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  1. 7 Przegląd Elektrotechniczny
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  1. 2 Barnat W.
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  3. 2 Dmytriv Vasyl
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  1. 1 2024
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1
Content available Influence of Gear Eccentricity with Non-Parallel Axis on the Dynamic Behaviour of a Gear Unit Using a Gear Slice Model with 26 Degrees of Freedom
Jedliński Łukasz
Advances in Science and Technology. Research Journal
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2024
|
Vol. 18, no 2
88--102
EN
This study investigates the problems of eccentricity and backlash using an analytical spur gear model with 26 degrees of freedom (DOF). Previous studies have only investigated the case of eccentricity with a parallel shift of the axis of rotation of the gear relative to its geometric axis of symmetry. This study presents a novel method for determining the radius of eccentricity and its angular position at any distance from the bearing support, in which the axis of rotation and the geometric axis of symmetry of the gear are non-parallel. The effect of gear motion in the line of action (LOA) and off-line of action (OLOA) directions on backlash is precisely determined, despite the fact that most studies usually ignore gear displacement along the OLOA direction. Numerical simulations are performed to determine the effect of eccentricity on backlash, and their results confirm that the proposed method for determining the radius of eccentricity for any eccentricity type is correct. A gear slice model is used for dynamic analysis. Results show that the type of eccentricity has a significant effect on the gear dynamics and that eccentricity analyses have to include other cases than merely eccentricity with parallel axes of gears.
2
Content available SPAD timing jitter modeling using Fourier series
Eyvazi Kaveh, Karami Mohammad Azim
Optica Applicata
|
2023
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Vol. 53, nr 2
239--248
EN
In this paper, a simple analytical model for the Gaussian’s peak response part of the timing jitter of single photon avalanche diodes (SPADs) is proposed using Fourier series in the multiplication time calculation. The multiplication time characterizes avalanche multiplication process speed in which low multiplication time suggests a swifter response time and a higher avalanche speed. This paper presents an analytical solution which results in a more accurate multiplication time. The model is verified for SPADs implemented in 0.15 and 0.18 μm standard CMOS process, and the accuracy of the proposed analytical method in full-width at half-maximum (FWHM) calculation is improved by 25% and 5% with respect to the numerical model, respectively.
3
Content available remote Dyspersja hydrodynamiczna w procesie wypierania gazów w rdzeniach skalnych
Blicharski Jacek, Stopa Jerzy
Przemysł Chemiczny
|
2022
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T. 101, nr 1
50--54
PL
Przedstawiono wyniki badań laboratoryjnych wypierania azotu metanem w rdzeniach skalnych. Zaprezentowano model matematyczny eksperymentu oraz wyznaczono wartości współczynników dyfuzji molekularnej i dyspersji mechanicznej. Zaobserwowano zależność współczynnika dyspersji mechanicznej od ciśnienia w zakresie ciśnień 1-6 bar.
EN
Expts. of N2 displacement with MeH in rock cores were carried out on the laboratory test stand. The math. model of the expt. was presented and the coeff. of mol. diffusion and mech. dispersion were detd. The dependence of the mech. dispersion coeff. on the pressure in the range of 1-6 bar was obsd.
4
Content available remote The influence of the PCB design and the process of their manufacturing on the possibility of a defect-free production
Vasilyev Fedor, Isaev Vladimir, Korobkov Maksim
Przegląd Elektrotechniczny
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2021
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R. 97, nr 3
91--96
EN
The influence of the design parameters (width of the conductor, thickness of the copper foil and gap between the conductors) of the printed circuit board and the characteristics of the technological process of its production: stages of exposure and etching, on the output of defectfree products is considered. According to the results of the study, analytical dependences were obtained, which make it possible to determine the minimum width of the conductor depending on the thickness of the copper foil and etching factor. There is the model proposed that links the probability of manufacturing a defect-free printed circuit board with the parameters considered. The developed model can be extended with other design parameters and models of technological stages.
PL
W pracy dokonano oceny wpływu parametrów konstrukcyjnych płytki drukowanej (szerokości ścieżki, grubości folii miedzianej i szczeliny między ścieżkami) oraz charakterystyki procesu technologicznego jej wytwarzania: etapy naświetlania i trawienia, na wytwarzanie płytek PCB wolnych od wad. W ramach badań uzyskano zależności analityczne, które pozwalają określić minimalną szerokość ścieżki w zależności od grubości folii miedzianej oraz tzw. współczynnika trawienia. Zaproponowano model łączący prawdopodobieństwo wyprodukowania płytki drukowanej wolnej od defektów z rozważanymi w pracy parametrami. Opracowany model można rozszerzyć o inne parametry projektowe oraz modele etapów technologicznych podczas wytwarzania PCB.
