Research

19 pages, 10224 KiB

Open AccessArticle

Analysis of Effectiveness of Combined Surface Treatment Methods for Structural Parts with Holes to Enhance Their Fatigue Life

by Olexander Grebenikov, Andrii Humennyi, Serhii Svitlychnyi, Vasyl Lohinov and Valerii Matviienko

Computation 2024, 12(1), 8; https://doi.org/10.3390/computation12010008 - 08 Jan 2024

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Abstract

The typical and most widespread stress concentrators in the lower wing panels of aircraft are the drain holes located on the stringer vertical ribs. These are prime sources for the initiation and development of fatigue cracks, which lead to early failure of the [...] Read more.

The typical and most widespread stress concentrators in the lower wing panels of aircraft are the drain holes located on the stringer vertical ribs. These are prime sources for the initiation and development of fatigue cracks, which lead to early failure of the wing structure. Therefore, improving fatigue life in these critical areas is one of the significant issues for research. Two combined methods of surface plastic treatment in the location around drain holes are discussed in this paper. Using the finite element method and ANSYS software, we created a finite element model and obtained nonlinear solution results in the case of tension in a plate with three holes. In addition, the development of residual stress due to the surface plastic treatment of the hole-adjacent areas was taken into account. In this paper, it is shown that after surface treatment of the corresponding areas of the holes, residual stress, which exceeds the yield stress for the plate material, is induced. When combined with alternative tensile stress, these reduce the amplitude of the local stresses, thus increasing the number of stress cycles before failure. The benefits of this technology were confirmed by fatigue test results, which include the fatigue failure types of the plates. Graphs showing the impact of applicable surface treatment combined methods on the number of cycles to failure were also plotted. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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31 pages, 7813 KiB

Open AccessArticle

Agile Software Development Lifecycle and Containerization Technology for CubeSat Command and Data Handling Module Implementation

by Oleksandr Liubimov, Ihor Turkin, Vladimir Pavlikov and Lina Volobuyeva

Computation 2023, 11(9), 182; https://doi.org/10.3390/computation11090182 - 14 Sep 2023

Cited by 1 | Viewed by 1288

Abstract

As a subclass of nanosatellites, CubeSats have changed the game’s rules in the scientific research industry and the development of new space technologies. The main success factors are their cost effectiveness, relative ease of production, and predictable life cycle. CubeSats are very important [...] Read more.

As a subclass of nanosatellites, CubeSats have changed the game’s rules in the scientific research industry and the development of new space technologies. The main success factors are their cost effectiveness, relative ease of production, and predictable life cycle. CubeSats are very important for training future engineers: bachelor’s and master’s students of universities. At the same time, using CubeSats is a cost-effective method of nearest space exploration and scientific work. However, many issues are related to efficient time-limited development, software and system-level quality assurance, maintenance, and software reuse. In order to increase the flexibility and reduce the complexity of CubeSat projects, this article proposes a “hybrid” development model that combines the strengths of two approaches: the agile-a-like model for software and the waterfall model for hardware. The paper proposes a new computing platform solution, “Falco SBC/CDHM”, based on Microchip (Atmel) ATSAMV71Q21 with improved performance. This type of platform emphasizes low-cost space hardware that can compete with space-grade platforms. The paper substantiates the architecture of onboard software based on microservices and containerization to break down complex software into relatively simple components that undergraduates and graduates can handle within their Master’s studies, and postgraduates can use for scientific space projects. The checking of the effectiveness of the microservice architecture and the new proposed platform was carried out experimentally, involving the time spent on executing three typical algorithms of different algorithmic complexities. Algorithms were implemented using native C (Bare-metal) and WASM3 on FreeRTOS containers on two platforms, and performance was measured on both “Falco” and “Pi Pico” by Raspberry. The experiment confirmed the feasibility of the complex application of the “hybrid” development model and microservices and container-based architecture. The proposed approach makes it possible to develop complex software in teams of inexperienced students, minimize risks, provide reusability, and thus increase the attractiveness of CubeSat student projects. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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16 pages, 6102 KiB

Open AccessArticle

The Use of IoT for Determination of Time and Frequency Vibration Characteristics of Industrial Equipment for Condition-Based Maintenance

by Ihor Turkin, Viacheslav Leznovskyi, Andrii Zelenkov, Agil Nabizade, Lina Volobuieva and Viktoriia Turkina

Computation 2023, 11(9), 177; https://doi.org/10.3390/computation11090177 - 05 Sep 2023

Viewed by 1081

Abstract

The subject of study in this article is a method for industrial equipment vibration diagnostics that uses discrete Fourier transform and Allan variance to increase precision and accuracy of industrial equipment vibration diagnostics processes. We propose IoT-oriented solutions based on smart sensors. The [...] Read more.

