Wyniki wyszukiwania - BazTech

1

Influence exerted by the shape of the surfaces of working roll barrels upon the course of the MEFASS (Metal Forming Aided by Shear Stresses) rolling process

Świątoniowski A., Woźniak D., Szostak J.

Archives of Metallurgy and Materials

|

2017

|

Vol. 62, iss. 1

105--114

EN

The essential aspect of the MEFASS rolling process is introducing the cyclic axial counter movement of the rolls transverse to the direction of rolling in the course of a band pass through a rolling gap. The effect of a change in the way of deformation obtained in this manner makes it possible to set in one roll pass a deformation several times larger than it is possible in a conventional process. In this paper, upon the basis of the computer model of the MES process, supported by experimental research, the analysis of the influence exerted by the shape of the surface of roll barrels upon the distribution of the intensity of stresses σi and deformations εi in the section of the band being rolled, and also upon the kinematic and force parameters of the process.

2

Repair technology of the composite wing of a light plane damaged during an aircraft crash

Świątoniowski A., Szostak J., Chodorowska D.

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2016

|

z. 92

149--157

EN

The increasing use of composite structures in aircraft constructions has made it necessary to develop repair methods that will restore the component’s original design strength without compromising its structural integrity. In this paper, the complex repair technology of the composite wing of a light plane, which was damaged during an aircraft crash, is described. The applied repair scheme should meet all the original design requirements for the plane structure.

3

Corporate management through the lens of macroeconomics

Szostak J.

Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki

|

2015

|

Nr 3

103--117

EN

Organizational management processes reflect capital allocation in a given business as well as in the macroeconomic space at large. In practice, macroeconomic forces acting on a given economy will depend on economic policy pursued by the state. Under the currently prevalent neoliberal outlook on market economy and its mechanisms, the impact of macroeconomic forces is confined to creating a specific socio-economic environment in which businesses operate, and to defining the economic content of (the category of) production efficiency. The paper attempts to depict the influence of macroeconomic forces on the criteria for assessing business performance that impinge indirectly on corporate management processes. The discussion leads to a proposition that while macroeconomic policy founded on neoliberal premises might well be conducive to business activity, it could be, in the long run, detrimental to individuals and to society at large.

4

Struktury fotowoltaiczne z planarnym heterozłączem półprzewodnik II-VI / półprzewodnik molekularny

Signerski R., Jarosz G., Szostak J., Godlewski J.

Prace Instytutu Elektrotechniki

|

2014

|

Z. 264

91-98

PL

Artykuł przedstawia wybrane wyniki badań własnych nad układami hybrydowymi zbudowanymi na bazie złącza półprzewodnik nieorganiczny II-VI / półprzewodnik organiczny. Na podstawie analizy położenia pasm energetycznych warstw wchodzących w skład wytworzonych ogniw oraz charakterystyk spektralnych prądu zwarcia tych urządzeń, określone zostały procesy prowadzące do fotogeneracji nośników ładunku w badanych układach. W ogniwach zbudowanych na bazie złącz CdS/ZnPc oraz ZnTe/F16ZnPc zaobserwowano zarówno generację bezpośrednią w półprzewodniku nieorganicznym (przejście pasmo-pasmo), jak i generację wynikającą z dysocjacji ekscytonów wzbudzonych w półprzewodniku molekularnym, zachodzącą na złączu obydwu półprzewodników. W przypadku układów zbudowanych na bazie złącza CdTe/DIP, zaobserwowano jedynie fotogenerację drugiego typu.

EN

This article presents chosen results of research on hybrid solar cells based on inorganic II-VI semiconductor/molecular semiconductor heterojunctions. On the basis of energetic structure of fabricated devices and short-circuit current spectral response measured for these cells possible processes leading to photogeneration of free charge carriers were determined. For the cells based on CdS/ZnPc and ZnTe/F16ZnPc heterojunctions two processes were identified: direct photogeneretaion in inorganic semiconductors via band-to-band transitions and dissociation of excitons generated in molecular semiconductors that takes place at the interface of both semiconductors forming the junction. In contrast, only the latter process was observed in case of devices with CdTe/DIP heterojunction.

5

Jedno- i dwuwarstwowe organiczne ogniwa fotowoltaiczne

Godlewski J., Signerski R., Jarosz G., Obarowska M., Szostak J.

