Technical Mechanics
type: channel
description: Scientific journal TECHNICAL MECHANICS ISSN 1561-9184 (Print), ISSN 2616-6380 (Online) Technical Mechanics is dedicated to advancing scientific knowledge and fostering innovation in the fields of aviation and space engineering, applied mechanics, and material science. Its primary aim is to provide a platform for the dissemination of original research articles, comprehensive reviews, and theoretical developments that contribute to the progress of engineering sciences and their practical applications. In 1993, the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine started to publish an interdepartmental collection of scientific papers entitled Tekhnichna Mekhanika (the Ukrainian for technical mechanics), which in September 1997 received the status of a scientific journal. In 2017, the institute received a new state registration certificate, according to which the journal has the official English title of Technical Mechanics and has the right to publish papers in English and to be distributed internationally. The journal publishes papers in Ukrainian and English (at authors’ choice). The journal is indexed in Google Scholar та Index Copernicus. The journal is sent to the V. I. Vernadsky National Library of Ukraine to be placed in the Scientific Periodicals of Ukraine database. All papers are assigned a DOI (CrossRef). DOI prefix: 10.15407/itm Abbreviated title: Teh. Meh.; ТМ. Authors retain copyright to their materials published in Technical Mechanics, and the journal does not claim any intellectual property rights to the authors’ content. Authors may deposit the final version of their paper in institutional or any other repositories where the paper will be in open access (at their own choice). Technical Mechanics is in diamond open access, i.e., free both for authors to publish in and for readers to access all papers and issues. Once published, all papers are immediately in open access for reading, dow…
publisher: текст 3
language: en-US
publication name: Technical Mechanics
items: SPACEBORNE THERMAL IMAGING OF THE EARTH SURFACE: THE TRENDS AND THE DEVELOPMENT PROSPECTS
items: ACCOUNTING FOR THE EFFECT OF PULP PARAMETERS WHEN SIMULATING THE FINE SCREENING PROCESS
items: ON THE RESEARCH RESULTS OF THE SCIENTIFIC SCHOOL AT THE NATIONAL ACADEMY OF SCIENCES OF UKRAINE "DYNAMICS OF SPACE TECHNOLOGY OBJECTS" IN 2021–2025
items: FEATURES OF THE MATHEMATICAL SIMULATION OF DYNAMIC PROCESSES IN THE RECONFIGURABLE PROPELLANT FEED HYDRAULIC SYSTEM OF LIQUID-PROPELLANT ROCKET ENGINES
items: EXPERIMENTAL METHODS OF SOLID ROCKET PROPELLANT CHARACTERIZATION
items: FINITE-ELEMENT ANALYSIS OF THE STRESS AND STRAIN FILED OF THIN FUNCTIONALLY GRADED PLATES WITH A CIRCULAR HOLE UNDER VARIOUS TYPES OF LOADING
items: MODAL ANALYSIS OF A HORIZONTAL SHELL STRUCTURE UNDER BLAST LOADING
items: ANALYSIS OF THE ANTIPLANE DEFORMATION OF A CRACKED QUASICRYSTAL WITH CONSIDERATION FOR SURFACE EFFECTS
items: FINITE-ELEMENT SIMULATION OF THE IN-SERVICE STRESS AND STRAIN FIELD OF HIP JOINT ELEMENTS BASED ON COMPUTER TOMOGRAPHY DATA
items: DARRIEUS ROTOR SPEED CONTROL BY SIMULTANEOUS CHANGES IN THE ROTOR CONFIGURATION AND THE GENERATOR BRAKING TORQUE
items: STUDY OF THE PERFORMANCE OF PLANAR ANTENNA ARRAYS AS A FUNCTION OF THEIR TOPOLOGY AND THE PROPERTIES OF THEIR STRUCTURAL MATERIALS

