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  1. 5 PAK
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  1. 3 Gębura A.
  2. 2 Kiciński F.
  3. 2 Klupczyński K.
  4. 2 Kocman S.
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1
Content available Analysis of the influence of wave loads on offshore installations
Mustafayev Vahid T., Nasirov Chingiz R.
Nafta-Gaz
|
2024
|
R. 80, nr 2
91--95
PL
Given that the loads affecting offshore installations exhibit a broad range of variability in both temporal and spatial parameters, these loads are among the least studied components in the consideration of offshore installations as integrated systems. The existing calculation models and approaches used in design are rather conditional. When determining loads affecting offshore installations, the most common error is the description of loads in terms of time parameters, which lead to a distortion of the dynamic behavior of offshore installations. This is primarily because dynamic effects on the structure clearly demonstrate feedback between the influence of loads and the system itself. These loads can be classified as external and internal. Internal loads include loads from installation and construction processes, as well as loads from auxiliary and technological equipment, and external loads include ice, seismic, snow and wind loads. There are several approaches to solving problems related to the impact of wind waves on offshore installations. For this reason, an analysis and comparison of these methods were conducted to improve modeling process of offshore installations. Taking into account the impact of wave loads is a critical aspect of in developing the calculation model for the operational assessment of the residual resource of offshore installations.
EN
Biorąc pod uwagę, że obciążenia wpływające na instalacje morskie wykazują szeroki zakres zmienności, zarówno pod względem parametrów czasowych, jak i przestrzennych, obciążenia te są jednymi z najmniej zbadanych aspektów w rozważaniach nad instalacjami morskimi jako zintegrowanymi systemami. Istniejące modele obliczeniowe i koncepcje stosowane w projektowaniu są raczej uzależnione od warunków. Podczas określania obciążeń wpływających na instalacje morskie, najczęstszym błędem jest opis obciążeń w kategoriach parametrów czasowych, co prowadzi do zniekształcenia dynamicznego zachowania instalacji morskich. Dzieje się tak przede wszystkim dlatego, że dynamiczne oddziaływanie na konstrukcję wyraźnie wykazuje sprzężenie zwrotne między wpływem obciążeń a samym systemem. Obciążenia te można sklasyfikować jako zewnętrzne i wewnętrzne. Obciążenia wewnętrzne obejmują obciążenia związane z procesami instalacji i budowy, a także obciążenia związane z wyposażeniem pomocniczym i technologicznym, natomiast obciążenia zewnętrzne obejmują obciążenia spowodowane lodem, wstrząsami sejsmicznymi, śniegiem i wiatrem. Istnieje kilka koncepcji rozwiązywania problemów związanych z oddziaływaniem fal wiatrowych na instalacje morskie. Z tego powodu przeprowadzono analizę i porównanie tych metod w celu usprawnienia procesu modelowania instalacji morskich. Uwzględnienie wpływu obciążeń falowych jest krytycznym aspektem przy opracowywaniu modelu obliczeniowego do oceny operacyjnej pozostałych zasobów instalacji morskich.