Prace Instytutu Elektrotechniki

|

2014

|

Z. 264

81-90

PL

Omówiona została zasada działania organicznych ogniw fotowoltaicznych na przykładzie ogniw jedno- i dwuwarstwowych. Przedstawione zostały procesy prowadzące do fotogeneracji swobodnych nośników ładunku w układach organicznych, ze szczególnym uwzględnieniem procesu dyfuzji oraz dysocjacji ekscytonu na złączu dwóch materiałów. Przytoczone zostały podstawowe wyrażenia na wartość napięcia fotowoltaicznego dla układów jedno- i dwuwarstwowych oraz wybrane wyniki badań własnych dla ogniw dwuwarstwowych.

EN

This article explains operational principles of organic solar cells for one-layer and bilayer planar devices. A short description of processes leading to photogeneration of free charge carriers, with special emphasis on exciton diffusion to a junction of two materials followed by exciton dissociation at this junction is given. Basic equations for photovoltage obtained for one- and bilayer devices are presented. Moreover, chosen results of research run by our group for bilayer planar solar cells are shown.

6

Theoretical and experimental analysis of roll bending of half ring of gas turbine

Świątoniowski A., Szostak J.

Journal of KONES

|

2014

|

Vol. 21, No. 2

289--294

EN

The article presents an analysis of forming half reinforcement ring housing the gas turbine. The ring is made of INCONEL alloy 617 material, which is based on nickel-chromium-cobalt-molybdenum alloy characterized by high strength and resistance to oxidation at high temperatures as 1100-1200°C. Square bar of dimensions 50x50 roll bending at half ring with a diameter of 1500 mm, an intermediate product is prepared for machining. The forming process is divided into two operation. The first operation is to pre-bending the rod. The second operation is to roll bending to the radius determined by the deflection. The article presents the map of reduced stress of HMH for two operations, obtained from the numerical simulation based on the finite element method. It also presents the load on the tools during the entire process. Physical tests were carried out on the device for roll bending steel profiles DURMA PBH 125. The article sets out the minimum allowances technology needed to complete half of the ring. A comparison of deviations, outside diameter of the ring, was resulting from the spring back in the study of physical and numerical simulations. We also compared the flatness deviation of the ring resulting in the research. The results of theoretical research have confirmed good agreement with physical examinations. The research provided an opportunity to develop technologies forming of half ring on the above machine of bending steel profiles

7

Analysis forming the diameter reduction of the tube to the cylinder hydraulic shock absorber

Świątoniowski A., Szostak J., Gomułka K.

Journal of KONES

|

2014

|

Vol. 21, No. 1

281--286

EN

The article presents the process of reducing the pipe and the influence of the shape of the tool on the geometric parameters of the cylinder. Charge material tube is precision welded cold drawn with an outer diameter ø 57 mm, made of stainless E355. Reduced pipe is used for cylinder hydraulic shock absorber. Formed cylinder is part of the structure MacPherson strut front suspension vehicle. Tube reduction process is carried out with cold working by using a hydraulic press. Analysed the influence of the diameter of the tool ø and profile angle 􀄮 transition into basic the geometric parameters of the deformed cylinder: inner diameter, wall thickness, pipe cylindrical deviation effect. The result of numerical simulation is a map of HMH stress. As well as the effect of the transition profile, angle the value of the tool diameter of the inner pipe, wall thickness and the value of cylindrical deviation effect. In this paper a comparative analysis of the outer diameter, inside diameter and cylindrical deviation effect for physical and numerical studies. Simulation of reduce tubes was carried out with DEFORM 3D software based on the finite element method. Numerical analysis allowed for a detailed knowledge of the specifics of the process and a comprehensive analysis of phenomena that are not possible to explore traditional methods.

8

Analysis of Kinematic and Force Parameters of the Die-Forging Process Performed on a CrNiN Alloy

Świątonowski A., Szostak J.

Journal of Machine Engineering

|

2013

|

Vol. 13, No. 4

57--67

EN

This article presents the results of studies of simulations of die forging of a drive shaft for small and medium watercraft. The formed material is a chromium and nickel alloy endogenically modified with nitrogen. Numerical simulations were carried out using the DEFORM-3D program, by means of which a map of mean stresses, temperature, deformation intensity, and cracking according to the Cockroft-Latham model were obtained. The results of the conducted studies will enable selection of the appropriate technological parameters in the process of forging CrNiN alloys.

9

Zastosowanie walców z węglików spiekanych w procesach walcowania blach o wysokiej wytrzymałości

Świątoniowski A., Szostak J., Woźniak D.