SPACEBORNE THERMAL IMAGING OF THE EARTH SURFACE: THE TRENDS AND THE DEVELOPMENT PROSPECTS
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.102 The spaceborne thermal imaging of the Earth plays a key role in monitoring natural and anthropogenic processes, such as wildfires and volcanic activity. It is used to measure the surface temperature, assess crop moisture levels, and determine the rock composition. However, the availability and spatial resolution of such data have long been significantly inferior to optical counterparts due to a number of technical difficulties. In recent years, the situation has been changing thanks to the development of small commercial Earth remote sensing spacecraft constellations and the application of new technologies. This article analyzes the current trends in and the prospects for the development of thermal infrared imaging by small satellites plus nighttime optical imaging projects. Particular attention is paid to commercial constellations, such as OTC (OroraTech / Spire Global), HotSat (SatVu / Leonardo), Hydrosat, FireSat (Muon Space), EarthDaily, etc. Their size, orbital parameters, imaging frequency, spectral capabilities, spatial resolution, and payload are investigated. It is shown that most thermal imaging constellations have a dual, civilian and military, purpose. A transition to multispectral imaging in the mid-wave and long-wave infrared ranges and the use of synchronous thermal and optical imaging are observed. Less energy-intensive uncooled sensors (microbolometers) are being introduced. Under development is high-detail nighttime optical imaging by American and Chinese companies’ small satellites with traditional optical Earth observation capabilities. Increasing use is made of artificial intelligence (AI) methods for preliminary data processing, improving spatial resolution, and autonomous anomaly detection directly onboard satellites. Research is in progress in the field of autonomous guidance and attitude control of satellites using AI. REFERENCES 1. Khramov D. O., Pyrozhenko O. O. Optical methods of Earth remote s…
creator: D. O. KHRAMOV
creator: A. I. MASLOVA
creator: O. O. PYROZHENKO
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 102
ending page: 112

ACCOUNTING FOR THE EFFECT OF PULP PARAMETERS WHEN SIMULATING THE FINE SCREENING PROCESS
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.113 Fine screening is an important constituent of magnetite quartzite dressing, whose improvement is largely associated with a further development of the industry. Available mathematical models of dry fine screening allow one to control the process parameters. For wet fine screening, it is necessary to take into account the features of the pulp characteristics effect, which makes this study important. The goal of the work is to determine the effect of the main pulp parameters in developing a model of iron ore screening. As distinct from dry screening, pulp or suspension particle sieving on a hydraulic screen involves the presence of an aqueous medium, whose main characteristic is viscosity. Pulp viscosity is a measure of the internal friction of the suspension, which depends on the concentration, the solid particle size and density, and the viscosity of the liquid phase. It determines the fluidity of the pulp, its ability to transport material particles, and the effect on the process of size separation on the screen. To take into account the features of wet fine screening, the main pulp characteristics are identified and combined into a pulp coefficient. A regression analysis is used to determine the type and value of this coefficient. The level of effect of each of the selected pulp parameters is shown, and the calculated hypersurfaces of the pulp coefficient as a function of the analyzed factors are presented. The form of the pulp coefficient as a function of the pulp characteristics is determined. The adequacy of the obtained screening model is confirmed by a high value of the coefficient of determination R2 = 0.972 and a small value of the standard estimate error SE = 0.00793. The fine screening process was simulated for a stochastic ore pulp inflow specified as an estimated-parameter distribution using Tikhonov’s fine screening model. To determine the pulp characteristics and the pulp coefficient, a regression analysis w…
creator: V. V. NEVZOROV
creator: T. A. OLIINYK
creator: N. P. SYROTKINA
creator: L. V. MUZYKA
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 113
ending page: 122