2
Content available remote Zastosowanie cyfrowej analizy obrazu jako metody oceny postępu karbonatyzacji zapraw cementowych - wpływ dystorsji na wyniki badań próbek rzeczywistych oraz modelowych
Szydłowski Jakub
Cement Wapno Beton
|
2023
|
R. 28, nr 2
92--104
PL
Obecnie, ze względu na stosowanie aktywnych dodatków do cementu, badania postępu karbonatyzacji są kluczowe dla zapewnienia bezpieczeństwa konstrukcji. Proces pomiarowy zakłada użycie suwmiarki do wyznaczenia frontu karbonatyzacji. Tak wyznaczone wartości uśrednia się i na ich podstawie szacuje postęp korozji. Ze względu na to, że podejście normowe zakłada użycie metody nieciągłej wyznaczenia głębokości karbonatyzacji, pomiar może być obarczony błędem. Ponadto jego wykonanie, szczególnie dla wielu próbek, jest czasochłonne. Alternatywną metodą wyznaczania głębokości karbonatyzacji może być pomiar ciągły, z użyciem komputerowej analizy obrazu, który wyznacza rzeczywistą głębokość karbonatyzacji, ponieważ analizie poddawany jest cały obszar próbki. Komputerowa analiza obrazu jest zatem podejściem bardziej precyzyjnym i wygodnym. Nie jest ona natomiast podejściem ujętym w normach, jednak może stanowić pomoc w ocenie poprawności wyznaczenia głębokości karbonatyzacji. Głównym problemem proponowanej metody może okazać się błąd wynikający ze sferyczności obrazu, związany z dokładnością aparatu fotograficznego. Brak również prostopadłości układu optycznego aparatu względem próbki przy utrwalaniu jej obrazu, związanej z niewłaściwym ustawieniem aparatu fotograficznego. Problemem przy wykorzystaniu analizy komputerowej może okazać się również jakość uzyskanego obrazu W przeprowadzonych badaniach analizowano wpływ dystorsji obrazu na wyznaczenie powierzchni analizowanego obszaru, wykorzystując program ImageJ. Uzyskane wyniki pokazują, że komputerowa analiza obrazu jest dokładniejsza niż tradycyjna, a dystorsja spowodowana pochyleniem obrazu nie wpływa na uzyskiwane wartości w stopniu większym niż dokładność pomiaru tradycyjnego.
EN
Nowadays, because of the use of active additives in cement, studies on carbonation progress are crucial to ensure the safety of structures. Carbonation depth measurement involves the use of a calliper to determine the front of the carbonation. The values determined in this way are averaged, and the corrosion progress is estimated based on these values. Due to the fact that the standard approach assumes the use of a discrete method for determining the carbonation depth, the measurement may be subject to error, and its execution, especially for many samples, is time-consuming. An alternative method for determining the depth of carbonation may be continuous measurement, which determines the actual depth of carbonation since the entire sample area is analysed. Therefore, digital image analysis is the more precise and convenient approach. Unfortunately, it is not an approach, covered by the standards, but may help to assess the correctness of the determination, the carbonation depth. The problem with the use of digital analysis in proposed method may be the quality of the image obtained. The main problem may be the sphericity of the image, related to the nature of the camera, but also the lack of perpendicularity of the optical system of the camera to the sample when fixing its image, related to incorrect positioning by the camera operator. The results show that the digital image analysis is more accurate than the traditional approach, and that the distortion caused by the tilt of the image does not affect the obtained values to a greater degree than the measurement accuracy of the traditional approach.
3
Content available Impact of single-piece flow thermo-chemical treatment process conditions on hole quenching deformation
Stachurski Wojciech, Sawicki J., Zgórniak P., Wołowiec-Korecka E.
Archives of Materials Science and Engineering
|
2023
|
Vol. 121, nr 1
18--24
EN
Purpose: Pulsed low-pressure carburizing (LPC) and omnidirectional high-pressure gas quenching (HPGQ) are innovative methods for quenching the surface layer. The thermo-chemical treatment carried out by this method reduces quenching geometric deformations, with detailed numerical values not available in the literature due to the short existence of this method. Design/methodology/approach: Sixteen toothed elements of EN 20MnCr5 steel were subjected to pulsed low-pressure carburising with omnidirectional jet quenching in 4 groups, varying the process temperature (920°C, 960°C) and in two groups performing a tempering treatment. The elements were tested before machining by measuring their internal hole diameters, radial runout, roundness and cylindricity. These values were tested again after treatment. The direction of change and the statistical significance of the effect of treatment and its parameters, temperature and tempering were analysed. Findings: Thermo-chemical treatment significantly affects geometric changes in diameters, roundness, cylindricity and radial runout compared to elements without heat treatment due to physical transformations occurring during this treatment (p<0.05). Changing the process temperature in the value range of 920°C-960°C affects the hole diameter (makes it smaller) (p<0.05), but does not affect radial runout, cylindricity and roundness. The observed dimensional changes in diameters have numerically small values (<0.005 mm). The tempering treatment can affect the values of average diameters. Its effect on roundness, cylindricity and radial runout was not observed. Research limitations/implications: In the temperature range studied, the method of pulsed low-pressure carburising + omnidirectional high-pressure gas quenching makes it possible to raise the temperature of the process and shorten its duration without significant geometric changes in the treated elements. Practical implications: The method of pulsed low-pressure carburising and omnidirectional high-pressure gas quenching (HPGQ) ensures the maintenance of reproducible quenching deformations at a level significantly lower than conventional processing methods. Originality/value: The method of pulsed low-pressure carburising together with omnidirectional high-pressure gas quenching (HPGQ) is a method that has been used briefly in the industry, and there are few reports on it to date.
