774 KB50 KB195120262013Bajc, UrškaBratina, SebastjanPlaninc, IgorSaje, Miranštevilka:5letnik:62str. 105-116ISSN:0017-2774COBISSID:6260065URN:URN:NBN:SI:doc-SOUGZAO7slZveza društev gradbenih inženirjev in tehnikov SlovenijeGradbeni vestnikarmiranobetonska palicagradbeni elementinumerični modelirazpokeNelinearna analiza razpokane armiranobetonske natezne palice - primerjava numeričnih metod| Nonlinear analysis of cracked tensile reinforced concrete bar - comparison of numerical methods|This paper presents three numerical models for nonlinear analaysis of cracked tensile reinforced concrete bar. The first two models are based on the discrete crack method. In the first model, which is mostly reported in literature, the ideal crack is considered, while in the second discrete model the phenomenom of aggregate bridging is included. The third numerical model isbased on the smeared crack concept. This model is used to analyse the softening of reinforced concrete bar. Additionally, the crack width and their locations for all presented models are analysed. Furthermore, we analysed tension stiffness and bearing capacity of cracked reinforced concrete bar. Theresults are compared with other numerical models, based both on the discrete and smeared crack concepts. It is found out that the presented numerical model for the analysis of the behaviour of cracked tensile reinforced concrete elements accounting for aggregate bridging is well appropriate for the determination of the element tension stiffness, the crack width and also their locations. The discrete model with ideal cracks is rathergood in the same way, with the exception of the crack width. Because of the design of the model, the smeared crack model is less accurate in determining the cracks width and their locations, yet it is sufficient for thedetermination of the element tension stiffness. The results have also been compared with the values obtained by the related procedure for evaluating the width and the distance between two cracks, as given in European standard Eurocode 2. We may thus conclude that the proposed method is convenient for the evaluation of the crack width and the crack spacing in practical structural design, tooV članku so predstavljeni trije enodimenzionalni numerični modeli za nelinearno analizo razpokane armiranobetonske natezne palice. Prva dva modela sta zasnovana na osnovi diskretne razpoke. Prvi med njima na t. i. modelu idealne razpoke, drugi pa na modelu t. i. povezane razpoke. Zanj je značilno, da sta nerazpokana betonska ovoja palice ob razpoki povezana z armaturno palico in tudi z agregatnimi zrni. Tretji numerični model za analizo razpokane armiranobetonske natezne palice je model razmazane razpoke. Z vsemi tremi numeričnimi modeli so v članku analizirani širina in število razpok ter togost in nosilnost razpokane armiranobetonske natezne palice. Rezultati analize so primerjani z eksperimentalnimi in numeričnimi rezultati podobnih metod iz znanstvene literature. Primerjave rezultatov so pokazale, da je najnatančnejši numerični model s povezano razpoko. Diskretni model z idealno razpoko je praktično enako natančen kot model s povezano razpoko, manj natančen je le za določitev širine razpoke. Najmanj natančen je model razmazane razpoke. Glede na zasnovo modela se z njim dobro določita le togost in nosilnost razpokane armiranobetonske natezne palice. V zaključku je prikazana tudi ocena ustreznosti poenostavljenega računskega postopka za analizo razpok armiranobetonskih konstrukcij skladno z evropskim standardom EC2. Primerjava je pokazala, da se s poenostavljenim postopkom relativno dobro oceni širina razpokeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaZveza društev gradbenih inženirjev in tehnikov Slovenije