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1
Content available remote Experimental analysis of single point incremental forming of truncated cones in DC04 steel sheet
Krasowski B., Kubit A., Trzepieciński T., Slota J.
Advances in Materials Science
|
2020
|
Vol. 20, nr 4(66)
5--15
EN
Experimental tests to form truncated cones were carried out on a 3-axis milling machine. 0.8-mm thick low-alloy DC04 steel sheets were used as test material. The profile tool-path trajectory was generated using the EDGECAM software. The slope angle and diameter of the base of the conical shaped drawpieces were 70°-72° and 65 mm, respectively. The drawpiece heights were up to 75 mm. The full synthetic lubricant 75W85 was used to reduce the frictional resistance. The effect of selected incremental forming parameters on the formability of the DC04 sheet and the susceptibility to crack formation have been analysed and discussed. It was found that the surface roughness of the workpiece is strongly influenced by step depth. By controlling the feed rate, it is possible to prevent failure of the material.
2
Content available Influence of friction condition on failure location of AA5754 aluminium sheet in Nakajima test
Slota J., Šiser M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2018
|
z. 90 [298], nr 1
57--66
EN
This paper presents the results of numerical and experimental investigations on the influence of friction on failure location in Nakajima formability tests. Finite element (FE) simulations were performed using commercial explicit dynamic FE code. The numerical results obtained from the FE simulation were compared with experimental data from Nakajima tests. A 3D digital image correlation system ARAMIS was used in experiments. The location of failure on the sample was detected depending on friction conditions. The studies confirmed that the crack location near the centre of the specimen as required by the ISO standard could be obtained for low values of the friction coefficient. The numerical simulation combined with the inverse analysis was used to estimate a real value of the friction coefficient in the Nakajima formability test.
PL
W pracy przedstawiono numeryczne i eksperymentalne badania wpływu tarcia na lokalizację uszkodzeń w teście Nakajima. Symulację numeryczną testu przeprowadzono przy użyciu komercyjnego jawnego dynamicznego kodu FE. Wyniki uzyskane z symulacji FE porównano z danymi doświadczalnymi. W badaniach eksperymentalnych wykorzystano system ARAMIS do optycznej korelacji obrazu 3D. Lokalizacja uszkodzenia próbki wykazała zależność od warunków tarcia. Badania potwierdziły, że położenie pęknięcia w pobliżu środka próbki, zgodnie z wymaganiami normy ISO, można uzyskać dla niskich wartości współczynnika tarcia. Do oszacowania rzeczywistej wartości współczynnika tarcia w teście odkształcalności według Nakajima zastosowano symulację numeryczną połączoną z analizą odwrotną.
3
Content available Springback prediction of stretching process using finite element analysis for dp600 steel sheet
Slota J., Gajdos I., Spišák E., Šiser M.
Acta Mechanica et Automatica
|
2017
|
Vol. 11, no. 1
5--8
EN
Springback phenomenon is well predicted for some mild steel materials, but not for steels with higher strength. One of the most used tools to stamping optimization is usage of finite element analysis. In order to accurate describe the real behaviour of the materials for stamping of vehicle panels, the application of proper hardening rule seems to be crucial. Due to higher accuracy of predicted results, high strength steel sheets are usually modelled by means of kinematic or mixed isotropic-kinematic hardening models. In this paper the springback prediction of advanced high strength steel DP600 by numerical simulation was investigated. Through cyclic tension-compression tests, the material characterization has been performed for DP600 steel sheet. Different hardening models (isotropic, kinematic and mixed isotropic-kinematic) used in the simulations were compared with expreriment. The Yoshida–Uemori model succesfully describe the kinematic behaviour of the material and provided more accurate results than others.
4
Content available Interpretation of warpage simulation results in AMSI
Gajdoš I., Jachowicz T., Slota J., Krasynskyi V
Applied Computer Science
|
2015
|
Vol. 11, no 2
5--16
EN
The article describes the problematic of interpretation of warpage simulation results in Autodesk Simulation Moldflow Insight. Warpage results are relatively easy to obtain from injection molding analysis, but the result interpretation demands higher skilled user. For detailed warpage evaluation based on specific dimensions is application of anchor plane necessary. Theory of anchor plane creation is described and anchor planes were applied for inspection of critical dimension on molding “terminal box”.
