Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Nikolić, R. R." wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-10 z 19
Tytuł:
Buckling of variable cross-sections columns in the braced and sway plane frames
Autorzy:
Nikolić, R. R.
Djoković, J. M.
Bujňák, J.
Powiązania:
https://bibliotekanauki.pl/articles/131574.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Komisja Inżynierii Budowlanej PAN Oddział w Katowicach
Tematy:
columns
variable cross-section
buckling
structural stability
kolumny
przekrój poprzeczny
wyboczenie
stabilność strukturalna
Opis:
Columns of the variable cross-sections are used in order to decrease the costs of the structure, for the purpose of easier maintenance, or for architectural reasons. Buckling of such columns is a problem that could appear in many steel structures, and could cause the loss of the structural stability. The critical buckling loading and the effective buckling lengths of such columns are analyzed in this paper for the cases of columns in the braced frame with the fixed and the sway frame with the movable nodes. Results are presented on corresponding diagrams what enables pinpointing the exact moment at which the particular column would lose its stability. The comparison of obtained results for the two types of frames are presented, as well.
Źródło:
Roczniki Inżynierii Budowlanej; 2016, 16; 31-39
1505-8425
Pojawia się w:
Roczniki Inżynierii Budowlanej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The fatigue life estimate by the LEFM concept of the tube joints exposed to axial load
Autorzy:
Djoković, J. M.
Nikolić, R. R.
Bujňák, J.
Hadzima, B.
Powiązania:
https://bibliotekanauki.pl/articles/131470.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Komisja Inżynierii Budowlanej PAN Oddział w Katowicach
Tematy:
tube joints
fatigue life
LEFM
Paris' law
złącza rurowe
trwałość zmęczeniowa
prawo paryskie
Opis:
In the tube joints the crack growth usually appears along the weld’s edge, i.e. at the spot where the chord and the brace are connected. The semi-elliptical crack the most frequently develops from the initial flaw that originated during the welding. The abrupt change in the material’s structure and response to loading are increasing the normal stresses in the lateral tube at certain spots around the crossing of the main and lateral tubes, producing the “hot spot” stress. Sensitivity to fatigue depends on combination of the cyclic loading, initial defects, environmental influences and the “hot spot” stresses which are the result of the tube walls bending during the loading of the structure. The principles of the Linear Elastic Fracture Mechanics (LEFM) are applied in this paper to analysis of the crack propagation behavior of a thin tube joints. Influence of various parameters was investigated individually and independently, and the share of the fatigue crack growth and subsequently the working life of the welded joint were estimated.
Źródło:
Roczniki Inżynierii Budowlanej; 2017, 17; 35-41
1505-8425
Pojawia się w:
Roczniki Inżynierii Budowlanej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the LEFM concept for interfacial cracks application to coating buckling delamination in terms of substrate elastic characteristics
Autorzy:
Djoković, J. M.
Nikolić, R. R.
Miletić, I. M.
Mićunović, M. V.
Powiązania:
https://bibliotekanauki.pl/articles/280976.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
coating
buckling delamination
LEFM concept
interfacial cracks
Opis:
In this paper the buckling delamination of a coating on a flat substrate in form of a straightsided blister with special attention paid to the influence of elastic characteristics of the substrate is considered. Conditions for the buckling initiation are analyzed as well as the energy release rate and mode mixity of the interface crack as functions of the difference in elastic characteristics of the coating and the substrate. The problem is discussed from the aspect of application of the linear elastic fracture mechanics (LEFM) concept for the interfacial crack. The real angle function ! of the Dundurs parameters and and the ratio of thicknesses of the two layers are used for determination of the energy release rate and the load phase angle. Both the energy release rate along the sides of the blister and the average energy release rate at the front of the blister were calculated. The results thus obtained justify the application of the LEFM concept for interfacial cracks to the considered problem.
Źródło:
Journal of Theoretical and Applied Mechanics; 2014, 52, 1; 61-69
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites
Autorzy:
Veličković, S.
Miladinović, S.
Stojanović, B.
Nikolić, R. R.
Hadzima, B.
Arsić, D.
Powiązania:
https://bibliotekanauki.pl/articles/111714.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
aluminum alloy
hybrid composites
silicon carbide
graphite
particles
stop aluminium
węglik krzemu
grafit
kompozyty hybrydowe
Opis:
Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.
Źródło:
Production Engineering Archives; 2018, 18; 18-23
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of analytical and the FEM method for deriving the Mode I stress intensity factor of thin-walled beams containing a crack
Autorzy:
Djoković, J. M.