The subject of study in this article is a method for industrial equipment vibration diagnostics that uses discrete Fourier transform and Allan variance to increase precision and accuracy of industrial equipment vibration diagnostics processes. We propose IoT-oriented solutions based on smart sensors. The primary objectives include validating the practicality of employing platform-oriented technologies for vibro-diagnostics of industrial equipment, creating software and hardware solutions for the IoT platform, and assessing measurement accuracy and precision through the analysis of measurement results in both time and frequency domains. The IoT system architecture for industrial equipment vibration diagnostics consists of three levels. At the autonomous sensor level, vibration acceleration indicators are obtained and transmitted via a BLE digital wireless data transmission channel to the second level, the hub, which is based on a BeagleBone single-board microcomputer. The computing power of BeagleBone is sufficient to work with artificial intelligence algorithms. At the third level of the server platform, the tasks of diagnosing and predicting the state of the equipment are solved, for which the Dictionary Learning algorithm implemented in the Python programming language is used. The verification of the accuracy and precision of the vibration diagnostics system was carried out on the developed stand. A comparison of the expected and measured results in the frequency and time domains confirms the correct operation of the entire system. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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31 pages, 8632 KiB

Open AccessArticle

A Software Verification Method for the Internet of Things and Cyber-Physical Systems

by Yuriy Manzhos and Yevheniia Sokolova

Computation 2023, 11(7), 135; https://doi.org/10.3390/computation11070135 - 07 Jul 2023

Viewed by 945

Abstract

With the proliferation of the Internet of Things devices and cyber-physical systems, there is a growing demand for highly functional and high-quality software. To address this demand, it is crucial to employ effective software verification methods. The proposed method is based on the [...] Read more.

With the proliferation of the Internet of Things devices and cyber-physical systems, there is a growing demand for highly functional and high-quality software. To address this demand, it is crucial to employ effective software verification methods. The proposed method is based on the use of physical quantities defined by the International System of Units, which have specific physical dimensions. Additionally, a transformation of the physical value orientation introduced by Siano is utilized. To evaluate the effectiveness of this method, specialized software defect models have been developed. These models are based on the statistical characteristics of the open-source C/C++ code used in drone applications. The advantages of the proposed method include early detection of software defects during compile-time, reduced testing duration, cost savings by identifying a significant portion of latent defects, improved software quality by enhancing reliability, robustness, and performance, as well as complementing existing verification techniques by focusing on latent defects based on software characteristics. By implementing this method, significant reductions in testing time and improvements in both reliability and software quality can be achieved. The method aims to detect 90% of incorrect uses of software variables and over 50% of incorrect uses of operations at both compile-time and run-time. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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15 pages, 5427 KiB

Open AccessArticle

Simulation of Multi-Phase Flow to Test the Effectiveness of the Casting Yard Aspiration System

by Serghii Lobov, Yevhen Pylypko, Viktoriya Kruchyna and Ihor Bereshko

Computation 2023, 11(6), 121; https://doi.org/10.3390/computation11060121 - 20 Jun 2023

Viewed by 1037

Abstract

The metallurgical industry is in second place among all other industries in terms of emissions into the atmosphere, and air pollution is the main cause of environmental problems arising from the activities of metallurgical enterprises. In some existing systems for localization, in the [...] Read more.

The metallurgical industry is in second place among all other industries in terms of emissions into the atmosphere, and air pollution is the main cause of environmental problems arising from the activities of metallurgical enterprises. In some existing systems for localization, in the trapping and removal of dust emissions from tapholes and cast-iron gutters of foundries, air flow parameters may differ from the optimal ones for solving aspiration problems. The largest emissions are observed in the area of the taphole (40–60%) and from the ladles during their filling (35–50%). In this paper, it is proposed to consider a variant of the blast furnace aspiration system with the simultaneous supply of a dust–gas–air mixture from two-side smoke exhausters and two upper hoods with two simultaneously operating tapholes, that is, when the blast furnace operates in the maximum emissions mode. This article proposes an assessment of the effectiveness of the modernized blast furnace aspiration system using computer CFD modeling, where its main parameters are given. It is shown that the efficiency of dust collection in the proposed system is more than 90%, and the speed of the gas–dust mixture is no lower than 20 m/s, which prevents gravitational settling on the walls. The distribution fields of temperatures and velocities are obtained for further engineering analysis and the possible improvement of aspiration systems. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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14 pages, 9442 KiB