5
Content available Modelling of work of the rotor-type blade pump with revolving stator
Dmytriv V. T., Lanets O. S., Dmytriv I. V., Horodetskyy I. M.
International Journal of Applied Mechanics and Engineering
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2021
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Vol. 26, no. 4
17--28
EN
In the article, the analytical dependences of modelling the cell cross-sectional area between two adjacent blades of a rotary blade pump and capacity for a pump with fixed and rotating stators are given, and analytical dependences are derived to model the power necessary to overcome the friction forces of the blades. The forces acting on the radially placed blade of a rotary pump with a fixed stator (non-rotating or stationary) and a rotating stator are analyzed. Design and technological parameters that influence the pump capacity and power are taken into account. The power required for the movement of the pump blade without taking into account the compression of the air has the opposite character of the change as to the pump capacity The capacity of a rotary pump with a rotating stator is three times higher than that of a stationary stator. The rotary pump with a rotating stator, with six radially spaced blades, consumes 0.854 [kW] less power to overcome the blade friction of 1313 kW The results of modelling of the pump work are given.
6
Content available Influence of the movement of involute profile gears along the off-line of action on the gear tooth position along the line of action direction
Jedliński Łukasz
Eksploatacja i Niezawodność
|
2021
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Vol. 23, no. 4
736--744
EN
When gears change their distance along the off-line of action (OLOA) direction, this affects the distance between the working surfaces of the meshing teeth along the line of action (LOA). This effect is usually neglected in studies. To include this effect precise equations are derived for spur gears. The analysis is carried out for the general case of spur gears with shifted profiles frequently used in the industry. The influence of OLOA gear displacement on LOA direction is also a function of gears parameters. An analysis is conducted, and the impact of parameters such as module, pressure angle, gear ratio, and the number of teeth is determined. As an example, a simulation of a 12 DOF analytical model is presented. The movement of gears along OLOA is caused by a frictional force that can be high during tooth degradation e.g. scuffing. Results show that when the movement of gears along the OLOA direction is significant, its influence on the distance between the mating teeth should not be neglected.
7
Content available Analytical Models for Optimal Design of a Trapezoidal Composite Channel Cross-Section
Pourbakhshian Somayyeh, Pouraminian Majid
Civil and Environmental Engineering Reports
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2021
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Vol. 31, no. 1
118--138
EN
In this paper, several analytical models are presented for the optimal design of a trapezoidal composite channel cross-section. The objective function is the cost function per unit length of the channel, which includes the excavation and lining costs. To define the system, design variables including channel depth, channel width, side slopes, freeboard, and roughness coefficients were used. The constraints include Manning’s equation, flow velocity, Froude number, and water surface width. The Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm was used to solve the optimization problem. The results are presented in three parts; in the first part, the optimal values of the design variables and the objective function are presented in different discharges. In the second part, the relationship between cost and design variables in different discharges is presented in the form of conceptual and analytical models and mathematical functions. Finally, in the third part, the changes in the design variables and cost function are presented as a graph based on the discharge variations. Results indicate that the cost increases with increasing water depth, left side slope, equivalent roughness coefficient, and freeboard.
8
Content available Analytical models tracing deformation of wood-framed walls during vertical transport
Malesza Jarosław, Miedziałowski Czesław
Archives of Civil Engineering
|
2021
|
Vol. 67, nr 1
131--146
EN
Vertical transport of wall-panels is a part of the prefabrication process of wood-framed buildings. The total dead weight of a wall is suspended on several lifting slings, pointwise clasping the top plate of the wall. This indicates, that all the weight of a wall is cumulated in sheathing-to-framing fasteners, usually staples. This article presents experimental investigations and analytical models evaluated for the description of light wood-framed walls in the process of lifting. Three different models cover the analytical approach: a model of a simple beam on elastic supports (BSS), a model of assembled beams (ACBS), three-dimensional (3D) spatial FE model of the wall (WFEM). Board-to-beam joint material parameters are determined on the base of experimental results. These connections are converted into two variants in the form of spring elements for 2D analysis, and beam elements for 3D analysis. The numerical results exhibit that the proposed models may correctly represent behavior of a real wall in lifting, applying elastic materials parameters.