5
Content available FEM Simulation of Deep Drawing Process of Aluminium Alloys
Slota J., Gajdos I., Jachowicz T., Siser M, Krasinskyi V.
Applied Computer Science
|
2015
|
Vol. 11, no 4
7--19
EN
This paper presents results of research with FEM simulation of sheet metal forming process. The two types of aluminium alloys from 5XXX and 6XXX series, which are used in automotive industry, were compared. The computer simulation and numerical analysis of deep drawing cup test were used to predict the ability of the forming of these alloys. The plasticity model Hill'90 was used for stamping simulations. The results of numerical simulation were validated by real experiment using sheet metal testing machine Erichsen 145-60. Both results were compared with regard to prediction accuracy in changes of thickness and ear profile.
6
Content available remote Numerical simulation of deep-drawing process
Majerníková J., Spišák E., Slota J., Frącz W.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2014
|
z. 86 [290], nr 4
561--568
EN
The article deals with the analysis of formability of deep-drawing DC06 steel sheets. The aim of the investigations is to verify possibilities of formability of sheet metal with thickness of 0.85 mm. The mechanical parameters of the sheets have been determined in uniaxial tensile and bulge tests. The numerical simulations using AUTOFORM has been carried out for two drawpiece models. Obtained results can be used during the simulation of real forming process.
PL
Artykuł obejmuje tematykę analizy odkształcalności blachy stalowej głęboko tłocznej gatunku DC06. Celem badań była weryfikacja możliwości odkształcania blach o grubości 0,85 mm. Właściwości mechaniczne blach określono w testach jednoosiowego rozciągania oraz wybrzuszania blachy. Symulacje numeryczne w programie AUTOFORM przeprowadzono dla dwóch modeli wytłoczek. Otrzymane wyniki mogą być wykorzystane do symulacji rzeczywistego procesu formowania.
7
Content available remote Infuence of path generation strategy on tensile properties of FDM prototypes
Gajdoš I., Spišák E., Slota J., Kaščák L.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2013
|
z. 85[288], nr 2
139--148
EN
This paper presents the results of a study evaluating the influence of path generation strategy of Fused Deposition Modeling (FDM) prototypes on mechanical properties of material. Several scientific studies were researching the problematic of path generation and internal structure of FDM prototypes. Mostly the influence on mechanical properties was observed. The presented study focuses on assessment of mechanical property of part fabricated using fused deposition modeling (FDM) technology in uniaxial tensile test. In this study standardized uniaxial tensile test (STN ISO 527-2) was used to determine tensile properties of specimens from ULTEM 9085. As the relation between mechanical property and process parameters is difficult to establish, attempt has been made to derive the empirical model between the processing parameters and mechanical properties using statistical methods. One of the parameter in path generation was the positive air-gap between fibres in internal raster. In actual practice, the parts are subjected to various types of loadings. Result show that proper model orientation when the orientation of load is known, can help to reduce the build time and material consumption.
PL
W pracy przedstawiono wyniki badań oceniających wpływ strategii generowania ścieżki prototypów wytwarzanych metodą osadzania topionego materiału (OTM) na właściwości mechaniczne materiału. Liczne badania naukowe podejmowały problematykę generowania ścieżki oraz wewnętrznej struktury prototypów OTM. W większości przypadków zaobserwowano wpływ sposobu wytwarzania prototypów na ich właściwości mechaniczne. Prezentowane badania skupiają się na ocenie właściwości mechanicznych w teście rozciągania części wytwarzanych technologią osadzania topionego materiału. W badaniach wykorzystano znormalizowaną próbę jednoosiowego rozciągania (STN ISO 527-2) do określenia właściwości przy rozciąganiu próbek z materiału Ultem 9085. Relacja pomiędzy właściwościami mechanicznymi i parametrami procesu jest trudna do ustalenia, dlatego skupiono się na określeniu modelu empirycznego pomiędzy parametrami procesu i właściwościami mechanicznymi, wykorzystując metody statystyczne. Jednym z parametrów generowania ścieżki była dodatnia szczelina pomiędzy włóknami wewnętrznego rastra. W praktyce części prototypowe są poddawane różnego typu obciążeniom. Wyniki badań wykazały, że poprawna orientacja części pozwala na skrócenie czasu budowy modelu oraz zmniejszenie ilości potrzebnego materiału.