Vulović, S. D.
Nikolić, R. R.
Živković, M. M.
Bujnak, J.
Powiązania:
https://bibliotekanauki.pl/articles/131642.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Komisja Inżynierii Budowlanej PAN Oddział w Katowicach
Tematy:
cracked thin-walled beams
modeI SIF
cross-section warping
FEM
J-EDI
belka cienkościenna
współczynnik intensywności naprężeń
MES
Opis:
The problem considered in this paper is of the cracked thin-walled beams. They are subjected to combined loading by the bending moment and the axial force. The profiles with the I (H), T and U cross-sections were analyzed. The analytical method is based on application of classical expressions for Mode I SIF of such beams with taking into account the cross sections' warping. The classical expressions for SIF for the thin plate are adapted by including the reduced forces and moments characteristic for the thin-walled beams. The numerical simulation for calculating the stress intensity factor of the cracked thin-walled beams consisted of application of the Finite Element Method (FEM) by use of the J-EDI method. It is found that the Mode I SIF of cracked thin-walled beams increases with crack length increase. The conducted comparison of results obtained by application of the two methods confirms the validity of the proposed analytical expressions only for the small crack lengths.
Źródło:
Roczniki Inżynierii Budowlanej; 2015, 15; 43-51
1505-8425
Pojawia się w:
Roczniki Inżynierii Budowlanej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reparation of damaged forging dies by hard facing (HF) technology
Autorzy:
Lazic, V.
Arsic, D.
Nikolic, R. R.
Aleksandrovic, S.
Milosavljevic, D.
Djordjevic, M.
Cukic, R.
Powiązania:
https://bibliotekanauki.pl/articles/111606.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
forging dies
hard facing (HF)
filler metals (FM)
hardness
microstructure
matryce kuźnicze
napawanie
spoiwa
twardość
mikrostruktura
Opis:
The forging dies are in exploitation exposed to elevated temperatures and variable impact loads, both compressive and shear. Steels for manufacturing of these tools must endure those loads while maintaining mechanical properties and being resistant to wear and thermal fatigue. For those reasons, the alloyed steels are used for making the forging dies, though they have less weldability, because alloying increases proneness to hardening. Any reparatory hard facing (HF) of the damaged dies would require the specially adjusted technology to the particular piece. In this paper reparatory hard facing of dies used for forging pieces in the automobile industry is considered. Prior to reparatory hard facing of the real tools, numerous experimental hard facings on models were performed. All the model hard facings were done on the same steels which were used for production of the real forging dies. To define the optimal hard facing technology one needs to derive the optimal combination of the adequate heat treatment(s), to select the proper filler metals and the welding procedure. The established optimal HF technology was applied to real forging dies whose service life was further monitored in conditions of exploitation.
Źródło:
Production Engineering Archives; 2015, 6, 1; 26-29
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vitamin and mineral content in black currant (Ribes nigrum L.) fruits as affected by soil management system
Autorzy:
Paunović, S.M.
Nikolić, M.
Miletić, R.
Mašković, P.
Powiązania:
https://bibliotekanauki.pl/articles/11543572.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
Black currant contain significant amounts of minerals and vitamins that are associated with an improved health status. The effect of three soil management system (bare fallow, sawdust mulch and black foil mulch) on the content of vitamins and minerals in the fruits of seven black currant cultivars (‘Ben Lomond’, ‘Ben Sarek’, ‘Titania’, ‘Čačanska Crna’, ‘Tisel’, ‘Tiben’ and ‘Tsema’) was analyzed. HPLC-DAD (high performance liquid chromatography-diode array detector) technique was used to define the vitamins A, B1, B2 and B3. Vitamin C were evaluated using a spectrometer, whereas the mineral content of the fruit was determined by flame atomic absorption spectrometry. Significant differences in the minerals and vitamins content were detected among the cultivars. The berries of black currants are rich in mineral composition, especially potassium, phosphours, sodium, calcium and magnesium as well as iron. Also, black currant is an important source of vitamin C and, to a lesser amount vitamins A and B3. Soil management systems showed highly significant differences in some the tested parameters. Black currants grown on black foil mulch gave the highest levels of K, P and Na, and those on sawdust mulch had a high content of vitamins C, A and B3. On the other hand, soil management system had no pronounced effect on the other vitamins and minerals analyzed. This study demonstrates degree of differences in the amount vitamins and mineral elements depending on the different soil management systems and climatic factors.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2017, 16, 5; 135-144
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of welding time on quality of the friction welded joint of two dissimilar steels
Autorzy:
Ratković, N.