ON THE RESEARCH RESULTS OF THE SCIENTIFIC SCHOOL AT THE NATIONAL ACADEMY OF SCIENCES OF UKRAINE "DYNAMICS OF SPACE TECHNOLOGY OBJECTS" IN 2021–2025
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.003 This article presents a review of the work carried out from 2021 to 2025 by scientists from the National Academy of Sciences of Ukraine (NAS) representing the "Dynamics of Space Technology Objects" research school. Some of this work concerns a systems analysis of Ukraine's space industry. Research of spacecraft dynamics and systems was conducted in several areas. These areas are: the development of machine learning methods in spacecraft control, optimization of spacecraft controlled motion, systems for remote sensing of the Earth's surface, deorbiting of space debris, a methodology for conceptual design of an industrial space platform, the problem of space service technology and the formation of a paradigm for stabilizing the Earth's climate based on space systems for shading its surface. A multiscale model of any signal/variable based on multiformalism, experience, and consensus management was generalized. The model allows for diversification of computational methods and means of obtaining primary information. A scheme for applying morphological calculations to integrate and generalize primary information was developed. The application of modern information technologies to solve problems of spacecraft (SC) dynamics was considered. It was shown that free open-source software (GMAT, Basilisk, OreKit, etc.) is an effective alternative to proprietary packages for modeling the orbital motion of SC, trajectory optimization, and visualization. An algorithm for preliminary selection of a set of image features used as input information for neural networks was created. This approach allows one to significantly reduce the dimensionality of input data, thereby reducing computational requirements. The advantages of using artificial intelligence methods for space applications were shown. They make it possible to reduce the requirements for control system elements, such as sensors, actuators, to abandon the use of special benches for t…
creator: A. P. ALPATOV
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 3
ending page: 22

FEATURES OF THE MATHEMATICAL SIMULATION OF DYNAMIC PROCESSES IN THE RECONFIGURABLE PROPELLANT FEED HYDRAULIC SYSTEM OF LIQUID-PROPELLANT ROCKET ENGINES
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.023 Hydraulic pipeline systems in liquid-propellant rocket engines (LPREs) are numerous and diverse. In staged-combustion LPREs, use is made of reconfigurable hydraulic systems, in which the propellant component flow directions change during an engine start-up. A reliable engine start-up requires a smooth transition from the start-up propellant supply to the main propellant supply. The objective of this study is to develop an approach to the mathematical simulation of dynamic processes in a branched reconfigurable hydraulic feed system. A methodological framework for modeling dynamic processes in such systems is proposed. It involves determining the frequency responses of several configurations of a hydraulic system realized at different stages of its operation as a distributed-parameter system. The next step is the construction of a lumped-parameter mathematical model with fluid motion and continuity equations in lumped parameters. Lumped compliances are typically introduced in the hydraulic network model at pipeline junctions. Their number and values are selected so that the frequency responses of the distributed- and lumped-parameter models for each hydraulic system configuration may be in agreement within a prescribed accuracy. To demonstrate the proposed approach, a test reconfigurable hydraulic system is considered. Two configurations of the hydraulic system are set off: from the start-up tank to the gas generator and from the pump outlet to the gas generator. For both configurations, frequency responses of the corresponding distributed-parameter systems are determined. A lumped-parameter mathematical model of dynamic processes in the hydraulic system under analysis is developed. The values of the lumped compliances at the network nodes are identified such that the frequency responses of the distributed- and lumped-parameter models are in satisfactory agreement. It is shown that the values of the lumped compliances rema…
creator: O. S. CHERNIAVSKYI
creator: S. I. DOLGOPOLOV
creator: S. A. SHEVCHENKO
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 23
ending page: 33