4
Content available Distortion Analysis of Thin-Walled Investment Castings
Mandal R., Roy Soumyajit, Sarkar Subhajit, Mandal T., Pramanick A. K., Majumdar G.
Archives of Foundry Engineering
|
2023
|
Vol. 23, iss. 3
59--60
EN
Dokra casting is famous for its Artistic value to the world but it is also sophisticated engineering. The technique is almost 4500 years old. It is practiced by the tribal artisans of India. It is a clay moulded wax-based thin-walled investment casting technique where liquid metal was poured into the red hot mould. Dimensional accuracy is always preferable for consumers of any product. Distortion is one of the barriers to achieving the accurate dimension for this type of casting especially for the bending parts. The cause and nature of the distortion for this type of casting must be analyzed to design a product with nominal tolerance and dimensional accuracy.
5
Content available Rekonstrukcja potrącenia pieszego, udokumentowanego na nagraniu wideo, przy wykorzystaniu programu Photorect 2.0
Winiarska Weronika, Kędziora Krzysztof
Paragraf na Drodze
|
2022
|
Nr 3
71--88
PL
Coraz częściej materiał dowodowy dotyczący wypadku drogowego zawiera filmy z kamer, które stanowią przydatny materiał w pracy biegłego. Analiza zapisanego na nich przebiegu zdarzenia jest najbardziej wiarygodną podstawą odtworzenia wypadku w tym prędkości i działań podejmowanych przez jego uczestników. Efektywne wykorzystanie nagrania wideo do analizy wypadku drogowego wymaga zwykle przeprowadzenia choćby jego wstępnej obróbki, np. wykadrowania i usunięcia niepotrzebnych fragmentów. W celu polepszenia jakości źródłowego materiału wideo w zakresie odwzorowania cech geometrycznych obiektów nagranych na filmie, potrzebne jest dokonanie korekty dystorsji, a następnie ortorektyfikacji. Często niezbędne jest także polepszenie obrazu, poprzez nakładanie na zapis wideo filtrów. Operacje te są możliwe do realizacji z użyciem programu PHOTORECT 2.0, co omówiono w artykule. Przekształcony film wideo, pozbawiony efektu perspektywy, odpowiednio wykadrowany oraz poddany ekstrakcji klatek użyto do przygotowania komputerowej symulacji zdarzenia, zsynchronizowanej z tym filmem.
EN
Increasingly, evidence of a road accident includes video recordings that provide useful material in the work of an expert w itness. The analysis of the recorded course of the event is the most reliable basis for accident reconstruction, including the speed and actions taken by the participants. An effective use of a video recording for a road accident analysis usually requires at least its initial processing, e.g. framing and removing unnecessary parts. In order to improve the quality of the source video material in terms of mapping the geometric features of the objects recorded on the film, it is necessary to correct the distortion, followed by orthorectification. It is also often necessary to improve the image by applying filters to the video recording. These operations are possible with the use of Photorect 2.0, which is discussed in the article. The transformed video, post-processed by means of perspective effect elimination, cropping and frame extraction was used for the preparation of a computer simulation of the event, synchronized with this film.
