dc.contributor.advisor | Todorović, Petar | |
dc.contributor.other | Mačužić, Ivan | |
dc.contributor.other | Xenos, Thomas | |
dc.contributor.other | Mitrović, Slobodan | |
dc.contributor.other | Milisavljević, Stevan | |
dc.creator | Tsiafis, Christos I. | |
dc.date.accessioned | 2019-03-25T12:54:30Z | |
dc.date.available | 2019-03-25T12:54:30Z | |
dc.date.available | 2020-07-03T15:13:02Z | |
dc.date.issued | 2018-12-07 | |
dc.identifier.uri | http://eteze.kg.ac.rs/application/showtheses?thesesId=6552 | |
dc.identifier.uri | https://nardus.mpn.gov.rs/handle/123456789/10940 | |
dc.identifier.uri | https://fedorakg.kg.ac.rs/fedora/get/o:1069/bdef:Content/download | |
dc.description.abstract | Rezime:
Od samih početaka industrijske revolucije pojavila se potreba za što
efikasnijom i pre svega jeftinijom proizvodnjom proizvoda koja će pri tom imati
željeni visok nivo kvaliteta. U tu svrhu, kreiraju se sve brže i snažnije mašine
i mehanizmi, koji postaju sve kompleksniji, a samim tim izloženiji višim
nivoima opterećenja. Kao rezultat toga mašine su sve više izložene
kompleksnijim tipovima oštećenja i/ili otkazima koji direktno utiču na njihovu
pouzdanost, raspoloživost i bezbednost pri korišćenju. Takvu opremu srećemo u
finansijski i tehnički posebno kritičnim oblastima kao što su: procesi obrade,
transportni sistemi, električna i elektronska oprema, elektroenergetski
sistemi, a u novije vreme su to sistemi za proizvodnju obnovljive energije.
Rotacione mašine spadaju u klasu najčešće korišćenih tehničkih sistema, za
koje se često zahteva kompletna i precizna dokumentacija o vibracionim
karakteristikama, uključujući merenja neophodna kako bi se izvršila analiza
vibracija vratila, kućišta i kotrljajnih ležajeva. Kotrljajni ležajevi,
reduktori i rotori su ključne i neizostavne komponente rotacionih mašina.
Samim tim, stanje ovih ključnih komponenata ujedno određuje i stanje same
rotacione mašine.
U disertaciji se proučava primena postprocesionih metoda izdvajanja spektra iz
signala vibracija, kako bi se detektovala oštećenja kotrljajnih ležajeva.
Kotrljajni ležajevi su osnovne komponente rotacionih mašina. Oštećenja
kotrljajnih ležajeva su odgovorna za značajan deo otkaza mašina. Samim tim
otkrivanje oštećenja kotrljajnih ležajeva je važno za poboljšanje pouzdanosti i
performansi mehaničkih sistema.
Iako su kotrljajni ležajevi detaljno proučavani tokom prethodnih decenija što
je prikazano u dostupnoj literaturi, u ovoj disertaciji je predstavljena
inovativna primena vremensko–frekvencijske metode za analizu, tzv. metode
kompletne ansambalske empirijske dekompozicije na modove sa adaptivnim
šumom (eng. Complete Ensemble Empirical Mode Decomposition with Adaptive Noise –
CEEMDAN) i Zao–Atlas–Markove raspodele (ZAMD). Pomenutim metodama se
prevazilaze poznata ograničenja metode razlaganja signala na funkcije (eng.
Empirical Mode Decomposition – EMD), u pogledu mešanja modova i izdvajanja
frekvencija. Glavni cilj disertacije je istraživanje sposobnosti ovih metoda za
otkrivanje oštećenja u početnoj fazi. Za procenu metoda, koriste se kotrljajni
ležajevi sa poznatim lokalizovanim oštećenjima, u cilju dobijanja skupa
podataka sa eksperimentalnog postrojenja koje simulira rotacionu mašinu. Isto
tako, upotrebljavaju se i podaci iz literature kao drugi test. Dobijeni rezultati
potvrđuju sposobnost metode za otkrivanje degradacije kotrljajnih ležajeva. | sr |
dc.description.abstract | Abstract:
Since the industrial revolution, a need for faster, better quality and especially cheaper to
produce, products has emerged. So special tools, quick and powerful machines and
mechanisms were created, and tend to become increasingly complex, thus subject to a
corresponding complex damage and / or failures affecting the reliability, availability and
safety of operation. Such equipment’s are found in particularly critical financial and
technical fields such as machining processes, production, transport systems, electrical and
electronic equipment and power systems (and, recently, renewable energy). Rotating
machinery is one of the most common classes of machines, often requires complete and
accurate documentation of vibration characteristics including measurements for shaft,
housing and rolling bearings vibration analysis. Rolling bearings, gears and rotors are the
common and key components in rotating machinery. The health condition of these key
components represents that of the machine itself.
The present dissertation introduces investigates the application of a post-processing
method of extracting spectra from vibration signals in order to detect faults of rollingelement
bearings. Rolling-element bearings are fundamental components of rotating
machinery. Faults of rolling-elements bearings are responsible for a substantial
proportion of machine failures and therefore fault detection is important for improving
the mechanical system reliability and performance. Although rolling bearings have been
investigated in detail in past studies, innovative applications of time-frequency analysis
method, called complete ensemble empirical mode decomposition with adaptive noise
(CEEMDAN) and Zhao Atlas Marks Distribution (ZAMD), that overcomes known
limitations concerning mode mixing and frequency separation of empirical mode
decomposition are presented. The main aim of the presented dissertation is to investigate
the ability of the methods to detect faults in early stage. To validate the methods, rollingelement
bearings with known and localized faults are used in order to acquire datasets
from an experimental rig that stimulates rotating machinery. Also datasets from literature
are used as second trial. The results verify the ability of the method to detect degradations
of rolling-element bearings.
The present dissertation consists of six experimental studies and one industrial case study,
where the first one was concerned with investigation and validation of the experimentalrig
in relation to its dimensions and construction accuracy and the second one concerned
the validation and selection of mounting pads in order to isolate the experimental-rig from
external stimulations and the calculation of their mechanical properties. The four
remaining experimental studies were concerned with investigation and validation of
advanced signal processing methodologies for their ability to detect external stimulations
and to detect faults in early stage in rolling- element bearings. At last an industrial case
study was conducted in order to validate the method in real working environment. | en |
dc.format | application/pdf | |
dc.language | sr | |
dc.publisher | Универзитет у Крагујевцу, Факултет инжењерских наука | sr |
dc.relation | info:eu-repo/grantAgreement/EC/FP7/289837/EU// | |
dc.rights | openAccess | en |
dc.rights.uri | https://creativecommons.org/licenses/by-nc-nd/4.0/ | |
dc.source | Универзитет у Крагујевцу | sr |
dc.subject | signal processing | en |
dc.subject | CEEMDAN | en |
dc.subject | ZAMD | en |
dc.subject | bearings | en |
dc.subject | experimental-rig | en |
dc.subject | maintenance | en |
dc.subject | diagnostic methodologies | en |
dc.subject | time-frequency analysis | en |
dc.title | Detekcija otkaza kotrljajnih ležajeva primenom naprednih vremensko-frekvencijskih metoda analize signala vibracija | sr |
dc.type | doctoralThesis | en |
dc.rights.license | BY-NC-ND | |
dc.identifier.fulltext | https://nardus.mpn.gov.rs/bitstream/id/48251/Hristos_Tsiafis_FIN.pdf | |
dc.identifier.fulltext | http://nardus.mpn.gov.rs/bitstream/id/48250/Disertacija.pdf | |
dc.identifier.fulltext | http://nardus.mpn.gov.rs/bitstream/id/48251/Hristos_Tsiafis_FIN.pdf | |
dc.identifier.fulltext | https://nardus.mpn.gov.rs/bitstream/id/48250/Disertacija.pdf | |
dc.identifier.rcub | https://hdl.handle.net/21.15107/rcub_nardus_10940 | |