11 results on '"Kubiak, Marcin"'
Search Results
2. Issues in Numerical Modeling of Phase Transformations in Welded Joint.
- Author
-
Piekarska, Wiesława, Kubiak, Marcin, and Żmindak, Milan
- Subjects
PHASE transitions ,WELDING ,HEATING ,COOLING ,MATHEMATICAL analysis - Abstract
This work concerns issues of mathematical modelling of phase transformations in steels during a high-speed high-power heat source welding processes. The analysis of the influence of thermal cycle parameters such as: heating rate, cooling rate and the maximal heating temperature on the kinetics of phase transformations during heating and cooling is performed. The verification of classical mathematical and numerical models of phase transformations is presented in relation to advanced welding methods using a high-speed high-power heat source on the basis of data found in the literature and experimental research. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
3. Numerical Modelling of Mechanical Phenomena in the Gantry Crane Beam.
- Author
-
Sowa, Leszek, Saternus, Zbigniew, and Kubiak, Marcin
- Subjects
GANTRY cranes ,COMPUTER simulation ,FINITE element method ,STRAINS & stresses (Mechanics) ,COMPUTER software - Abstract
The mathematical model and numerical simulations of the mechanical phenomena in the gantry crane are presented in this paper. The design of modern mechanical constructions is a complex task that requires use of appropriate tools. Such a modern tool, that gives a broad opportunity to analyze strength parameters of designed structures, is numerical simulation which uses the various numerical methods. Here the problem was solved by the finite element method. The analysis of the stresses and strains of the structure of gantry crane was made using the advanced software with highly efficient possibilities of modeling. Motion of the crane trolley along the beam was also taken into account in the study. The research performed, allows the evaluation of the stress state, pointing out the critical areas and values which are made in order to increase the strength of the structure of the gantry crane. The results of numerical simulation are presented in the form of the fields of Huber-Misses stress for the selected location of the crane trolley. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
4. Measurement of Strain During Tension Test of Welded Joint Using Multi-camera 3D Correlation System.
- Author
-
Kubiak, Marcin, Domański, Tomasz, Dekýš, Vladimír, and Sapietová, Alžbeta
- Subjects
WELDED joints ,STRAINS & stresses (Mechanics) ,WELDING ,TENSILE tests ,YAG lasers - Abstract
This work concerns experimental research on the determination of deformation during uniaxial tension test of samples made of laser-arc hybrid welded joints. Steel sheet made of S355 steel with thickness 5 mm is butt-welded without gap using hybrid welding technique involving GMAW method with Yb:YAG laser beam. Samples used to the tension test are made from welded joints and base material. Universal strength machine Zwick&Roel Z100 is used with extensometer Multisens in all performed tension tests. The machine works with Dantec Q-400 Istra multi-camera 3D correlation system. System of three cameras mounted on a beam line is used for accurate measurement of the spatial deformations. Presented results of the research include strain fields measured for the entire tension cycle at the frequency 40 Hz. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
5. Numerical Estimation of the Shape of Weld and Heat Affected Zone in Laser-arc Hybrid Welded Joints.
- Author
-
Piekarska, Wiesława, Kubiak, Marcin, and Vaško, Milan
- Subjects
WELDED joints ,NUMERICAL analysis ,TEMPERATURE ,ENERGY conservation ,INTERPOLATION - Abstract
Numerical modeling of thermal phenomena with the motion of fusion zone in the welding pool taken into account is performed in this study for hybrid welding process using Yb:YAG laser with electric arc in GMAW method. New hybrid heat source model is developed on the basis of classical Goldak model for the electric arc and interpolation model for the laser beam with the experimental data of Yb:YAG laser beam distribution taken into account. Temperature field and melted material velocity field are calculated on the basis of numerical solution into mass, momentum and energy conservation equations in finite volume method with Chorin's projection method. Computer simulations of temperature field and melted material velocity field are performed in the welding pool for different distances between heat sources. The comparison of numerically estimated geometry of characteristic zones of joints with macroscopic pictures of cross sections of welds is made in order to evaluate the suitability of developed numerical model in industrial applications. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. Determination of the Final Microstructure during Processing Carbon Steel Hardening.
- Author
-
Domański, Tomasz, Piekarska, Wiesława, Kubiak, Marcin, and Saternus, Zbigniew
- Subjects
CARBON steel ,METAL hardness ,METAL microstructure ,HEAT treatment of metals ,NUMERICAL analysis - Abstract
Numerical analysis of thermal treatment processes is an important issue to be considered by contemporary laboratories dealing with industrial designing in general. Phenomena associated with heat treatment are complex and not yet adequately explained. Improvement in this field of numerical solutions is particularly forced by industry which, striving for deployment of state of the art technologies and reduction of costs, is demanding continuous enhancement of tool thermal treatment. Phase transformations, in particular in cooling processes, involve considerable changes in kinetics that are not always associated with external thermal impact. Analyses of experimental data allowed developing many mathematical models to measure volume fractions of phase transformations in solid state. The Johnson-Mehl Avrami equation and generalised Kolmogorov equation are the two primary models applied in almost all tests evaluating transformation of austenite into ferrite, bainite and martensite. In order to calculate the martensitic phase volume fraction, usually the Koistinen-Marburger equation, or any of its modified formulas, are used. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