6
Content available remote Identyfikacja i modelowanie zniekształceń budynku zabytkowego na podstawie chmury punktów
Pawłowicz Joanna A.
Materiały Budowlane
|
2022
|
nr 11
60--62
PL
Obiekty zabytkowe są często skomplikowane, co utrudnia pomiar i identyfikację zniekształceń. Z pomocą przychodzi technologia skaningu laserowego 3D, która w szybki sposób pozwala na zebranie danych geometrycznych dotyczących budynku. Efektem jest uzyskanie chmury punktów, którą poddano analizie z wykorzystaniem oprogramowania Leica Cyclone, AutoCad i ReCap. To studium przypadku pokazuje, że skaning laserowy z powodzeniem może być wykorzystywany w identyfikowaniu zniekształceń występujących w budynkach.
EN
Historic objects are often complex, which makes it difficult to measure or identify distortions. The technology of 3D laser scanning comes to the rescue, which allows you to quickly collect geometric data about the building. Its effect is to obtain a point cloud, which was analyzed using Leica Cyclone, AutoCad and ReCap software. This case study shows that laser scanning can be successfully used to identify distortions in buildings.
7
Content available Proposed single-zone map projection system for Turkey
Yildirim Faruk, Kadi Fatih
Reports on Geodesy and Geoinformatics
|
2021
|
Vol. 112
35--45
EN
The coordinate base of the maps or sheets produced is the Universal Transversal Mercator (UTM) conformal projection, and it is not possible to work in a single coordinate system in Turkey. Therefore, a transition from UTM to other conformal projections is required. For the countries extending in an east–west UTM zone width like Turkey, composite projection (CP), a double standard paralleling Lambert Conformal Conic (LCC) and double map projections (DP) are used widely. However, this process causes increase in working load and processing errors by users. This study aims to determine a common projection system that can be used in the whole country. In this context, a composite projection from UTM and LCC projection has been defined for the first time. According to the results obtained, map projection CP with the least distortion values in both east–west and north–south directions has been chosen. With the CP selection, a single coordinate system has been determined for medium- and large-scale maps. Projection correction formulas, scale factor and false origin have been determined for map coordinates in CP. These distortions are obtained with a difference of less than 1 cm for 1 km long sides and less than 0.003″ for the azimuth value of this side, when the correction formulas are used.
8
Content available remote Analysis of material property models on WAAM distortion using nonlinear numerical computation and experimental verification with P-GMAW
Manurung Yupiter H. P., Prajadhiana Keval P., Adenan Mohd Shahriman, Awiszus Birgit, Graf Marcel, Haelsig Andre
Archives of Civil and Mechanical Engineering
|
2021
|
Vol. 21, no. 1
533--545
EN
This fundamental research deals with the investigation of material property model influences on distortion induced by multi-layered Wire Arc Additive Manufacturing (WAAM) with synergic-pulsed gas metal arc welding (P-GMAW) process which was modelled and simulated by means of non-linear numerical computation. The material property models of stainless steel SS316L component to be compared stem from three different sources namely existing database, initial wire and evolved component. The new property models were generated with advanced material modelling software JMATPRO based on chemical compositions analysed at initial wire and component using SEM–EDX. The flow curve for each material model was taken with the strain rates ranging from 0.001 to 1.0 s−1. In the numerical simulation, a coupled thermomechanical solution was adopted including phase-change phenomena defined in latent heat. Goldak’s double ellipsoid was applied as heat source model and simplified rectangular bead with hexagonal element type and meshing was developed to avoid extensive pre-processing effort and to reduce the computational time at post-processing level. Temperature behaviour due to the successive layer deposition was simulated considering heat transfer effect coupled to mechanical analysis. The adjustment of simulative transient to experimental thermal distribution lead to new fitted heat transfer coefficient. Prior to execution of numerical simulation, a sensitivity analysis was conducted to find the optimal number of elements or mesh size towards maximum reached temperature. It can be concluded based on the adjusted model, selected mesh size and experimental validation that numerical computation of substrate distortion with evolved material property of component and initial wire of SS316L yield closer average result within the relative error ranging between 11 and 16% compared to database material giving more than 22%.
