deformation of conductive bodies in the presence of an electromagnetic field is considered. To construct a numerical solution method, the initial problem is reduced to finding the minimum of the total energy of the system. The finite element method is used as a numerical solution method. The proposed method is applied to the analysis of the deformation of the "inductor-workpiece" system of the technological operation of magnetic pulse processing of metals. Conclusions. Some results are presented that allow making certain recommendations regarding the design and application of technological operations of a similar class.
High temperature creep and damage accumulation in cyclically loaded axisymmetrical bodies of revolution
(National Technical University "Kharkov Polytechnic Institute", 2010) Breslavsky, D.; Korytko, Yu.; Morachkovsky, O.
The paper presents the constitutive equations as well as the data of numerical simulation of creep-damage problems of cyclically loaded and heated axisymmetrical structural members. The procedure of constitutive equations deriving is discussed. The experimental and numerical data have been obtained for cyclically heated specimens made from high quality steel were compared in order to verify the flow rule and damage parameter equation. The problem of creep and damage accumulation in the nipples of the regenerator for catalytic cracking of petroleum was analyzed with consideration of different temperature cycle parameters.
Identification of effective properties of particle reinforced composite materials
(Springer-Verlag, 1998) Kushnevsky, V.; Morachkovsky, O.; Altenbach, H.
For the determination of effective elastic properties an energy averaging procedure has been used for particle reinforced composite materials. This procedure is based on finite element calculations of the deformation energy of a characteristic volume element. The proposed approach allows the determination of effective properties of particle reinforced composite with acceptable precision. The calculated effective properties of the composite are found in range between upper and lower Hashin-Shtrikman bounds. The averaging elastic properties of the composite depend on the properties of the particles, matrix volume fraction of the particles and some parameters taking into account the influence of the interphase between matrix and particles. These dependencies can be presented by simple analytical functions approximatically. An identification procedure basing on numerical experiments allows the estimation of the unknown approximation parameters. The obtained functions describe precisely the numerical data for any relationship between material constituents.