EXPERIMENTAL METHODS OF SOLID ROCKET PROPELLANT CHARACTERIZATION
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.034 The process of designing a solid-propellant rocket engine is a complex problem. Usually, it is solved by an iterative method, in which the initial data are gradually refined using experimental studies. With a sufficient statistical database, the problem is somewhat simplified because use can be made of the results for a similar engine close to that under development. In any case, the design is completed by engine testing. The cost of each stage depends on the complexity of the engine as a whole, but the most expensive stage is always the engine testing. Because of this, in order to minimize resources, rocket engine developers try to reduce the extent of experimental tryout. In addition to energy characteristics, an important parameter necessary for engine design is the propellant combustion characteristics. The solid rocket propellant burning rate depends on many factors: the propellant type and initial temperature, the combustion chamber pressure, the component particle size, the flight acceleration, the gas speed near the charge surface, etc. Accordingly, these properties are used to regulate the burning rate. Since it is now mathematically very difficult to predict the solid rocket propellant burning rate, various experimental methods are used for these purposes. The goal of the work is to analyze experimental methods of solid rocket propellant characterization at the research stage. Research tests are carried out to study working processes occurring in the engine and its systems. Their study is necessary for the development and use of new propellants, radically new design ideas, and advanced materials and technologies. Research test programs are diverse and usually require new test and measurement methods and means. Therefore, this stage of rocket engine development is more often carried out using not standard equipment, but unique experimental installations or models, which allow one to obtain information on the obje…
creator: S. S. VASYLIV
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 34
ending page: 44

FINITE-ELEMENT ANALYSIS OF THE STRESS AND STRAIN FILED OF THIN FUNCTIONALLY GRADED PLATES WITH A CIRCULAR HOLE UNDER VARIOUS TYPES OF LOADING
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.045 Thin-walled plate-shell structural elements are widely used in various sectors of engineering and the national economy, particularly in the aerospace, oil and gas, and power industries, mechanical engineering, construction, etc. The presence of holes in structures of this type leads to a sharp increase in local stresses, which under certain conditions may lead to destructive processes. This is especially true if they are used under extreme conditions, which is common in various sectors of engineering. Reducing stress concentration near holes in thin-walled structures is a pressing problem in solid mechanics. One way to do this is to use advanced functionally graded materials (FGMs) with specific mechanical properties. A gradient in mechanical properties allows one to control the stress and strain field of structural elements and may contribute to stress reduction near local stress concentrators. This FGM feature significantly increases the strength and reliability of structures as a whole. This paper presents the results of a computer simulation and finite-element analysis of the stress and strain field of thin rectangular FGM plates under various types of loading. The effect of the FGM plate elastic modulus variation law on stress and strain concentration in the vicinity of a hole is investigated. The stress and strain intensity distribution in local stress concentration zones is obtained. Cases of elastic modulus variation in a horizontal and a vertical direction for each of the loading types under consideration are studied. FGM plate heterogeneity parameters are found such that the stress concentration factor can be reduced down to ~19 %. At the same time, a proportional decrease in the strain intensity in the vicinity of the hole is also observed. The FGM plate elastic modulus variation law has a significant effect not only on the magnitude of the stress and strain concentration parameters, but also on the pattern of …
creator: E. L. HART
creator: B. I. TEROKHIN
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 45
ending page: 53

MODAL ANALYSIS OF A HORIZONTAL SHELL STRUCTURE UNDER BLAST LOADING
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.054 This article addresses the problem of modal analysis of a horizontal steel tank with a capacity of 50 m³ on concrete saddle supports. The structure is modeled as a cylindrical shell of length 8.15 m, radius 1.4 m, and wall thickness 5 mm. The geometric model of the tank is presented in a three-dimensional form. To model the horizontal shell, eight-node shell finite elements (SHELL281) are employed. The saddle supports are modeled using three-dimensional twenty-node second-order finite elements (SOLID186). The horizontal shell is reinforced with stiffening beams and a diaphragm. The bottom surfaces of the supports are fixed. Contact interaction between the shell and supports is modeled as well. We use a refined mesh in the contact zones. To model the stiffening beams, nonlinear three-node beam elements based on Timoshenko’s beam theory are utilized. The natural frequencies and mode shapes are computed using the finite-element method. The boundary conditions considered in the modal analysis include the assumption of no contact loss. The calculated modal participation factors show that the first mode plays a dominant role in evaluating dynamic behavior of the structure in the Y-axis direction. This mode is also a torsional one about the vertical Z-axis, thus indicating the possibility of resonance effects under seismic loading. From an energy standpoint, beam elements of the diaphragm exhibit an excessive concentration of specific strain energy; such elements require some reinforcement to prevent resonance-induced excitations. Under blast loading, the extent of structural damage depends on the response rate of the structure to the blast wave. Small, stiff structures respond significantly faster than large ones. When the duration of the blast wave exceeds the natural vibration period of the structure, the critical factor is the overpressure. Conversely, if the blast wave duration is short compared to the natural period, the i…
creator: O. Ye. KUCHERENKO
creator: V. A. BLAZHKO
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 54
ending page: 61