9
Content available The influence of quenching temperature on distortions during the individual quenching method
Wołowiec-Korecka E., Stachurski W., Zgórniak P., Korecki M., Brewka A., Byczkowska P.
Archives of Materials Science and Engineering
|
2020
|
Vol. 105, nr 2
80--85
EN
Purpose: In this paper, the impact of hardening temperature on the quenching distortions which occur during low-pressure carburizing with gas quenching - using the individual quenching method - was analysed. Design/methodology/approach: The reference elements were subjected to carburizing at 980°C, followed by gas quenching at temperatures of 860°C, 920°C and 980°C. The geometrical measurements of the elements were made before and after the chemical treatment and the size of the quenching distortions of their geometrical parameters was determined. Findings: It was demonstrated that a high temperature of quenching has an unfavourable effect on changes in cylindricity and roundness parameters but, at the same time, reduces the size of distortion of outer parameters. Low temperature quenching reduces quenching distortions of cylindricity and roundness parameters while increasing the distortion of outer dimensions. Research limitations/implications: Based on the research and analysis carried out in this work, it was found that the use of lower quenching temperature is justified in economic and quality terms. Practical implications: In the case of the aviation or automotive industry, very high quality of manufactured elements along with a simultaneous reduction of their production costs is extremely important. Maintaining the dimensions of the elements during heat treatment is extremely difficult. The tests allowed to determine the optimal hardening temperature, which brings with it acceptable deformations. Since it is easier to “repair” the outer geometrical dimensions (diameter, thickness), it seems that quenching from lower temperatures is a more favourable process. Originality/value: The conducted tests allowed to determine the most favourable conditions for hardening elements from the automotive industry, taking into account the occurring deformations and their subsequent processing
10
Content available remote Finite beam element with 22 DOF for curved composite box girders considering torsion, distortion, and biaxial slip
Zhu Li, Wang Jia-Ji, Li Ming-Jie, Chen Chao, Wang Guang-Ming
Archives of Civil and Mechanical Engineering
|
2020
|
Vol. 20, no. 4
16--34
EN
Experimental and numerical study on the mechanical performance of curved steel–concrete composite box girders is reported in this research. First, this research establishes a theoretical model for curved composite girders with 11° of freedoms (DOFs) for each node. The DOFs include the longitudinal displacement, transverse displacement, deflection, torsion angle, warping angle, and interface biaxial slip between steel and concrete. Based on the virtual work theorem, the equilibrium function, the stiffness matrix, the node displacement matrix and the external load matrix are proposed for the curved composite girders using the FE spatial discretization. Second, the authors conduct an experimental program on three large-scale curved composite girders with various interface shear connectors and central angles. The comparison between the developed finite beam element, the elaborate FE model and the test results indicates the developed finite beam element has an adequate level of accuracy in predicting the deflection, the torsion angle and the axial strain distribution of test specimens. Third, based on the developed finite beam element model, the effect of initial curvature, number of diaphragms, and the interface connector stiffness on the curved composite girder is examined. The simulation results showed that the initial curvature significantly contributes to the displacement and stress of composite girders. Applying more diaphragms can notably reduce the distortion angle and distortion displacement. The interface shear connector stiffness has a significant influence on the curved composite girder. With the increasing shear connector stiffness, the displacement and stress of curved composite girders decrease notably. Based on the parametric analyses, it is recommended to limit the central angle of simply supported composite girder below 45°, to apply an adequate number of diaphragms, and to design curved composite girders as fully shear connection specimens.
11
Content available remote Switching overvoltage analyses under distorted supply voltage conditions
Chmielewski Tomasz, Oramus Piotr, Kuczek Tomasz
Przegląd Elektrotechniczny
|
2019
|
R. 95, nr 3
119--125
EN
This paper presents the impact of the higher harmonics presence in the supply voltage on the generated transient recovery voltage (TRV), which inherently appear between circuit breaker contacts (CB) after current interruption. In the current version the international standards from committees such as CIGRE or IEC are silent about this topic. The research presented in this paper, includes laboratory experiments and simulations, for ideal supply voltage conditions and the supply voltage with certain harmonic content. The black-box conductance model of electric arc, based on Cassie-Mayr equation was used for the simulations.