PL
Transport pionowy tarcz ściennych jest częścią procesu prefabrykacji szkieletowych budynków drewnianych. Cały ciężar ściany spoczywa wówczas na kilku zawiesiach zaplecionych wokół górnej belki ściany. Oznacza to, iż obciążenie to kumuluje się w łącznikach (zszywkach) łączących górną belkę z poszyciem ściany. W artykule opisano badania doświadczalne oraz zaproponowano modele obliczeniowe ścian poddanych odkształceniom w procesie podnoszenia. W badaniach szczególną uwagę zwrócono na miejsca zaczepienia zawiesi i ich wpływ na pracę statyczną elementów konstrukcji. Dodatkowym efektem badań był wpływ wad materiałowych na zachowanie się konstrukcji. Badania eksperymentalne prowadzono do zniszczenia, które dla tarcz bez otworów i bez widocznych wad materiałowych obserwowano przy obciążeniu około P=50kN, natomiast w przypadku tarczy z wadami materiałowymi obciążenie niszczące osiągnęło wartość P=34kN. Dzięki badaniom uzyskano obraz deformacji górnego rygla oraz łączników poszycia i konstrukcji drewnianej w szczególności w obszarze bezpośrednich oddziaływań sił pochodzących od zawiesi. W artykule zaproponowano trzy modele obliczeniowe do oceny deformacji ścian: model belki na sprężystych podporach (BSS), model belek złożonych z połączeniami w postaci sprężyn (ACBS) i przestrzenny model MES (WFEM). W modelach belkowych połączenia opisano za pomocą elementów sprężynowych, a w modelu 3D za pomocą elementów belkowych. Parametry materiałowe użyte w opisie połączeń określono na podstawie badań złączy na zszywki. Analizy teoretyczne wykazała bardzo dobrą zbieżność modeli teoretycznych z badaniami doświadczalnymi w zakresie obciążeń P od około 8kN do 20kN. Ten zakres obciążeń określono na podstawie rzeczywistych obciążeń wynikających z ciężarów podnoszonych elementów, ponadto wielkości tych obciążeń wynikają z liniowo-sprężystej fazy pracy łącznika w połączeniu płyty poszycia z konstrukcją. Obciążenia powyżej P=20,00 kN wykazują w analizach modelowych większą sztywność niż to wynika z rezultatów badań doświadczalnych tarcz. Zaproponowany nowy, złożony model belkowy (ACBS) z dużą dokładnością odwzorowuje rzeczywistą pracę konstrukcji ścian na obciążenia ciężarem własnym w procesie podnoszenia. Może być zastosowany do ścian o różnej długości i konfiguracji otworów. Model ten w łatwy sposób może służyć ocenie wytężenia łączników, a w szczególności określeniu takiego rozstawu zawiesi, w którym zagwarantowane jest bezpieczne przenoszenie ściany. Jako kryterium bezpieczeństwa można, w zależności od wymagań, przyjąć: dopuszczalną nośność, dopuszczalną deformację lub dopuszczalną podatność łącznika.
9
Content available Modeling of Complex Non-Full-Availability Systems
Hanczewski Sławomir, Stasiak Maciej, Weissenberg Michał
Journal of Telecommunications and Information Technology
|
2020
|
nr 2
70--77
EN
This article presents an analytical model of complex non-full-availability telecommunications systems. The high degree of accuracy of the model is demonstrated by a comparison with the results of simulation experiments. Due to the introduction of an availability parameter, this model may be used in the future for analyzing real systems, such as, for example, cloud computing infrastructure. This will be possible provided that the function combining the physical structure of the system and the availability parameter is specified. This problem will be addressed in our future work and will constitute the next stage of research undertaken by the authors.
10
Content available Management of technological process optimisation
Lypchuk Vasyl, Dmytriv Vasyl
Engineering Management in Production and Services
|
2020
|
Vol. 12, no. 3
103--115
EN
The research aims to characterise the optimisation of a technological process depending on the main time parameters for production. The optimisation does not require to correct technical parameters of a system, but rather the organisational and managerial factors of the technological process. The workload is taken as an evaluation criterion, which factors in the probability distribution of time characteristics of computer process operations. Time characteristics that represent the performance of an operation influence the workloads of an operator and equipment, determining the productivity of the technological process. Analytical models were developed for the operational control of a production line efficiency considering the probability–statistical parameters pertaining to the performance of operations and technological equipment peculiarities. The article presents research results, which characterise the dependence of a production line efficiency on the type of equipment, and the duration of preparatory and final operations considering their probability. Under an optimal workload of the operator, the duration of the complete program changes linearly, regardless of the time required for the performance of operations by a computer without the involvement of the operator, and depending on the type of equipment. A managerial decision can be optimal under the condition that the factor of technological process efficiency (K_TP) tends to max. The developed method of analytical determination can be used to calculate the workload of both an operator and technological equipment. The calculations of the duration of a production line operation resulted in the methodology for the consideration of probability characteristics pertaining to the time distribution of the period required to perform operations, which influences the unequal efficiency of the production line. The probabilistic character of time distribution related to intervals of performed operations serves as a parameter in the management of technological process optimisation, which can be achieved using simulators of technological processes optimised in terms of their efficiency.
