Igor Kovtun - Academia.edu (original) (raw)

Papers by Igor Kovtun

MATEC web of conferences, 2021

The article presents the results of works on the analysis of the possibility of using force measu... more The article presents the results of works on the analysis of the possibility of using force measurements to determine the state of the machining process, both in relation to the phenomena occurring during machining and the workpiece itself compared to acoustic emission signal (AE). The research and analyzes were carried out for the commonly used material removal processes of objects; turning, milling, grinding and drilling. Various materials were processed-metal alloy Hardox 400 as well as fiber composite materials (GFRP-Glass Fiber Reinforced Polymer) and polymer construction material RenShape® BM5035 with various structures. As a result of the conducted analyzes, it was determined that the forces generated in the machine tool-holder-workpiece-tool layout can constitute a good diagnostic signal, on the basis of which it is possible to conclude about the state of the process.

Vìsnik Hmelʹnicʹkogo nacìonalʹnogo unìversitetu, May 26, 2022

Представленим в даній роботі науковим результатом є подальший розвиток застосування теорії Ламе-Г... more Представленим в даній роботі науковим результатом є подальший розвиток застосування теорії Ламе-Гадоліна про взаємодію складених товстостінних циліндрів для оцінки міцності електронних компонентів, що мають форму тіл обертання та оточуючого шару компаунду при довільній формі заливки останнього в умовах термоудару. В межах осесиметричної задачі проведена оцінка напружено-деформованого стану системи електронний компонент-компаунд при перепаді температур, завдяки чому виявлено закономірність виникнення максимальних загальних радіальних, окружних та осьових напружень в залежності від їх радіального розподілу та режиму температурного навантаження. Здійснено розрахунок напружень в резисторі С2-29В герметизованому компаундом марки ЕЗК-25 в складі гермомодуля при сталому перепаді температур. Запропоновано експериментальний спосіб визначення граничних напружень в електронних компонентах герметизованих компаундом. Представлені ефективні технологічні методи захисту електронних компонентів герметизованих компаундом. Ключові слова: герметизований електронний модуль, електронний компонент, компаунд, міцність, напружено-деформований стан

Herald of Khmelnytskyi National University, 2021

The material presented in the article contains the results theoretical research, in terms of rese... more The material presented in the article contains the results theoretical research, in terms of research and implementation in production technological design methods for the operational construction of mathematical models’ assembly processes of electronic devices and the choice of optimal parameters of their parts. This technique is based on the statistical principles of active planned experiment, which are currently widely used in various fields of science and technology. The use of these principles, in contrast to traditional methods of conducting a passive experiment and processing the results obtained in this case, allows to drastically reduce the time and material costs for a reliable mathematical description of complex physical laws that underlie the processes of compiling modern electronic devices and choosing the parameters of the parts included in them. The proposed methodology provides for a modification of the principles of an active planned experiment, which can be used wh...

2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO), 2018

The paper represents identification of natural frequency and form of oscillation for the main con... more The paper represents identification of natural frequency and form of oscillation for the main construction elements of the electronic packages such as printed circuit boards, walls of the cases and other bearing parts subjected to vibration and shocks during operation. The current study is focused on using elements of plate bending theory, in which main boards, case walls and other planar rectangular structures are considered as equivalent homogeneous plates, in order to estimate their natural frequencies and forms of free cross oscillations and hence to identify their possible resonances with purpose to avoid them and correspondent dangerous operational modes. The significant attention was paid to the experimental research of dynamic characteristics conducted by using experimental setup created on the base of reverse and direct piezoelectric effects and also the shaker with vibration test cross appliance, representing results in form of Chladni figures and amplitude frequency response.

Journal of Physics: Conference Series, 2021

Mathematical model for dynamic force analysis of printed circuit boards has been designed to calc... more Mathematical model for dynamic force analysis of printed circuit boards has been designed to calculate dynamic deformations and stresses in printed circuit boards and assess their dynamic strength and rigidity. The represented model describes a printed circuit board as a separate oscillatory system, which is simulated as prismatic beam set on two oscillating supports. Simulation and assessment of stress and deflection in printed circuit boards and obtaining their amplitude frequency responses provided recommendations, which ensure strength and stiffness of printed circuit boards subjected to dynamic loads.

Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, 2019

The paper represents technical diagnostics of printed circuit boards in particular their solder j... more The paper represents technical diagnostics of printed circuit boards in particular their solder joints performed by commonly used through-hole and surface mount technologies. Operation and technology cause mechanical interactions and forces between substrate of printed circuit board and electronic components. Such tensile, shear, bending or torque forces transmit through the contact joints, which appear to be the weakest links in the assembly. The experimental research was conducted by mechanical tensile and pure bending tests followed by using method of acoustic emission. Conducted tests demonstrated considerable sensitivity and applicability for the method of acoustic emission to detect defects and possibly to assess the ultimate strength of solder joints in nondestructive diagnostics performed under forces long before the final failure. In order to minimize errors while measuring small loads in tensile tests of ceramic capacitors the special appliance was designed. The experiment was conducted to verify the overheating effect to ultimate load of the solder joints. Surface mount technology for ceramic capacitors has been optimized by introducing high temperature preheating mode that improves adherence to the contact pads and increases tensile strength, what was also confirmed by acoustic emission analysis. The pure bending appliance was designed to provide instant monitoring of all solder joints by equal testing stress. By conducted pulsing test cycles the total count was identified as the most informative parameter of acoustic emission that correlates with types of defects and ultimate strength of the solder joints. The planar location model has been developed by the idea of remote detection of acoustic emission through the volume of homogeneous medium such as water, unlike detecting acoustic emission on the surface of printed circuit board where acoustic emission signal is likely to be distorted or even lost. Using method of acoustic emission and pure bending cycling test the method for technical diagnostics of solder joints has been designed. The results represented in the paper contribute to design and technology improvement in radioelectronics .

MEASURING AND COMPUTING DEVICES IN TECHNOLOGICAL PROCESSES

Стаття присвячена розробленню методик неруйнівної діагностики нероз’ємних елементів конструкцій е... more Стаття присвячена розробленню методик неруйнівної діагностики нероз’ємних елементів конструкцій електронної техніки, зокрема їх паяним та зварним з’єднанням. Методики неруйнівної діагностики міцності і герметичності побудовані на основі акустико-емісійного і електротензометричного методів вимірювання застосовані в умовах механічного, температурного та пневматичного навантаження. Випробування на міцність паяних з’єднань наскрізного та поверхневого монтажу двох-вивідних електронних компонентів в критичних умовах напружено-деформованого стану під дією простих видів механічного навантаження на відрив та розтяг та випробування паяних з’єднань друкованих плат навантаженням, яке створює напружено-деформований стан, що зустрічається в процесі експлуатації, за схемою навантаження на чистий згин в режимі циклічного пульсуючого навантаження показали зниження міцності та можливість використання параметрів акустичної емісії в якості діагностичних для виявлення дефектів та оцінки міцності паяних ...

Herald of Khmelnytskyi National University. Technical sciences

Electronic equipment of aircraft during operation is exposed to vibrations with a frequency of 20... more Electronic equipment of aircraft during operation is exposed to vibrations with a frequency of 20-2000 Hz and a vibration acceleration of up to 20g. Almost half of all failures of on-board equipment are caused by the negative impact of vibration. For effective vibration protection of the equipment during its design, a vibration analysis is carried out, recognizing resonance modes. The difficulty of modeling vibration processes in printed circuit boards lies in the deviation of calculated values of critical frequencies and values obtained experimentally with the help of shakers. The main reasons for this in the known analytical methods are the impossibility of fully accurate consideration of the concentrated masses and elastic-damping characteristics of individual electronic components of the board, its fasteners and device cases, which, in turn, leads to the appearance of coupled oscillations. The paper presents the results of vibration analysis by well-known analytical methods, num...

Journal of Vibroengineering, 2013

The paper represents mathematical model and formulas developed for project calculations which are... more The paper represents mathematical model and formulas developed for project calculations which are applied to sealed electronic units and provide assessing strength of passive electronic components having revolution shape (capacitors, resistors, diodes, pins, etc.). The stress calculation has been produced for materials of resistor and compound in the temperature interval (from –60 to +70°C) along the radius of resistor and compound.

2017 IEEE First Ukraine Conference on Electrical and Computer Engineering (UKRCON), 2017

The paper demonstrates that vibration sustained by electronic packages while their operation or t... more The paper demonstrates that vibration sustained by electronic packages while their operation or tests cannot be characterized by vibration measured either on their supporting base or on the shaker transmitting this vibration. The theoretical model of the oscillating system representing electronic unit installed on the support subjected to vibration is described. Vibration transmission from the shaker to the tested electronic unit is explained as the complex problem to solve. The experimental measurement of vibration conducted inside of tested electronic units verified significant difference in amplitude of vibrations transmitted inside the units and external vibrations that units are exposed to.