PL
Artykuł przedstawia analizę wpływu wyższych harmonicznych w napięciu zasilającym na napięcie powrotne (TRV) pojawiające się między stykami wyłącznika po przerwaniu prądu. Motywacją do powstania artykułu stał się fakt, iż normy międzynawowych komitetów takich jak CIGRE czy IEC w obecnych wersjach nie poruszają tego zagadnienia. Artykuł zawiera wyniki analiz oraz eksperymentów laboratoryjnych dla warunków bez harmonicznych oraz z harmonicznymi obecnymi w napięciu zasilającym. W symulacjach zastosowano model łuku elektrycznego w oparciu o równania Cassiego – Mayra.
12
Content available The influence of hardening medium in the vacuum carburizing process on the distortion of machine elements used in the automotive industry
Pawęta S., Pietrasik R.
Journal of Achievements in Materials and Manufacturing Engineering
|
2019
|
Vol. 94, nr 1-2
32--40
EN
Purpose: As part of this study, the influence of the hardening medium on distortions of FineCarb® carburized rollers used in the automotive industry as elements of fuel pumps has been examined. The analysis was carried out for the process of quenching in gas at different pressure of cooling gas and quenching in oil at variable delay time of oil mixers. Design/methodology/approach: The research was carried out on real elements used in the automotive industry as elements of fuel pumps. FineCarb® vacuum carburizing technology was used in order to obtain optimal parameters of the surface layers. During quenching a variable related to the parameters of the quenching medium was introduced. For quenching in gas it was the pressure at which nitrogen was introduced into the cooling chamber, while for quenching in oil it was the time of mixers delay. The sample batch was laid out in accordance with the PPAP (Production Part Approval Process) requirements for the automotive industry. Microhardness and radial runout measurements were carried out on the samples and subjected to statistical analysis. Findings: The analysis of each hardening processes has showed that depending on the cooling medium used, different distortion values are obtained. The distortion value is significantly influenced by the parameters of the hardening process - gas pressure/oil mixers delay. With the proposed quenching parameters, there is no relationship between the location of the sample in the furnace chamber and the distortion value. The smallest hardening distortions were obtained as a result of the hardening process in gas at a gas pressure of 3 bar. Hardening in gas was characterized by the smallest scatter values of obtained results of radial runout. Research limitations/implications: Basing on the studies and analyses carried out in this work, it can be concluded that the introduction of gas quenching technology instead of oil quenching technology is justified qualitatively and economically alike. Hardening in gas was also characterized by the smallest scatter values of obtained results of radial runout. This is an extremely important technological and economic aspect, due to the cost of grinding processing. Practical implications: The automotive and aviation industries are putting ever greater demands on the quality of manufactured components while reducing costs. It requires optimization of technological processes from co-operators. In the case of hardening plants, the most important aspect is obtaining repeatable, precisely planned parameters of the carburized layer, as well as minimizing the negative phenomena that cause dimensional changes after hardening of elements. The tests allowed to determine the most effective hardening conditions in terms of obtained distortions and costs of eliminating distortions. However, the selection of the optimal parameters depends on whether the core hardness requirements are also determined. Originality/value: The conducted tests allowed to determine the most effective hardening conditions in terms of obtained distortions, costs of levelling distortions and a complete technological process for the automotive industry.
13
Wpływ metody spawania na odkształcenia geometryczne wyrobu o kształcie obrotowo-symetrycznym
Piechowski M., Klupczyński K., Kiciński F.