11
Content available An analytical model of a system with priorities servicing a mixture of different elastic traffic streams
Nowak B., Piechowiak M., Stasiak M., Zwierzykowski P.
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2020
|
Vol. 68, nr 2
263--270
EN
This article proposes an analytical model of a system with priorities servicing a mixture of different elastic traffic streams. The model presented in the article was developed as the extension of earlier works published by the authors. It utilizes the concept of equivalent bandwidth and then, following bandwidth discretization, uses the dependencies introduced on the basis of the assumptions adopted for the generalized Kaufman-Roberts formula and for the model of a full-availability group with traffic compression. The article presents a possibility of using the proposed model to model the radio interface in a multi-service mobile network and provides an example of the above with the interface of an LTE network. Since the proposed model is an approximate one, the results of the calculations are compared with the results of simulations. A comparison of the results confirms an acceptable level of accuracy of the model. The model can be successfully used in the analysis and design of links and nodes of telecommunication and computer networks.
12
Content available Assessment of the early-age strains and stresses in 2D restrained self-stressed members
Tur Viktar V., Sannikava Volha H.
Budownictwo i Architektura
|
2020
|
Vol. 19, no 4
85--94
EN
The paper presents the implementation of the modified strains development model (MSDM) for the two-way restrained self-stressed members such as expansive concrete-filled steel tubes and expansive concrete plane elements with arbitrary orthogonal reinforcement. The analytical approach allows defining the restrained strains and stresses in any 2D restraint conditions by following the iterative procedures and accounting for the elastic-plastic behaviour of expansive concrete at an early age. The consistency of the proposed method was confirmed by assessing the experimental results of the two series of the expansive concrete-filled steel tubes and three series of the expansive concrete plane members with mesh reinforcement in the centre of gravity.
13
Content available New expression to calculate quantity of recovered heat in the earth-pipe-air heat-exchanger operating in winter heating mode
Molcrette Vincent F. A., Autier Vincent R. B.
Archives of Thermodynamics
|
2020
|
Vol. 41, no 2
103--117
EN
A new expression is proposed to calculate the earth-energy of an earth-air-pipe heat exchanger during winter heating for three kinds of soil in France. An analytical model is obtained by using numerical computation developed in Scilab – a free open source software. The authors showed the comparison between their simple analytical model and experimental results. They showed the influence of different parameters to specify the size of the heat exchanger.
14
Content available An Investigation on Divorced Eutectoid Growth of Cementite in Eutectoid Steel
Biswas Prasenjit, Maity Joydeep
Archives of Metallurgy and Materials
|
2020
|
Vol. 65, iss. 3
1171--1176
EN
Divorced eutectoid growth of cementite in AISI 1080 steel is investigated as a function of cooling rate for incomplete austenitization-based heat treatment. Furthermore, a fundamental mathematical relationship is established through analytical treatment that correlates divorced eutectoid growth with effective cooling rate and degree of undercooling in view of bulk diffusion controlled growth model. As the cooling rate increases, the divorced eutectoid growth of cementite is gradually ceased. The result predicted by the analytical model closely matches with the experimental result (%Deviation ≤ 7).
15
Content available remote Model of Functioning of Information-Control System of Unmanned Car with Different Sensors Channels of Information Interaction
Klimenko Viktor, Sukhin Oleg, Kotov Denis, Lisovenko Denis
Systemy Logistyczne Wojsk
|
2019
|
Vol. 51, no. 2
85--92
EN
The article proposes an approach to the formalization of the process of information interaction of the information and control system of an unmanned vehicle with the environment, taking into account external destabilizing effects against the background of intra-system interference. The result of simulation modeling of the process of inverse processing of information arrays under conditions of a priori uncertainty is presented.