Open AccessArticle

Stress-Strained State of the Thrust Bearing Disc of Hydrogenerator-Motor

by Oleksii Tretiak, Dmitriy Kritskiy, Igor Kobzar, Mariia Arefieva, Volodymyr Selevko, Dmytro Brega, Kateryna Maiorova and Iryna Tretiak

Computation 2023, 11(3), 60; https://doi.org/10.3390/computation11030060 - 16 Mar 2023

Cited by 2 | Viewed by 1267

Abstract

In this article, the main causes of vibration in the thrust bearing of hydrogenerator motors rated 320 MW are considered. The main types of internal and surface defects that appear on the working surface of the thrust bearing disc during long-term operation are [...] Read more.

In this article, the main causes of vibration in the thrust bearing of hydrogenerator motors rated 320 MW are considered. The main types of internal and surface defects that appear on the working surface of the thrust bearing disc during long-term operation are considered. A method of three-dimensional modeling of such defects is presented, and an assessment of the stress-strain state of the heel disc is proposed, taking into account the main forces acting on the working surface using the finite element method. An analysis of the possible further operation of discs with similar defects, in accordance with the technical requirements, is carried out, and we consider ways to eliminate them. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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11 pages, 641 KiB

Open AccessArticle

Research on Scientific Directions for Flying Cars at the Preliminary Design Stage

by Andrii Humennyi, Liliia Buival and Zeyan Zheng

Computation 2023, 11(3), 58; https://doi.org/10.3390/computation11030058 - 10 Mar 2023

Viewed by 3376

Abstract

This article was written to investigate the research on the scientific directions for flying cars at the preliminary design stage to provide a rationale for the choice of scientific research in the area of flying cars. At present, the population of the Earth [...] Read more.

This article was written to investigate the research on the scientific directions for flying cars at the preliminary design stage to provide a rationale for the choice of scientific research in the area of flying cars. At present, the population of the Earth is gradually increasing, and traffic congestion will become a common phenomenon in cities in the future. This work used the methods of theoretical and statistical analysis to form an overall picture of this area of research. We researched the statistical data analysis conducted by scientists who dealt with flying cars and the associated issues. We gave a rationale for the choice of the object of scientific research, which is flying cars. People can read this information to have a starting point in their understanding of flying car design. This analysis of famous scientific works provides possible scientific directions that the research can take with respect to designing a flying car that combines the advantages of an airplane and a car and can take off and land on a normal highway for a short distance, as well as help people reach their destination quickly and easily. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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16 pages, 5136 KiB

Open AccessArticle

Algorithm for Determining Three Components of the Velocity Vector of Highly Maneuverable Aircraft

by Volodymyr Pavlikov, Eduard Tserne, Oleksii Odokiienko, Nataliia Sydorenko, Maksym Peretiatko, Olha Kosolapova, Ihor Prokofiiev, Andrii Humennyi and Konstantin Belousov

Computation 2023, 11(2), 35; https://doi.org/10.3390/computation11020035 - 15 Feb 2023

Cited by 1 | Viewed by 1346

Abstract

We developed a signal processing algorithm to determine three components of the velocity vector of a highly maneuverable aircraft. We developed an equation of the distance from an aircraft to an underlying surface. This equation describes a general case of random spatial aircraft [...] Read more.

We developed a signal processing algorithm to determine three components of the velocity vector of a highly maneuverable aircraft. We developed an equation of the distance from an aircraft to an underlying surface. This equation describes a general case of random spatial aircraft positions. Particularly, this equation considers distance changes according to an aircraft flight velocity variation. We also determined the relationship between radial velocity measured within the radiation pattern beam, the signal frequency Doppler shift, and the law of the range changing within the irradiated surface area. The models of the emitted and received signals were substantiated. The proposed equation of the received signal assumes that a reflection occurs not from a point object, but from a spatial area of an underlying surface. It fully corresponds to the real interaction process between an electromagnetic field and surface. The considered solution allowed us to synthesize the optimal algorithm to estimate the current range and three components