8
Content available remote Experimental and numerical analysis of springback prediction in U-bendings of anisotropic sheet metals
Slota J., Jurčišin M., Dvořák M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2013
|
z. 85[288], nr 4
525--533
EN
Springback is one of the most important problems that should be taken into consi-deration during design of sheet metal forming process with the increasing application of advanced high strength steels and light-weight alloys. The degree of springback experienced with the latest generation materials is so high, and the materials so strong, that it is not possible to eliminate the springback in the prototyping. It becomes mandatory to compensate for springback as part of the draw die design, which is usually carried out through numerical simulation. The springback behavior of three categories of sheet steels (TRIP, HSLA and mild steel) with thicknesses ranging from 0.75 to 0.85 mm was investigated by means of the cyclic U-bending test. This phenomenon can be defined as an elastically-driven change of shape of the deformed part upon removal of external loads. Steel sheets were bent on the two different die radii and after first cycle were bent reverse. The influence of die radius on amount of springback of the steels was considered. Value of the springback angle change after the first and second cycle was measured. The change of values of angles between cycles is caused by the Bauschinger effect. This process was investigated experimentally and numerically. Numerical investigation was performed in static implicit finite element code Autoform.
PL
Sprężynowanie jest jednym z głównych problemów, które powinny być uwzględniane podczas projektowania procesów kształtowania coraz częściej stosowanych blach stalowych wysokowytrzymałych i wytwarzanych ze stopów lekkich. Stopień sprężynowania obserwowany podczas badań eksperymentalnych niedawno opracowanych gatunków materiałów jest tak wysoki, przy jednoczesnej dużej wytrzymałości tych materiałów, że nie jest możliwe wyeliminowanie sprężynowania na etapie prototypowania. Kompensacja sprężynowania jest więc obowiązkowa i jest częścią procesu projektowania narzędzia, co jest zwykle przeprowadzane za pomocą symulacji numerycznej. Badano sprężynowanie trzech gatunków blach (TRIP, HSLA i stal miękka) o grubościach od 0,75 do 0,85 mm za pomocą testu U-gięcia. Sprężynowanie może być zdefiniowane jako sprężysta zmiana kształtu odkształconej części po usunięciu obciążenia zewnętrznego. Blachy stalowe gięto za pomocą matryc o dwóch różnych promieniach. Po zakończeniu pierwszego cyklu gięcia blachy były gięte w kierunku przeciwnym. Analizowano wpływ promienia matrycy na wartość sprężynowania. Wartość kąta sprężynowania mierzono po pierwszym i drugim cyklu gięcia. Zmiana wartości kątów pomiędzy tymi cyklami jest określana jako efekt Bauschingera. Proces gięcia badano eksperymentalnie i numerycznie za pomocą programu do obliczeń metodą elementów skończonych Autoform z procedurą static implicit.
9
Content available The sensitivity of a photogrammetric method in formability analysis
Slota J., Jurčišin M., Gajdoš I., Spišák E.
Acta Mechanica et Automatica
|
2013
|
Vol. 7, no. 2
117--123
EN
Nowadays is a possible to implement numerical simulation and photogrammetric inspection to the complex process chain of in-spection. In the recent years there has been significant progress in accuracy improving of these methods of inspection in pre-production or post-production stage of manufacturing. This article discusses these two methods from sensitivity and comparison point of view. Most attention has been paid to the photogrammetric method and his sensitivity to using different approaches. Results were compared with the result of numerical simulation and experiment. Numerical simulation was performed in static implicit finite element code Autoform. For this purpose, GPS cover of galvanized steel of DQ category was used for inspection. In this paper was proved that photogrammetric method of strain measurement is highly sensitive on the various external factors. Further results and findings are included in the next chapters of this paper.
10
Content available remote Experimental and numerical prediction of springback in V-bending of anisotropic sheet metals for automotive industry
Slota J., Jurčišin M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2012
|
z. 84[284], nr 3
55--68
EN
Springback is a common phenomenon in sheet metal forming, caused by the elastic redistribution of stresses during unloading. It has been recognized that springback is essential for the design of tools used in sheet metal forming operations. A finite element method (FEM) code has been used to analyze the sheet metals V-bending process. In the work, three types of steels TRIP, AHSS and mild steel were used. Normal anisotropic material behavior has been considered. A contact algorithm for arbitrarily shaped rigid tools has been realized by means of accurate approach. This paper describes a robust method of predicting springback under bending and unbending of sheets. Constitutive models, aimed at predicting the final shape of the sheet after the springback by varying the setting of the operational parameters of the forming process, were discussed. The accuracy of the model was verified by comparison with results of PAM-STAMP 2G package and experimental results.