ANALYSIS OF THE ANTIPLANE DEFORMATION OF A CRACKED QUASICRYSTAL WITH CONSIDERATION FOR SURFACE EFFECTS
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.062 The antiplane shear deformation (Mode III) of a linear hexagonal quasicrystal containing an isolated crack under remote uniform loading is investigated taking into account phonon–phason coupling and surface effects within the framework of the Gurtin–Murdoch surface elasticity model. The crack faces are modeled as elastic membranes possessing surface phonon, phason, and coupling constants of their own, which makes it possible to adequately describe size effects at the nano- and submicron scales. Based on the equations of quasicrystal elasticity theory incorporating both phonon and phason fields, a mathematical model of the problem is developed. The boundary conditions on the crack faces, modified by surface energy, lead to a system of singular integro-differential equations with a Cauchy-type kernel. To solve this system, the collocation method with Chebyshev polynomials is applied, thus ensuring a high accuracy and good convergence of the numerical procedure. The numerical analysis performed for a one-dimensional hexagonal quasicrystal shows that accounting for surface elasticity significantly alters the stress and strain field near the crack tip. In contrast to classical fracture mechanics, where a square-root stress singularity occurs, the proposed model predicts finite stresses and strains. Surface elasticity acts as a regularizing mechanism that “smooths” the singularity and introduces a size-dependent response. It is shown that as the crack length increases, the stresses at the crack tip and in its vicinity increase, while the normalized crack opening displacement changes only slightly. For small cracks, surface effects are dominant, whereas with increasing defect size the behavior gradually approaches the classical solution, although it does not coincide with it completely. The results can be used to assess the strength and fracture toughness of quasicrystalline materials taking into account nanoscale effects. The o…
creator: O. M. KLETSKOV
creator: V. V. LOBODA
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 62
ending page: 72

FINITE-ELEMENT SIMULATION OF THE IN-SERVICE STRESS AND STRAIN FIELD OF HIP JOINT ELEMENTS BASED ON COMPUTER TOMOGRAPHY DATA
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.073 The development of innovative human hip arthroplasty technologies and up-to-date designs of endoprostheses, in particular acetabularcomponents, and the improvement of methods to fix them in the acetabular component – hipbone system and surgical techniques made it possible to make extremities fully operable, restore freedom of motion without any pain or discomfort, improve life quality, and readapt patients to work. The current trends in hip arthroplasty are the improvement of existing hip joint endoprosthesis designs and the development of new ones based on the results of biomechanical studies of acetabular component fixation stability and the development of technologies for designing an individual endoprosthesis by constructing virtual 3D hipbone models using computer tomography data with the aim to extend the endoprosthesis service life. Important problems in orthopedy- and traumatology-related biomechanics are the mathematical simulation and the analysis of the behavior of variously designed acetabular components of a hip joint endoprosthesis in conditions of traumatic defects of the acetabulum. The goal of the studies presented in this paper is to develop a finite-element model based on computer tomography data to study the stress and strain field of hip joint elements under service loads and thoroughly analyze the contact interaction of the femoral head with the acetabulum. The paper presents an algorithm for constructing a geometrical model based on computer tomography data to study the hip joint strength and a 3D geometrical model developed by that algorithm, which includes the sacrum, the ilium, the pubis, the acetabulum, and the femoral head. Based on that model, a finite-element model is developed to study the stress and strain field of hip joint elements under service loads and thoroughly analyze the contact interaction of the femoral head with the acetabulum. The proposed model may be used in the development o…
creator: D. V. HOROBETS
creator: M. B. SOBOLEVSKA
creator: O. Ye. LOSKUTOV
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 73
ending page: 85