{V_{x}, V_{y}, V_{z}}

of the aircraft’s velocity vector

\vec{V}

. In accordance with the synthesized algorithm, we propose a radar structural diagram. The developed radar structural diagram consists of three channels for transmitting and receiving signals. This number of channels is necessary to estimate the full set of the velocity and altitude vector components. We studied several aircraft flight trajectories via simulations. We analyzed straight-line uniform flights; flights with changes in yaw, roll, and attack angles; vertical rises; and landings on a glide path and lining up with the correct yaw, pitch, and roll angles. The simulation results confirmed the correctness of the obtained solution. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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15 pages, 6881 KiB

Open AccessArticle

Numerical Assessment of Terrain Relief Influence on Consequences for Humans Exposed to Gas Explosion Overpressure

by Yurii Skob, Sergiy Yakovlev, Kyryl Korobchynskyi and Mykola Kalinichenko

Computation 2023, 11(2), 19; https://doi.org/10.3390/computation11020019 - 30 Jan 2023

Cited by 2 | Viewed by 1256

Abstract

This study aims to reconstruct hazardous zones after the hydrogen explosion at a fueling station and to assess an influence of terrain landscape on harmful consequences for personnel with the use of numerical methods. These consequences are measured by fields of conditional probability [...] Read more.

This study aims to reconstruct hazardous zones after the hydrogen explosion at a fueling station and to assess an influence of terrain landscape on harmful consequences for personnel with the use of numerical methods. These consequences are measured by fields of conditional probability of lethal and ear-drum injuries for people exposed to explosion waves. An “Explosion Safety^®” numerical tool is applied for non-stationary and three-dimensional reconstructions of the hazardous zone around the epicenter of the explosion of a premixed stoichiometric hemispheric hydrogen cloud. In order to define values of the explosion wave’s damaging factors (maximum overpressure and impulse of pressure phase), a three-dimensional mathematical model of chemically active gas mixture dynamics is used. This allows for controlling the current pressure in every local point of actual space, taking into account the complex terrain. This information is used locally in every computational cell to evaluate the conditional probability of such consequences for human beings, such as ear-drum rupture and lethal outcome, on the basis of probit analysis. To evaluate the influence of the landscape profile on the non-stationary three-dimensional overpressure distribution above the Earth’s surface near the epicenter of an accidental hydrogen explosion, a series of computational experiments with different variants of the terrain is carried out. Each variant differs in the level of mutual arrangement of the explosion epicenter and the places of possible location of personnel. The obtained results indicate that any change in working-place level of terrain related to the explosion’s epicenter can better protect personnel from the explosion wave than evenly leveled terrain, and deepening of the explosion epicenter level related to working place level leads to better personnel protection than vice versa. Moreover, the presented coupled computational fluid dynamics and probit analysis model can be recommended to risk-managing experts as a cost-effective and time-saving instrument to assess the efficiency of protection structures during safety procedures. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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16 pages, 5864 KiB

Open AccessArticle

Statistical Theory of Optimal Stochastic Signals Processing in Multichannel Aerospace Imaging Radar Systems

by Valeriy Volosyuk and Semen Zhyla

Computation 2022, 10(12), 224; https://doi.org/10.3390/computation10120224 - 18 Dec 2022

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Abstract

The work is devoted to solving current scientific and applied problems of the development of radar imaging methods. These developments are based on statistical theory of optimal signal processing. These developments allow researchers to create coherent high-resolution information-enriched images as well as incoherent [...] Read more.

The work is devoted to solving current scientific and applied problems of the development of radar imaging methods. These developments are based on statistical theory of optimal signal processing. These developments allow researchers to create coherent high-resolution information-enriched images as well as incoherent images. These methods can be practically applied in multichannel aerospace radars through the proposed programs and algorithms. Firstly, the following models of stochastic signals at the output of multichannel registration regions of scattered electro-magnetic fields, internal noise, and observation equations are developed and their statistical characteristics investigated. For the considered models of observation equations, the likelihood functional is defined. This definition is an important stage in optimizing spatial and temporal signal processing. These signals are distorted by internal receiver noises in radar systems. Secondly, by synthesising and analysing methods of measuring a radar cross section, the problem of incoherent imaging by aerospace radars with planar antenna array is solved. Thirdly, the obtained optimal mathematical operations are physically interpreted. The proposed interpretation helps to implement a quasi-optimal algorithm of radar cross section estimation in aerospace radar systems. Finally, to verify the proposed theory, a semi-natural experiment of real radio holograms processing was performed. These radio holograms are digital recordings of spatial and temporal signals by an airborne synthetic aperture radar (SAR) system. The results of the semi-natural experiment are presented and analysed in the paper. All the calculations, developments and results in this paper can be applied to new developments in areas such as remote sensing or non-destructive testing. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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20 pages, 2783 KiB

Open AccessArticle

Statistical Theory of Optimal Functionally Deterministic Signals Processing in Multichannel Aerospace Imaging Radar Systems

by Valeriy Volosyuk and Semen Zhyla

Computation 2022, 10(12), 213; https://doi.org/10.3390/computation10120213 - 03 Dec 2022

Viewed by 1599

Abstract

The theory of the optimal formation of coherent and incoherent images is developed using the foundations of the statistical theory of optimization of radio engineering information-measuring systems. The main operations necessary for synthesizing optimal methods of spatio-temporal processing of functionally deterministic signals in [...] Read more.