PL
Sprężynowanie jest powszechnym zjawiskiem występującym podczas kształtowania blach spowodowanym zmianą rozkładu naprężeń po zdjęciu obciążenia. Zauważono, że znajomość sprężynowania jest istotna w projektowaniu narzędzi używanych podczas operacji kształtowania blach. Program oparty na metodzie elementów skończonych (MES) został wykorzystany do analizy procesu wyginania. W badaniach wykorzystano blachy stalowe TRIP, AHSS i blachy ze stali miękkiej. Uwzględniono anizotropię normalną materiałów blach. Algorytm kontaktu dla sztywnych narzędzi o dowolnym kształcie został zrealizowany za pomocą podejścia ścisłego. W artykule opisano metodę przewidywania sprężynowania podczas gięcia i odciążania blach. Omówiono modele konstytutywne ukierunkowane na przewidywanie końcowego kształtu blachy po sprężynowaniu, przy zróżnicowanych parametrach procesu kształtowania. Dokładność modelu została zweryfikowana przez porównanie wyników obliczeń w programie PAM-STAMP 2G z wynikami eksperymentalnymi.
11
Content available remote Experimental and numerical analysis of the deep drawing process using optical measuring system
Slota J., Jurčišin M.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2012
|
z. 84[284], nr 4
37--45
EN
In this paper optimization of the deep drawing process with using a modern photogrammetric measurement system is discussed. The results obtained from optical measuring are compared with the results of a numerical simulation. The numerical simulation of this process was performed using two commercial FEM codes, which use different time integration schemes. Various results are illustrated in the details, compared and discussed. Optimization of the deep drawing process can reduce the amount of product defects, production cost and can improve the quality of products.
PL
Wyniki otrzymane z zastosowaniem optycznego systemu pomiarowego zostały porównane z wynikami symulacji numerycznych. W artykule przedstawiono optymalizację procesu głębokiego tłoczenia z wykorzystaniem nowoczesnego fotogrametrycznego systemu pomiarowego. Symulacja numeryczna tego procesu została wykonana za pomocą dwóch komercyjnych programów MES z użyciem różnych schematów całkowania czasu. Różne wyniki zostały szczegółowo zilustrowane, porównane i omówione. Optymalizacja procesu głębokiego tłoczenia może zmniejszyć liczbę wad wyrobu i koszt produkcji oraz poprawić jakość wyrobów.
12
Content available remote The latest actual trends in process of design and production in automotive industry
Fabian M., Spisak E., Seminsky J., Slota J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2010
|
z. 80 [274]
73-80
EN
Time of innovation cycle in automotive industry is being reduced thanks to increasing market competition. It is possible to follow this trend first of all by means of CA-applications in the design and production phase of product life cycle. Regarding to systematic shortening of design process and manufacturing, the main accent is put on application of CAD/CAM technologies for serial production of shaped-complicated parts. The aim of this paper is to show some aspects of actual trends in process of design and production in automotive industry.
13
Content available remote Numerical simulation of the hydraulic bulge test of HSLA steel and experimental verification of results
Slota J., Gajdos I.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2010
|
z. 81 [277]
67-72
EN
In sheet metal forming operations the mechanical properties of the sheet metal (stress-strain curve, flow stress) greatly influence metal flow and product quality. Accurate determination of the stress-strain relationship is important in process simulation by finite element method. In this paper the sheet thickness gradation in different points of the hemisphere formed in the bulge test is analyzed, both by simulation and experimentally. A precise determination of sheet thickness at the pole is very important in the precise determination of stress-strain relationship. The aim of this paper is to show on some aspects of numerical simulation of hydraulic bulge test and experimental verification of obtained results.