16
Content available remote BIM w budownictwie – parametryczne modele w prefabrykacji
Salamak Marek, Grzesiak Szymon
Materiały Budowlane
|
2019
|
nr 9
26--29
17
Content available remote Approximate estimation of stability of homogeneous beam on elastic foundation
Wstawska Iwona, Kędzia Piotr, Magnucki Krzysztof
Engineering Transactions
|
2019
|
Vol. 67, iss. 3
429--440
EN
The paper deals with a proposition of obtaining an analytical solution for a beam on elastic foundation. The main objective of presented work was stability analysis of the axially compressed beam. The analytical model was proposed. Shape function for inhomogeneous properties of the foundation was assumed. The Galerkin method was used to calculate the values of critical forces. Main conditions have been defined. The critical loads as a function of geometric and mechanical properties of the beam as well as inhomogeneous properties of the elastic foundation have been calculated.
18
Content available Analytical dynamic model of coefficient of friction of air pipeline under pressure
Dmytriv Vasyl, Dmytriv Ihor, Horodetskyy Ivan, Dmytriv Taras
Diagnostyka
|
2019
|
Vol. 20, No. 4
89--94
EN
To transport of the air in the pipeline, an analytical model is developed that takes into account the gas velocity, its kinematic and dynamic characteristics - density, viscosity depending on the pressure in a given space of the pipeline. The analytical model makes it possible to calculate the coefficient of friction of gas transportation in the pipeline at intervals of the absolute pressure from 220 to 2 kPa and M < 1 Mach numbers, depending on the diameter and length of the pipeline and physical and technological characteristics of the gas. The K1* aspect ratio is proposed, which characterizes in time the ratio of the dynamic force of movement of gas to the static pressure related to the diameter of the pipeline. The coefficient of air friction was modeled according to the vacuum pressure as a parameter of density and air flow. Air flow was taken from 1.917·10-3 m 3/s to 44.5·10-3 m 3/s respectively, diameters from 0.030 to 0.070 m and Mach number was M = 0.005-0.13. At the vacuum and excess pressures with increasing of Reynolds number and decreasing of Mach number the gas friction coefficient increased linearly. According to the simulation results as the pressure loss and the diameter of the pipeline are increased the friction coefficient increased as well. Analogically, at the vacuum metric pressure when the pressure loss and the diameter of the pipeline are increased the friction coefficient increased. At the pipeline internal diameters of 22, 30, 36 mm accordingly for pressure losses from 2 to 14 kPa the coefficient of air friction varies from 0.006 to 54.527 respectively.
19
Content available remote Developing a model and validating an instrument for measuring the adoption and utilisation of mobile government services adoption in Saudi Arabia
Alonazi Mohammed, Beloff Natalia, White Martin
Annals of Computer Science and Information Systems
|
2019
|
Vol. 18
633--637
EN
Many governments worldwide are taking advantage of the latest developments in mobile technology to take the digital delivery of government information and services (e-government) to their citizens a stage further. Accessing government information and services via a mobile device is known as m-government, a system designed to serve citizens, companies and government agencies alike. M-government also has unique advantages over e-government, not least enabling users to access government services at any time and from any location. This paper presents a pilot study of the MGAUM model that was developed to analyze factors influencing the adoption rate of m-government services in Saudi Arabia. With the aim of validating a survey instrument with which to conduct the main study in Saudi Arabia, a pilot survey instrument was developed and modified by using previous instruments from research into both e-government and m-government. This pilot questionnaire was distributed to 71 Saudi citizens in the UK, and the final sample was 58 valid responses. The results of this pilot study reveal that all items in the survey instrument were reliable and valid within the range of acceptable academic research and suitable for use in the main study. The results of this pilot study were analyzed using SPSS.
20
Content available Automation of analytical model construction for intellectual superstructure in next generation networks
Pustovyi B.
Zeszyty Naukowe Wydziału Elektroniki i Informatyki Politechniki Koszalińskiej
|
2018
|
Nr 12
49--60
EN
The software is suggested for automation of analytical model construction for intellectual superstructure in next generation networks. The software is designed for automation of the system probable states calculation, the construction of the Markov process transition graph and generation of equations system to determine stationary probabilities. An example of analytical model construction is represented for intellectual superstructure with centralized control principle.
PL
Zaproponowano oprogramowanie do zautomatyzowania analitycznego modelu budowy intelektualnej nadbudowy w sieciach następnej generacji. Oprogramowanie jest przeznaczone do automatyzacji obliczania stanów prawdopodobieństwa systemu, konstrukcji wykresu przejścia procesu Markowa i generowania układu równań w celu ustalenia stacjonarnych prawdopodobieństw. Przykład konstrukcji modelu analitycznego jest reprezentowany dla nadbudowy intelektualnej z zasadą scentralizowanej kontroli.
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