The theory of the optimal formation of coherent and incoherent images is developed using the foundations of the statistical theory of optimization of radio engineering information-measuring systems. The main operations necessary for synthesizing optimal methods of spatio-temporal processing of functionally deterministic signals in on-board radio imaging radars with antenna arrays are shown. Models of radio engineering signals and noise have been developed. The statistical and correlation characteristics of spatio-temporal signals and noises in the area of their observation by antenna systems have been investigated. The technique for estimating the limiting errors of the measured characteristics of the studying media is presented. Using the developed theory, a new method for high-resolution radar imaging of the surface from a wide swath was obtained. This method has a new optimal observation mode combining the advantages of several terrain observation modes and fully complies with modern trends in the creation of cognitive radars with the possibility of restructuring the antenna pattern in space and adaptive receiving of reflected signals. The principles of construction and algorithmic support of high-precision airborne radars with an extended observation area are formulated. The effectiveness of the obtained results is investigated by simulation, taking into account the phenomenological approach to the description of electromagnetic fields and coherent images. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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12 pages, 1709 KiB

Open AccessArticle

Detection of Shoplifting on Video Using a Hybrid Network

by Lyudmyla Kirichenko, Tamara Radivilova, Bohdan Sydorenko and Sergiy Yakovlev

Computation 2022, 10(11), 199; https://doi.org/10.3390/computation10110199 - 06 Nov 2022

Cited by 4 | Viewed by 4120

Abstract

Shoplifting is a major problem for shop owners and many other parties, including the police. Video surveillance generates huge amounts of information that staff cannot process in real time. In this article, the problem of detecting shoplifting in video records was solved using [...] Read more.

Shoplifting is a major problem for shop owners and many other parties, including the police. Video surveillance generates huge amounts of information that staff cannot process in real time. In this article, the problem of detecting shoplifting in video records was solved using a classifier, which was a hybrid neural network. The hybrid neural network included convolutional and recurrent ones. The convolutional network was used to extract features from the video frames. The recurrent network processed the time sequence of the video frames features and classified the video fragments. In this work, gated recurrent units were selected as the recurrent network. The well-known UCF-Crime dataset was used to form the training and test datasets. The classification results showed a high accuracy of 93%, which was higher than the accuracy of the classifiers considered in the review. Further research will focus on the practical implementation of the proposed hybrid neural network. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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13 pages, 5038 KiB

Open AccessArticle

Modeling of the Stress–Strain of the Suspensions of the Stators of High-Power Turbogenerators

by Oleksii Tretiak, Dmitriy Kritskiy, Igor Kobzar, Victoria Sokolova, Mariia Arefieva, Iryna Tretiak, Hromenko Denys and Viacheslav Nazarenko

Computation 2022, 10(11), 191; https://doi.org/10.3390/computation10110191 - 28 Oct 2022

Cited by 1 | Viewed by 1508

Abstract

In the submitted scientific work, the existing types of stator fastening design of turbogenerators and the main causes of the stressed state of the stator suspensions are considered. A detailed calculation of the complex stressed state of the turbogenerator stator suspension was carried [...] Read more.

In the submitted scientific work, the existing types of stator fastening design of turbogenerators and the main causes of the stressed state of the stator suspensions are considered. A detailed calculation of the complex stressed state of the turbogenerator stator suspension was carried out for a number of electrical sheet steels, taking into consideration the unevenness of the heat distribution along the horizontal axis of the unit. It is proposed that the calculation of the mechanical stress is carried out by means of the mechanical and thermal calculation, coordinated with the electrical one. The possibility of replacing steel 38Х2Н2ВА with steel 34CrNiMo6 and 40NiCrMo7 is indicated, subject to compliance with GOST 8479-70 for the same strength group. Full article

(This article belongs to the Special Issue Integrated Computer Technologies in Mechanical Engineering – Synergetic Engineering Ⅱ)

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