DARRIEUS ROTOR SPEED CONTROL BY SIMULTANEOUS CHANGES IN THE ROTOR CONFIGURATION AND THE GENERATOR BRAKING TORQUE
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.086 In recent decades, the "green" power industry has been developing rapidly. The growing interest in generating "green" power has led to a sharp increase in the number of operating systems, among which vertical-axis wind turbines (WT) occupy a significant place. Along with a number of advantages, the most difficult issues when using vertical-axis WTs are ensuring their self-starting and increasing efficiency. Due to the rotation of the turbine about a vertical axis, the aerodynamics of the turbine is more complex than that of a comparable horizontal-axis wind turbine, and knowledge and understanding of these turbines remain far from complete. The introduction of any approaches to improving the properties of a WT as a whole requires an in-depth study and coordination of the operation of its elements to ensure the compatibility of the operation of individual components. The proposed work considers a system to control the rotation of the Darrieus rotor of vertical-axis wind turbines, which consists of three control loops: two loops for changing the length of the blades and traverses and a loop for controlling the braking torque of the permanent magnet generator. The use of a generator to control the rotation of the rotor of a wind turbine is a traditional means of ensuring small deviations in the rotation speed about the point of maximum power for the current wind flow speed. The use of permanent magnet synchronous generators for this purpose, which have a number of useful properties, is quite a new line in the design of control systems. The work considers the features of the dynamics and control of the rotor rotation speed of vertical-axis wind turbines as a control object, which is stabilized by a simultaneous change in the configuration of the wind turbine rotor and the braking torque of the permanent magnet generator. The simultaneous use of the three stabilization channels contributes to a greater adaptation of the turbin…
creator: S. V. TARASOV
creator: O. N. MOLOTKOV
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 86
ending page: 101

STUDY OF THE PERFORMANCE OF PLANAR ANTENNA ARRAYS AS A FUNCTION OF THEIR TOPOLOGY AND THE PROPERTIES OF THEIR STRUCTURAL MATERIALS
type: item
description: DOI: https://doi.org/10.15407/itm2026.01.123 The rapid development of unmanned aerial vehicles and the extension of their range of application increase requirements for radar systems, in particular in terms of detecting small-sized targets with a low effective scattering area in a complex interfering environment. One of the promising engineering solutions for such systems is the use of planar antenna arrays, which provide electronic control of the radiation pattern, a high scanning speed, and design scalability. The goal of this work is to assess the effect of the number of radiating elements, the relative dielectric constant, and the physical thickness of the dielectric substrate on the electrodynamic characteristics and radiation parameters of planar antenna arrays. The study analyzes the radiation patterns, the gain, the energy potential, and the operating frequency band at different numbers of array elements. The work is based on numerical simulation in the CST Studio Suite environment using the finite integral method. Use is made of the parameterization of the emitter dimensions for resonance correction and the linear extrapolation method for estimating the characteristics of many-element arrays. The work investigates the electrodynamic characteristics of planar antenna arrays built on the basis of rectangular microstrip radiating elements with a corporate feed system. A 2×2 subarray was chosen as the basic element, which was subsequently scaled to 4×4 and 8×8 element configurations. Particular attention is paid to the effect of the dielectric substrate parameters, in particular its relative permittivity and physical thickness, on the radiation characteristics of the array. It is shown that the use of the Rogers 5880 dielectric substrate of standard thickness provides an optimal balance between radio technical characteristics, mechanical rigidity, and manufacturability. A stable trend is found to gain increase and main lobe narrowing with array scaling and to f…
creator: І. V. HRYMALIUK
rights: Copyright (c) 2026 Technical Mechanics
date: 2026-03-31
publication date: 2026-03-31
number: 1
starting page: 123
ending page: 136