Przegląd Mechaniczny
|
2018
|
nr 4
30--34
PL
W artykule zawarto porównanie odkształceń w wyrobie o kształcie obrotowo- symetrycznym powstałych podczas spawania alternatywnymi metodami (TIG oraz laserową). Badaniu poddano profil zewnętrzny wyrobu zarówno przed, jak i po obróbce wykańczającej. Badania wykazały znaczne różnice odkształceń w zależności od zastosowanej metody. Za przyczynę większego odkształcenia z zastosowaniem klasycznej metody spawania łukowego (TIG) można uznać wielokrotnie większą ilość ciepła wprowadzonego w obszar złącza, co potwierdzają przeprowadzone obliczenia. W trakcie obydwu prób spawania dokonano rejestracji parametrów, co pozwoliło na wyznaczenie ilości wprowadzonego ciepła. Porównanie ukazuje także ekonomiczne korzyści zastosowania metody spawania laserowego jako substytutu metody TIG.
EN
The article compares two welding methods - TIG (tungsten inert gas) and laser welding. The welding process was carried out in a product with rotationally symmetrical shape. The external profile of the product was tested before and after the finishing turning. The research has found significant differences in distortion depending on the used welding method. It is assumed that the bigger distortion factor during classic arc welding was caused by the higher heat input inside the welding area. (As a cause of bigger distortion factor during classic arc welding method, we can assume higher heat input inside the welding area.) During both welding tests, the welding parameters were checked and registered. This operation allowed to indicate the real heat input for two different welding methods. The comparison has also shown the economic benefits of using laser welding method instead of TIG welding.
14
Porównanie wydajności oraz jakości spawania zmechanizowanego i zautomatyzowanego metodą TIG wspornika ze stali AISI 304
Piechowski M., Klupczyński K., Kiciński F.
Przegląd Mechaniczny
|
2018
|
nr 6
17--22
PL
W artykule zawarto porównanie produkcji elementu typu wspornik przy wykorzystaniu metod spawania zmechanizowanego oraz zautomatyzowanego. Badaniu poddano odkształcenia w wyrobie wynikające z sekwencji operacji spawalniczych oraz wydajność procesu. Porównano czasy wykonania dla obu metod produkcyjnych, a także wykazano różnice czasu przy wykonaniu partii logistycznej wyrobu. Pomiary oraz wyliczenia wykazują przewagę metody zautomatyzowanej ze względu na możliwość wykonania czynności jednocześnie (metoda zautomatyzowana w przeciwieństwie do zmechanizowanej nie wymaga angażowania operatora w pełnym wymiarze jego dostępnego czasu). Ze względu na równoległe wykonanie spoin leżących naprzeciw siebie, w metodzie zautomatyzowanej uzyskano znacznie niższe odkształcenia.
EN
The article compares the mechanized and automated welding methods used for the manufacturing of a hanger type product. The research focused on the product distortion caused by welding sequence as well as on the process efficiency. The cycle times were compared for both production methods, and the differences in the completion times were found when manufacturing the entire batch size. Both measurements and calculations demonstrated the advantage of the automated method which allowed simultaneous operations. Unlike the mechanized method, the automated method did not require the full time availability of the operator. Moreover, due to the fact that the opposite welds could be done in parallel, the automated method proved to cause less distortion.
15
Content available remote Wpływ odkształcenia napięcia na przepięcia ziemnozwarciowe
Łowczowski K.
Przegląd Elektrotechniczny
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2018
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R. 94, nr 10
41--44
PL
W artykule przedstawiono sposób modelowania odkształceń napięcia na szynach GPZ oraz sposób modelowania zwarć doziemnych. Zbadano wpływ odkształcenia napięcia na wartość szczytową oraz wartość ustaloną przepięć.
EN
The paper presents modeling of voltage distortions on 110/15 kV busbar and modeling of an earth faults. Impact of voltage distortions on transient peak voltage and voltage in stable overvoltage is investigated.
16
Content available A method for measuring the quality parameters of image intensifier based on projecting phase-shifting gratings
Sun S., Cao Y., Chen C., Fu G., Wang Y., Xu X.