2019 International Conference on Information and Telecommunication Technologies and Radio Electronics (UkrMiCo)

The paper represents stress assessment of electronic packages with complete compound encapsulatio... more The paper represents stress assessment of electronic packages with complete compound encapsulation subjected to thermal impacts. The stress calculation scheme for the joint of electronic component and surrounding layer of compound is brought to axially symmetric problem of two joined thick-walled cylinders and described by using Lame-Gadolin theory. The mathematical model was obtained by solving statically indeterminate problem. Formulas for radial and tangential stress and contact pressure calculation were obtained for stationary thermal condition. Non-stationary problem of thermal conduction in the sealed package was solved. The problem of non-stationary radial distribution of temperature in electronic component and compound was solved. Calculation formulas were optimized for the ultimate thermal impact on the encapsulated package.

2019 IEEE 39th International Conference on Electronics and Nanotechnology (ELNANO)

This paper represents analysis of principles providing maximally reliable delay estimation of sig... more This paper represents analysis of principles providing maximally reliable delay estimation of signal synchronization devices in telecommunication. Clock synchronization schemes on the base of stochastic models, graph-analytic interpretation, analytical functional description and their parameters selection in case of real complex hindrance are analyzed. Dependences between dispersion of maximally reliable estimation of synchronization devices and signal to noise ratio (SNR) are represented. Analytical expressions and dependences are obtained for deviation of synchronization error with respect to SNR at the output of discriminator. Diagrams of state are formed for assessment of digital synchronization device in case of error state. Average slip time of synchronization is calculated with respect to SNR.

2018 International Conference on Information and Telecommunication Technologies and Radio Electronics (UkrMiCo), 2018

The paper represents stress estimation for electronic packages with complete compound encapsulati... more The paper represents stress estimation for electronic packages with complete compound encapsulation subjected to thermal impacts. The Lame-Gadolin theory that considers interaction of compound thick-walled cylinders in form of axially symmetric problem has been substantiated for stress calculations in electronic components represented as the solids of revolution surrounded by the layer of compound and subjected to simultaneous action of pressure and temperature. Statically indeterminate problem was solved with considerations in the material properties and compatibility in deformations in order to define radial, tangential stresses and strain in both electronic elements and compound. Calculation formulas were optimized for the case of stabilized temperature drop, which represent the ultimate thermal impact on the encapsulated package.

MATEC Web of Conferences, 2021

Mathematical modeling and experimental research represented in this paper is aimed at dynamic for... more Mathematical modeling and experimental research represented in this paper is aimed at dynamic force analysis of circuit cards in order to eliminate or reduce dynamic stress and deflection to an acceptable level and to provide strength and reliability in design of circuit card assemblies subjected to vibration. In conditions when viscous friction forces are negligible and viscous friction dampers, such as liquid dampers, cannot be used reduction of oscillation amplitude in critical frequencies was proposed by creating dry friction damper. On the base of mathematical model, the method for reducing dynamic stress and deflection in critical section of circuit cards in resonance conditions has been developed by inserting additional elastic and dissipation joint introduced by dry friction damper. The dry friction damper device is introduced in three variants of design. The effectiveness of dry friction damper is characterized by its elastic and damping characteristics and especially by th...

2021 IEEE International Conference on Information and Telecommunication Technologies and Radio Electronics (UkrMiCo), 2021

The paper represents analysis and control of deformations and stresses in small-size structural p... more The paper represents analysis and control of deformations and stresses in small-size structural parts in electronic packages subjected to static and dynamic mechanical, thermal and pressure impacts by using methods of mathematical modeling and experimental research by electrotensometry, acoustic emission, vibration analysis and high-speed video-shooting. Mathematical models have been designed for stress and strain estimation in structural parts of circuit card assemblies subjected to static mechanical forces; for thermal stress and strain estimation in sealed packages; for dynamic stress and deflection calculation in complex structures of electronic packages. Conducted research benefits from introducing methods ensuring strength and stiffness condition for complex structures of electronic packages.

2017 International Conference on Information and Telecommunication Technologies and Radio Electronics (UkrMiCo), 2017

The paper represents strength research of solder joints produced on printed circuit boards by thr... more The paper represents strength research of solder joints produced on printed circuit boards by through-hole and surface mount technologies. The research methods involve static mechanical tensile and bend tests and acoustic emission method application with simultaneous monitoring both mechanical characteristics and acoustic emission parameters in order to find their correlation. On the base of conducted experiments method for nondestructive strength diagnostics of solder joints on printed circuit boards by using pure bending cycling tests and method of acoustic emission has been developed.