14
Content available remote Microstructure evaluation of TRIP steel used in a car crash zones
Oleksova M., Slota J., Herditzky A.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2010
|
z. 81 [277]
45-50
EN
The paper deals with evaluation of TRIP (transformation induced plasticity) steel microstructure. These special steels are commonly used mainly in automotive industry for crash zones of car's bodies. The TRIP steel has high strength compared to AHSS steel, but on the other hand a good plastic properties. The microstructure properties of TRIP steel were investigated by a light microscope and evaluated by a computer program ImageJ. Microstructure charakteristics of TRIP steel was investigated on shape-complicated part made by deep drawing process.
15
Content available remote Improving surface finish quality of FDM prototypes
Gajdos I., Slota J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2010
|
z. 80 [274]
87-90
EN
Rapid prototyping technologies decrease production time and costs in engineering industry but also in other industries. One of most widely used technology FDM suffers under low surface finish quality. This paper is aimed on research of surface finishing technologies applicable to improve the quality of FDM prototypes surface finish. Pretreated samples were blasted with sodium bicarbonate and glass beads. The values of Ra and Rz were measured on the samples and compared the impact of selected blasting medium and blasting conditions on surface finish quality of FDM prototypes.
16
Content available remote The scope of application of incremental rapid prototyping methods in foundry engineering
Stankiewicz M., Budzik G., Patrzałek M., Wieczorowski M., Grzelka M., Matysiak H., Slota J.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1 spec.
405--410
EN
The article presents the scope of application of selected incremental Rapid Prototyping methods in the process of manufacturing casting models, casting moulds and casts. The Rapid Prototyping methods (SL, SLA, FDM, 3DP, JS) are predominantly used for the production of models and model sets for casting moulds. The Rapid Tooling methods, such as: ZCast-3DP, ProMetalRCT and VoxelJet, enable the fabrication of casting moulds in the incremental process. The application of the RP methods in cast production makes it possible to speed up the prototype preparation process. This is particularly vital to elements of complex shapes. The time required for the manufacture of the model, the mould and the cast proper may vary from a few to several dozen hours.
17
Content available remote The application of optical measurements for the determination of accuracy of gear wheels casts manufactured in the RT/RP process
Budzik G., Oleksy M., Grzelka M., Wieczorowski M., Magniszewski M., Slota J.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1 spec.
395--398
EN
The article discusses the possibilities of using optical measurements for defining the geometric accuracy of gear wheels casts manufactured in the rapid prototyping process. The tested gear wheel prototype was cast using an aluminum alloy. The casting mould was made by means of the three-dimensional print method (3DP) with the use of a Z510 Spectrum device. The aim of the tests was to determine the geometric accuracy of the cast made by the ZCast technology in the rapid prototyping process. The tests were conducted with the use of the coordinate optical measuring method and a GOM measuring device. The prototype measurements were made in the scanning mode. The results of the measurements, saved in the STL format with the use of the scanning device software, were compared with the gear wheel 3D-CAD nominal model. The measurements enabled the determination of the real accuracy of prototypes manufactured in casting moulds by means of the ZCast technology. The selection of the measuring method was also analyzed in terms of measurement accuracy and the RP technology precision.
18
Content available remote The application of rapid prototyping, CAE and CAM methods in product development processes
Slota J., Gajdos I.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2008
|
z. 73 [253]
251-256
EN
In order to shorten manufacturing time for new products and their moulds, the use and the development of modern techniques are critical. One of such technologies is the rapid prototyping method, which enables to designers and customers to see the physical presentation of a new product. Application of the CAE methods is accentuated in the development phase of the product, which redounds to cost reducing on tools and moulds development. The paper deals with several steps in prototype development, the application of computer simulation by means of CAE system Moldflow MPI in mould development for mold plastic part and utilization of CAM system for NC programming of the mould manufacturing.
19
Content available remote Investigation of biaxial stress-strain relationship of steel sheet metal
Slota J., Spisak E., Stachowicz F.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no 1
161-168
EN
The stress-strain relationship of the deep drawing quality (DDQ) and intersitial free (IF) steel sheets was determined by uniaxial and equibiaxial (hydraulic bulging) tensile tests. The sheet thickness gradation in different points of the hemisphere formed in the bulge test was analysed, both experimentally and theoretically. The Hollomon equation was used to describe uniaxial and biaxial strain hardening curves, and the differential (strain dependent) strain hardening exponent nt was determined on the basis of the results of uniaxial and biaxial testing.
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