Hutnik, Wiadomości Hutnicze

|

2013

|

Vol. 80, nr 9

661--664

PL

Stosując oprogramowanie typu MES, jakim jest Ansys 11, przedstawiono analizę stanu naprężeń i odkształceń w wykonanym z węglika spiekanego walcu roboczym sześciowalcowej walcarki do walcowania ultratwardych blach cienkich na zimno. Stwierdzono iż zasadniczym problemem w utrzymaniu założonego przedziału tolerancji grubości pasma po odkształceniu – równego ±0,5% nominalnego wymiaru grubości h1 są odkształcenia kontaktowe na powierzchni styku walców roboczych i oporowych. Odkształcenia te pozostają też znaczące w strefie styku walca roboczego z materiałem.

EN

Work contains analysis of condition of strain and stress in working roller made of sintered carbides in six roller mill for cold rolling ultrahard metal, based on FEM Ansys 11software pack. It has been certified that basic problem in keeping the right range of tolerance of strip thickness after deformation equal ± 0.5% of nominal dimension h1 are contact deformation on contact surface of working and resistant roller. Anyhow these deformations are significant between the working roller surface and material.

10

Organic photovoltaics : chosen aspects

Szostak J., Signerski R., Żelechowska K., Godlewski J.

Elektronika : konstrukcje, technologie, zastosowania

|

2012

|

Vol. 53, nr 6

118-120

EN

There are many types of organic and organic/inorganic (hybrid) photovoltaic devices that possess many beneficial properties over inorganic solar cells. That makes the former suitable for a broad range of applications and hence so much attention is paid to their development. In spite of intensive research carried on this field of science and technology there are still many crucial problems that need to be solved. Extensive knowledge on physical basis of operation of organic and hybrid systems, fast development of nanotechnology, great variety of organic materials and methods of their modification will pave the way for commercial applications of these devices.

11

Wpływ temperatury i prędkości odkształcenia na naprężenia uplastyczniające stopu CrNiN

Sińczak J., Świątoniowski A., Schmidt J., Szostak J.

Rudy i Metale Nieżelazne

|

2008

|

R. 53, nr 7

418-424

PL

Postęp w konstrukcji i eksploatacji maszyn pozostaje dziś w znacznym stopniu zdeterminowany przez użycie nowych materiałów i technologii. W artykule omówiono jeden z takich właśnie materiałów - stop CrNiN. Jest to stop na bazie chromu i niklu endogenicznie modyfikowany azotem i pierwiastkami tworzącymi azotki. Pierwiastki te oraz azot mogą w procesie wytopu i odlewania oddziaływać ze sobą, tworząc w strukturze wydzielenia w postaci azotków tytanu. W celu określenia zdolności stopu CrNiN do odkształceń plastycznych wykonano badania na symulatorze Gleeble 3800. Uzyskane krzywe umocnienia posłużyły do wykonania symulacji komputerowych procesu spęczania przy warunkach brzegowych zgodnych z rzeczywistymi. Wyznaczono rozkłady odkształceń i naprężeń w procesie spęczania badanego stopu, umożliwiające podejmowanie decyzji związanych z możliwym zakresem i rodzajem procesów przeróbki plastycznej.

EN

Nowadays progress in machine construction and its exploitations are mostly determined by using new materials and technology. In this study one of the example of such a material - CrNiN-alloy has been presented. These alloy represent chromium and nickel basis alloyed by nitrogen and nitrides forming elements, which under suitable conditions could react between themselves forming nitrides particles. At the aim of determine the plastic property of the CrNiN alloy some tests have been made using Gleeble 3800 thermo-mechanical simulator. On the basis of the work hardening curve obtained that way numerical simulation of the upset forging have been made taking into account the real boundary conditions of the process. Stress pattern as well as plastic strain distributions have been also obtained. This enable to decide about possible range of the CrNiN alloy plastic deformation process.

12

Nieinwazyjna diagnostyka obwodów wirnika maszyny synchronicznej

Weinreb K., Węgiel T., Szostak J.

Maszyny Elektryczne : zeszyty problemowe

|

2003

|

Nr 66

75-80

EN

The solution of mathematical equations for salient-pole machine described in symmetrical components using predictable method and harmonic balance method permit to find harmonic sets for current of excitation winding. This method is useful in symmetrical steady state, in case of eccentricity of the rotor and broken rotor windings. The simulation of failure in rotor winding, as well as in cage, allows quantitative calculation coefficients which represent type of damages. In present paper, on the example of salient-pole synchronous generator with special construction designed for noninvasive diagnostic, the results of measured tests which verify the method of rotor defects estimation are shown. Presented results give a possibility of qualitative and quantitative Fourier spectrum estimation of excitation winding current for different kinds of rotor windings damages.