Optica Applicata
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2018
|
Vol. 48, nr 1
39--51
EN
A method for measuring the quality parameters of image intensifier based on projecting phase-shifting gratings is proposed. A set of designed phase-shifting gratings are projected into the measuring system orderly to obtain the magnification parameter of the measured image intensifier, and the phase caused by the measured image intensifier. After obtaining the referential phase caused by only the magnification of the measured image intensifier, the phase caused by the distortion of the measured image intensifier is extracted by phase calculating and phase unwrapping. Both the global distortion and the partial distortion of the measured image intensifier can be measured by phase-to-distortion matching at the same time. The experimental results show that the proposed method can measure the multiple quality parameters of image intensifier effectively.
17
Content available Cryptosystems using subgroup distortion
Chatterji I., Kahrobaei D., Lu N. Y.
Theoretical and Applied Informatics
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2017
|
Vol. 29, No. 1-2
14--24
EN
In this paper we propose cryptosystems based on subgroup distortion in hyperbolic groups. We also include concrete examples of hyperbolic groups as possible platforms.
18
Content available remote Metody analiz numerycznych procesów spawania złożonych konstrukcji
Kik T., Slováček M.
Przegląd Spawalnictwa
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2017
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R. 89, nr 5
41--45
PL
W artykule przedstawione zostały metody obliczeniowe stosowane w analizach numerycznych procesów spawania konstrukcji złożonych z wielu elementów i złączy spawanych. Opisane zostały metody obliczeniowe stosowane w nowoczesnym oprogramowaniu wykorzystującym metodę elementów skończonych i stosowane z powodzeniem od dłuższego czasu w przemysłowych aplikacjach programu SYSWELD. Przedstawiony został również przykład prowadzenia analiz techniką shrinkage jako nowoczesnego podejścia do zagadnień obliczeniowych złożonych konstrukcji spawanych, pozwalającego na sprawną i szybką optymalizację procesu spawania w celu minimalizacji odkształceń konstrukcji.
EN
The article presents calculation methods used in numerical analyses of welded structures made from many elements and joints. Presented simulation methods used in modern FEM software are successfully used from longer time for industrial application of SYSWELD. This article described also an example of shrinkage method calculations as modern approach to the calculation problem of complex welded constructions which allows to smooth and fast optimize the welding process to achieve the distortion minimalization.
19
Content available Study of Distortion on the Example of the Rings from Ductile Iron and Cast Steel
Łukasik K., Nawrocki P., Misiak J., Myszka D.
Archives of Foundry Engineering
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2017
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Vol. 17, iss. 4
97--102
EN
The paper attempts to analyze distortions of cast iron and cast steel rings, after heat treatment cycles. The factors influencing distortion are: chemical composition of material, sample geometry, manufacturing process, hardenability, temperature and heat treatment method. Standard distortion tests are performed on C-ring samples. We selected a ring-model, which approximate the actual part, so that findings apply to gear rings. Because distortion depends on so many variables, this study followed strictly defined procedures. The research was started by specifying the appropriate geometry of the samples. Then, the heat treatment was conducted and samples were measured again. The obtained results allow to determine the value of the resulting distortion and their admissibility. The research will be used to evaluate the possibility of using the material to produce parts of equipment operated under extreme load conditions.
20
Content available Distortion of 16MnCr5 steel parts during low-pressure carburizing
Dybowski K., Niewiedzielski R.
Advances in Science and Technology. Research Journal
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2017
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Vol. 11, no 1
201--207
EN
One of the many advantages of low pressure carburizing (LPC) is that it can be combined with high-pressure gas quenching. This makes it possible to achieve workpieces with pure metallic surfaces, less distortion hardening, and, above all, it allows a more reliable and repeatable treatment than conventional oil quenching. This article presents a study of the distortion rate of workpieces carburized at low pressure then quenched in nitrogen at 1.4 MPa. By comparing the distortion which takes place during the carburizing stage only and the carburizing combined with post-carburizing heat treatment it will be possible to assess the distortion rate and its causes at the different stages of the heat treatment process.
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