7. Numerical Analysis of Deformations in Sheets Made of X5CRNI18-10 Steel Welded by a Hybrid Laser-arc Heat Source.
- Author
-
Saternus, Zbigniew, Piekarska, Wiesława, Kubiak, Marcin, Domański, Tomasz, and Sowa, Leszek
- Subjects
NUMERICAL analysis ,DEFORMATIONS (Mechanics) ,LASER arc welding ,WELDING ,PARAMETER estimation ,INTERFACES (Physical sciences) ,DISTRIBUTION (Probability theory) - Abstract
The laser-arc hybrid welding is widely used in many industries through the combination of advantages found in welding technologies used in this single process. A significant issue is the determination of the influence of heat source power distribution on welding deformations generated at the interface of joined elements and adjacent zones. Numerical estimation of welding deformations is very important and allows for the proper selection of technological parameters as well as the prediction of welded joints quality. This work concerns numerical simulation of thermomechanical phenomena in hybrid welding of sheets made of X5CRNI18-10 steel using laser beam and electric arc heat sources. Three dimensional discrete model is created in Abaqus FEA in order to estimate welding deformations generated by temperature field in the joint. Additional numerical subroutine is created in Abaqus/Standard module in which the distribution of movable hybrid heat source is implemented. The shape and size of the fusion zone is determined on the basis of numerically obtained temperature field as well as welding deformations occurring in hybrid butt-welded joints. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
8. Numerical Prediction of Fusion Zone and Heat Affected Zone in Hybrid Yb:YAG laser + GMAW Welding Process with Experimental Verification.
- Author
-
Kubiak, Marcin, Piekarska, Wiesława, Saternus, Zbigniew, and Domański, Tomasz
- Subjects
LOGICAL prediction ,FUSION (Phase transformation) ,HYBRID systems ,GAS metal arc welding ,PHYSICS experiments ,NUMERICAL analysis - Abstract
This work concerns mathematical and numerical modelling of temperature field during hybrid welding process using Yb:YAG laser and electric arc in GMAW method. Numerical analysis is performed taking into account the motion of liquid steel in the fusion zone. Yb:YAG laser power distribution is determined on the basis of experimental research made on TruDisk 12002 laser. Geostatistical Kriging method is used in the interpolation of Yb:YAG laser power intensity distribution. Temperature field and melted material velocity field in the fusion zone of hybrid welded sheets made of S355 steel are obtained on the basis of numerical solution of continuum mechanics equations in Chorin's projection method and finite volume method. Experimental research of laser beam profile is performed in order to verify the correctness of developed heat source model. Fusion zone and heat affected zone geometry is predicted on the basis of calculated temperature field in the cross section of hybrid welded joint. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
9. Atypical lipomatous tumor of the cheek – a case report
- Author
-
Kaczmarczyk, Dariusz, Jesionek-Kupnicka, Dorota, Kubiak, Marcin, and Morawiec-Sztandera, Alina
- Abstract
Liposarcoma is the most common soft tissue malignant tumor. It mostly arises in the subcutaneous tissue of shoulders, limbs and neck, and retroperitoneal space, but head occurrence is very rare. Atypical lipomatous tumor (ALT) is a well-differentiated liposarcoma (WDLPS) and constitutes 40–45% of all liposarcoma cases. A case of 57-year-old woman with a tumor of the left cheek, causing a discreet face asymmetry is presented. The tumor was soft and caused no tenderness. The patient reported no previous injury of the region. Fine-needle aspiration biopsy (FNAB) revealed atypical cells suspected of liposarcoma. MR examination showed fascicles of adipose tissue, which made the left cheek prominent. The patient was operated under general anaesthesia. Adipose tissue of the left cheek was removed. Postoperative course was uneventful. The final histopathological diagnosis – was atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLPS). The patient remains under laryngological care. No recurrence of the disease has been observed during the 5 years follow-up.
- Published
- 2013
- Full Text
- View/download PDF
10. Leczenie chirurgiczne guzów nowotworowych slinianek
- Author
-
Kubiak, Marcin, Lapienis, Magdalena Maria, Kaczmarczyk, Dariusz, and Morawiec-Sztandera, Alina
- Abstract
Tumors of parotid gland represent a diverse group of neoplasms with varied clinical behaviors.
- Published
- 2008
- Full Text
- View/download PDF
11. The Araucaria Project: A Wide-Field Photometric Survey for Cepheid Variables in NGC 3109
- Author
-
Pietrzynski, Grzegorz, Gieren, Wolfgang, Udalski, Andrzej, Soszynski, Igor, Bresolin, Fabio, Kudritzki, Peter, Mennickent, Ronald, Kubiak, Marcin, Szymanski, Michal, and Hidalgo, Sebastian
- Abstract
We have obtained mosaic images of NGC 3109 in the V and I bands on 74 nights, spanning approximately 1 yr. From these data, we have conducted an extensive search for Cepheid variables over the entire field of the galaxy, resulting in the discovery of 113 variables with periods ranging from 3.4 to 31.4 days. In this sample, 76 Cepheids, including many long-period variables, were not known before. For the previously known 45 Cepheids in this galaxy, our data proved that reported periods were wrong for 14 objects; for nearly all other previously known Cepheid variables, we were able to significantly improve on the periods. We construct period-luminosity relations from our data and obtain reddening-corrected distance moduli of 25.72 +- 0.03 mag in V and 25.66 +- 0.03 mag in I. The distance modulus derived from the reddening-independent V-I Wesenheit index turns out to be significantly shorter (25.54 +- 0.03 mag), which indicates that in addition to the foreground extinction of E(B-V) = 0.05 mag, there is an intrinsic to NGC 3109 reddening of about 0.05 mag. Our distance obtained based on the reddening-free Wesenheit magnitudes is consistent with earlier distance determinations of NGC 3109 from Cepheids and the tip of the red giant branch. We improve on our distance and extinction determination combining our optical data with the follow-up near-infrared observations of a subsample of NGC 3109 Cepheids.
- Published
- 2006
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.