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Faktori intenziteta napona višestrukih prslina na duraluminijumskim panelima

dc.contributor.advisorGrbović, Aleksandar
dc.contributor.otherSedmak, Aleksandar
dc.contributor.otherPetrašinović, Danilo
dc.contributor.otherMilković, Dragan
dc.contributor.otherKastratović, Gordana M.
dc.creatorAldarwish, Mustafa Mohamed Ali.
dc.date.accessioned2020-01-27T12:20:54Z
dc.date.available2020-01-27T12:20:54Z
dc.date.available2020-07-03T08:42:54Z
dc.date.issued2018-06-06
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=7085
dc.identifier.urihttps://nardus.mpn.gov.rs/handle/123456789/11764
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:20724/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=514935715
dc.description.abstractThe aim of this thesis was to establish and demonstrate significant capacity and performances of extended finite element method (XFEM) to calculate stress intensity factors (SIFs) histories versus crack length for problems involving multiple, interacting cracks resulting from multiple site damage (MSD). The thesis includes two deferent types of a typical aero structural configuration were analyzed: the first was unstiffened flat panel made of aluminum Al 2024-T3, containing 11 holes, each of which is a site for crack growth. Analyzed model makes a unique 3D configuration with 22 cracks, propagating at the same time; the applied stresses were equal to 50,100 and 200 MPa. The computations were carried out in Morfeo/Crack for Abaqus software which relies on the implementation of XFEM. The accuracy of these computations was verified through FRANC2D/L software and superposition based approximate method. The conducted analysis showed that XFEM is efficient tool for the simulation of crack propagation even in the case of 3D configurations with MSD, and that the obtained solutions can be used for the prediction of SIFs in analyzed MSD configuration with acceptable accuracy. The second type of aero structural configuration which analyzed in this research using XFEM as following:- - The first model was unstiffened curved panel with 3 rivet holes containing 6 cracks propagating at the same time; the applied average pressure was (0.054 MPa). - The second model was unstiffened curved panel with 5 rivet holes containing 10 cracks propagating at the same time; the applied pressure was (0.054 MPa). - The third model was unstiffened curved panel with 7 rivet holes containing 14 cracks propagating at the same time; the applied average pressure was (0.054 MPa). - The forth model was unstiffened curved panel with 11 rivet holes containing 22 cracks propagating at the same time; the applied average pressure was (0.054 MPa). STRESS INTENSITY FACTORS EVALUTION AT TIPS OF MULTIPLE SITE CRACKS IN 2024-T3 ALUMINUM PANELS v - All curved panels simulations study includes the relationship between crack length and its corresponding SIFs values for every crack propagation step, Also, the study includes the effect of change fuselage diameters from 1.6m, 2.4 m, 3.2 m to 4 m on every crack of the whole models and its SIF values. - Also, the computations were carried out in Morfeo/Crack for Abaqus software which relies on the implementation of XFEM. The conducted analysis showed that XFEM is efficient tool for the simulation of crack propagation even in the case of 3D configurations with MSD, and that the obtained solutions can be used for the prediction of SIFs in analyzed MSD configuration with acceptable accuracy. - Additionally, the research includes study and comparisons of SIF values for two flat and curved panels which had the same dimensions and number of the cracks (22 cracks); and study the effect of truss by adding frames on the curved model with 22 cracks, the results showed a high decreasing in SIF values. - Finally, the research includes some SIFs calculations using standard model. The calculations are done using the empirical equations and NASGROW software. The comparisons showed excellent and accurate results using both methods.en
dc.description.abstractOsnovni cilj ove teze jeste demonstracija mogućnosti i značaja proširene metode konačnih elemenata (PMKE) u izračunavanju vrednosti faktora intenziteta napona (FIN) u slučajevima višestrukih međusobno uticajnih prslina nastalih kao posledica pojave višestrukih oštećenja na strukturi (VOS). Teza obuhvata analizu dve tipične aero-strukturne konfiguracije. Prva od njih je neojačana ravna ploča od duraluminijuma 2024-T3 sa 11 otvora za zakivke, od kojih svaki predstavlja mesto gde je rast prsline vrlo verovatan. Analizirani model čini jedinstvena 3D konfiguracija sa 22 prsline koje rastu istovremeno. Primenjeni naponi na krajevima ploče iznosili su 50, 100 i 200 MPa. Proračuni su sprovedeni u programu Morfeo/Crack for Abaqus koji se oslanja na implementaciju PMKE-a. Tačnost dobijenih rezultata verifikovana je pomoću softvera FRANC2D/L i približne metode zasnovane na principu superpozicije. Izvedena analiza pokazala je da je PMKE efikasan alat za simulaciju širenja prslina u slučaju ravnih 3D konfiguracija sa VOS i da se dobijena rešenja mogu koristiti za predviđanje FIN-a u analiziranoj VOS konfiguraciji sa prihvatljivom tačnošću. Druga aero-strukturna konfiguracija koja je analizirana korišćenjem PMKE u okviru ovog istraživanja sastojala se iz nekoliko modela VOS-a: - Prvi model bio je neojačani zakrivljeni panel sa 3 otvora za zakivke i ukupno 6 prslina koje se istovremeno šire iz otvora; primenjeni diferencijalni pritisak iznosio je 0,054 MPa. - Drugi model bio je neojačani zakrivljeni panel sa 5 otvora za zakivke i ukupno 10 prslina koje se istovremeno šire iz otvora; primenjeni diferencijalni pritisak iznosio je 0,054 Mpa. - Treći model bio je neojačani zakrivljeni panel sa 7 otvora za zakivke i ukupno 14 prslina koje se istovremeno šire iz otvora; primenjeni diferencijalni pritisak iznosio je 0,054 MPa. STRESS INTENSITY FACTORS EVALUTION AT TIPS OF MULTIPLE SITE CRACKS IN 2024-T3 ALUMINUM PANELS vii - Četvrti model bio je neojačani zakrivljeni panel sa 11 otvora za zakivke i ukupno 22 prsline koje se istovremeno šire iz otvora; primenjeni diferencijalni pritisak iznosio je 0,054 Mpa. Sve simulacija širenja višestrukih prslina na zakrivljenim pločama uključuju vezu između dužine prslina i odgovarajućih vrednosti FIN-a za svaki korak širenja prsline. Takođe, u istraživanju je u obzir uzet i efekat promene prečnika krivine panela, pa su vrednosti FIN-a računate za sva četiri modela u slučajevima zakrivljenosti od 1,6 m, 2,4 m, 3,2 m i 4 m. I u ovim slučajevima proračuni su vršeni u programu Morfeo/Crack for Abaqus zasnovan na PMKE. Analiza dobijenih rezultata pokazala je da je PMKE efikasan alat za simulaciju širenja prslina u slučaju 3D konfiguracija sa VOS i da se dobijena rešenja mogu koristiti za predviđanje zamornog veka sa prihvatljivom tačnošću. Pored toga, istraživanje predstavljeno u ovoj tezi uključilo je i proučavanje i upoređivanje vrednosti FIN-a u slučaju ravnog i zakrivljenog panela istih dimenzija i broja prslina (dvadeset i dve), kao i proučavanje efekta ojačanja panela dodavanjem okvira na zakrivljenom modelu sa 22 prsline. Rezultati su pokazali značajno smanjenje vrednosti FIN-a na ojačanom panelu. Najzad, istraživanje je obuhvatilo i određivanje FIN-a korišćenjem standardnih modela u svrhu evaluacije rezultata dobijenih pomoću PMKE. Proračuni su vršeni korišćenjem empirijskih jednačina i NASGRO softvera. Poređenje rezultata je pokazalo vrlo dobro poklapanje vrednosti dobijenih korišćenjem različitih metoda.sr
dc.formatapplication/pdf
dc.languageen
dc.publisherУниверзитет у Београду, Машински факултетsr
dc.rightsopenAccessen
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.sourceУниверзитет у Београдуsr
dc.subjectfatigue crack growthsr
dc.subjectrast zamornih prslinaen
dc.subjectmulti site damage (MSD)sr
dc.subjectextended Finite Element Method (XFEM)sr
dc.subjectNASGROsr
dc.subjectFRANC2D/Lsr
dc.subjectLEFM - linear-elastic fracture mechanicssr
dc.subjectstress intensity factor- KIsr
dc.subjectcurved and flat panelssr
dc.subjectvišestruko oštećene strukture (VOS)en
dc.subjectproširena metoda konačnih elemenata (PMKE)en
dc.subjectNASGROen
dc.subjectFRANC2D/Len
dc.subjectlinearna elastična mehanika lomaen
dc.subjectfaktor intenziteta napona (FIN)en
dc.subjectzakrivljeni i ravni duraluminijumski panelien
dc.titleStress intensity factors evaluation at tips of multiple site cracks in 2024-T3 aluminum panelsen
dc.title.alternativeFaktori intenziteta napona višestrukih prslina na duraluminijumskim panelimasr
dc.typedoctoralThesisen
dc.rights.licenseBY
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/7504/Disertacija.pdf
dc.identifier.fulltexthttp://nardus.mpn.gov.rs/bitstream/id/7505/IzvestajKomisije21597.pdf
dc.identifier.fulltexthttps://nardus.mpn.gov.rs/bitstream/id/7504/Disertacija.pdf
dc.identifier.fulltexthttps://nardus.mpn.gov.rs/bitstream/id/7505/IzvestajKomisije21597.pdf
dc.identifier.rcubhttps://hdl.handle.net/21.15107/rcub_nardus_11764


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