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Elastoplastic damage analysis of trusses subjected to cyclic loading

dc.contributor.advisorŠumarac, Dragoslav
dc.contributor.otherŠumarac, Dragoslav
dc.contributor.otherProkić, Aleksandar
dc.contributor.otherSalatić, Ratko
dc.contributor.otherMandić, Rastislav
dc.creatorPerović, Zoran
dc.date.accessioned2017-04-22T09:34:32Z
dc.date.accessioned2019-05-01T01:32:00Z
dc.date.available2017-04-22T09:34:32Z
dc.date.available2019-05-01T01:32:00Z
dc.date.issued2016
dc.identifier.urihttp://eteze.bg.ac.rs/application/showtheses?thesesId=4858
dc.identifier.urihttps://fedorabg.bg.ac.rs/fedora/get/o:15211/bdef:Content/download
dc.identifier.urihttp://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=513734290
dc.identifier.urihttp://nardus.mpn.gov.rs/123456789/7954
dc.identifier.urihttp://grafar.grf.bg.ac.rs/handle/123456789/1689
dc.description.abstractU ovoj doktorskoj disertaciji je razmatrano ponašanje rešetkastih konstrukcija u plastičnojoblasti sa ciljem da se optimizuje numerička analiza ovog problema i da se definiše osnovaza proširivanje odgovarajućeg modela na gredne elemente linijskih nosača. Ovaj problem,pri cikličnom opterećenju, dobija novu dimenziju u pogledu tačnosti rezultata nakonodređenog broja ciklusa, kao i u pogledu numeričke zahtevnosti odgovarajućeg modela.Model materijala zasnovan na Prajzakovom (Preisach) histerezisnom operatoru, određenkao analitički izraz za vezu napon-deformacija, omogućava numerički efektno modeliranjejednoaksijalnog ponašanja materijala. Koristeći ovaj model, u ovoj disertaciji su definisanejednačine u metodi konačnih elemenata za elastoplastičnu analizu rešetkastih nosača pricikličnom opterećenju i na osnovu toga je definisan algoritam za proračun u programskomjeziku c++.Za validaciju rezultata i analizu numeričkih karakteristika proračuna zasnovanog na modelumaterijala koji je korišćen u disertaciji, u numeričkim primerima su poređeni rezultatidobijeni predmetnim modelom sa rezultatima dobijenim koristeći drugi histerezisnioperator (Bouc-Wen) i rezultatima dobijenim koristeći jedan od klasičnih modelaplastičnosti (model generalisane plastičnosti).Geometrijska nelinearnost je uzeta u obzir poznatim metodama i definisana u delunumeričkih primera. Stanje napona u materijalu koji se analizira je jednoaksijalno, a unumeričkim primerima sa grednim elementima je usvojena hipoteza o ravnim presecima.Pored postojećeg (Prajzakovog) modela za elastoplastično ponašanje materijala, u ovojdisertaciji je definisan model oštećenja u materijalu preko dva pristupa. U prvom pristupu,definisani histerezisni operator za elastoplastično ponašanje materijala je modifikovan kakobi mogao da modelira oštećenje u materijalu. U drugom pristupu, u definisani algoritamproračuna metode konačnih elemenata predmetnog modela elastoplastičnosti je uvedenfenomen oštećenja korišćenjem osnovnih principa mehanike kontinuuma sa oštećenjem.Pored toga, predstavljen je model za proračun histerezisnog gubitka energije u rešetkastimkonstrukcijama, zasnovan na predmetnom modelu, kao i osnova za proširenje analize nagredne nosače koristeći numeričku integraciju napona u poprečnom preseku za jednostavneslučajeve savijanja...sr
dc.description.abstractIn this doctoral dissertation, behavior of trusses in plastic domain is investigated in order tooptimize numerical analysis of this problem and to define foundation for extendingproposed model to the analysis of beam elements. New dimension in this problem arise inthe case of the cyclic loading, relating to the accuracy of results after certain number ofcycles and computational effort of corresponding model. Material model based on thePreisach hysteretic operator, determined as analytical expression for stress-strain relation,enables numerically effective modeling of uniaxial material behavior. By using this model,in this dissertation, finite element equations for elastoplastic analysis of trusses subjected tocyclic loading are determined, which lead to definition of algorithm for numerical analysisin c++ programming language.In order to validate results and to analyze numerical performance of calculation based onthe material model used in this dissertation, in numerical examples, results obtained byanalyzed (Preisach) model are compared with results obtained by using other hystereticoperator (Bouc-Wen) and also with results obtained by using one of the classical model ofplasticity (generalized plasticity model).Geometric nonlinearity is taken into account by well established methods, and it wasdefined in several numerical examples. Stress state in analyzed material is uniaxial, and innumerical examples with beam elements, the assumption of engineering beam theory isadopted (cross section is perpendicular to a bending line).Besides existing (Preisach) model for elastoplastic material behavior, in this dissertationdamage model in material is defined through two approaches. In the first approach,proposed hysteretic operator for elastoplastic behavior is modified, so that it would have thepossibility to model the damage in material. In the second approach, in proposed finiteelement algorithm for elastoplastic analysis, phenomenon of damage is introduced by usingthe basic principles of continuum damage mechanics.In addition, model for calculation of hysteretic energy loss in truss structures, based on theconsidered model, is presented, and finally, the foundation for extending the correspondinganalysis on beam elements, by using numerical integration of normal stress in cross section,for simple cases of loading, is proposed...en
dc.formatapplication/pdf
dc.languagesr
dc.publisherУниверзитет у Београду, Грађевински факултетsr
dc.rightsopenAccess
dc.sourceУниверзитет у Београдуsr
dc.subjectrešetkasr
dc.subjecttrussen
dc.subjectcyclic plasticityen
dc.subjecthysteresisen
dc.subjectdamageen
dc.subjectoperatoren
dc.subjectnonlinear analysisen
dc.subjectnumerical efficiencyen
dc.subjectciklična plastičnostsr
dc.subjecthisterezissr
dc.subjectoštećenjesr
dc.subjectoperatorsr
dc.subjectnelinearna analizasr
dc.subjectnumerička efikasnostsr
dc.titleElastoplastična analiza rešetkastih nosača sa oštećenjem pri cikličnom opterećenjusr
dc.title.alternativeElastoplastic damage analysis of trusses subjected to cyclic loadingen
dc.typedoctoralThesisen
dc.rights.licenseBY-NC-ND
dc.identifier.fulltexthttp://grafar.grf.bg.ac.rs//bitstream/id/6432/1687-teza.pdf
dc.identifier.fulltexthttp://grafar.grf.bg.ac.rs/bitstream/id/4343/1687.pdf
dc.type.versionpublishedVersion


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