Lazić, V.
Arsić, D.
Nikolić, R.
Hadzima, B.
Powiązania:
https://bibliotekanauki.pl/articles/114836.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
friction welding
joint quality
welding time
friction time
compacting time
spawanie tarciowe
jakość połączenia
czas spawania
czas tarcia
Opis:
There are several factors that influence the friction welding (FW) process, i.e. the quality of the welded joint, like the welding time, the contact pressure, the compacting pressure, the friction speed etc. The joining process is additionally complicated if the two different materials are to be welded to each other. The subject of research, presented in this paper, is the welding time of the FW process, since the level of axial and radial plastic deformation of the welded pieces and shortening of the welded part depend mainly on the welding time. The paper first presents some theoretical basics of the FW process and then, in the experimental part, the influence of the process duration is investigated. The two materials that the experimental samples were made of are the high-speed steel and the steel for tempering.
Źródło:
Zeszyty Naukowe. Quality. Production. Improvement; 2017, 1 (6); 1-11
2544-2813
Pojawia się w:
Zeszyty Naukowe. Quality. Production. Improvement
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Revitalization of the damaged machine parts by hard facing as a way of saving funds
Autorzy:
Lazic, V.
Arsic, D.
Nikolic, R.
Mutavzic, M.
Hadzima, B.
Powiązania:
https://bibliotekanauki.pl/articles/111734.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
revitalization technology
hard facing
costs
savings
profitability
loader's bucket teeth
technologia rewitalizacji
napawanie
rentowność
ładowarka
Opis:
The objective of the research, presented in this paper, was to demonstrate the superiority of the hard facing as the revitalization technology of various damaged machine parts. The analysis of the two different revitalization methods of the damaged machine parts is presented – the replacement of the damaged part by the new – spare part and reparation by hard facing. The comparison is done on the example of hard facing and replacing of damaged loader's teeth. The paper presents a method for calculating costs of the two revitalization technologies based on their profitability and their comparison. That method could be applied for similar calculations for any machine part, with smallest or no adjustments. The paper presents a verification of advantage of applying the hard facing as the machine parts reparatory technology with respect to the other revitalization technology. The savings realized by application of hard facing reparation of the loader's teeth reach 73.5 % for one set of teeth and 82.40per annum of the costs for purchasing the new spare parts. The analysis was conducted under an assumption that organization of the maintenance function is at the exceptionally high level so that the purchasing of the new part/repairing of the damaged one is always done in time. This idealized approach was adopted since in that way one obtains the least economic effects of the reparatory technology application with respect to replacing the part with the spare one. In any other case the economic effects would be significantly higher, namely even more positive in favor of the hard facing revitalization technology.
Źródło:
Production Engineering Archives; 2016, 12, 3; 9-13
2353-5156
2353-7779
Pojawia się w:
Production Engineering Archives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of work-related injuries in mining industry in Serbia
Autorzy:
Ivaz, Jelena
Petrović, Dejan
Nikolić, Ružica R.
Djoković, Jelena M.
Powiązania:
https://bibliotekanauki.pl/articles/88464.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
mining industry
safety
work-related injuries
absence from work due to injury
przemysł wydobywczy
bezpieczeństwo
wypadek przy pracy
bezpieczeństwo i higiena pracy
absencja powypadkowa
Opis:
The mining industry in Serbia has an important place in the country's economic development. Bearing in mind that the number of injuries that occur in the mining industry is unacceptably high, occupational safety and health is a challenge that existing and future mines will have to deal with. Studying injuries in mining, it was noticed that injuries requiring an absence from work for more than three days (especially fatal ones) are diametrically different in relation to the cause and manner of events related to injuries for which an absence from work is not necessary. In this research, authors focused on injuries that were characterized as ones requiring an absence from work. The statistical analysis of work-related injuries in mining is presented, as well as analysis of the direct causes of injuries, which are described as unsafe conduct of employees, unsafe conduct of company's management and/or unsafe working environment. In relation to classification of causes of injuries, a recommendation on what needs to be changed in order to remedy this situation in Serbia is given.
Źródło:
System Safety : Human - Technical Facility - Environment; 2020, 2, 1; 158-165
2657-5450
Pojawia się w:
System Safety : Human - Technical Facility - Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-10 z 19

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies