Primerjava modelov za numerično analizo armiranobetonskih konstrukcij

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Language:	Slovenian
Year of publishing:	2009
Source:	Ljubljana
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FGG - Faculty of Civil and Geodetic Engineering
Publisher:	[J. Lopatič]
UDC:	519.61/.64:624.012.45:624.073(043.2)
COBISS:	4577633
Views:	1825
Downloads:	602
Average score:	0 (0 votes)
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Secondary language:	English
Secondary title:	Comparison of models for numerical analysis of reinforced concrete structures
Secondary abstract:	This work is related to preparation of a suitable numerical model for linear elastic analysis of reinforced concrete structures by using the finite element method. Namely, the internal forces, computed by the finite element method, considerably depend on the chosen numerical model. It is well known that they depend on the “quality” of the finite element used (which is out of the influence of the user of the commercial finite element based computer code) and on the density of the finite element mesh. However, it is not so widely known that other factors may have considerable influence on computed internal forces, for example modelling of supports. It is shown in this work by several examples that “classical” support models in plate and wall analysis can lead to unbounded internal forces at support regions with refinements of the mesh. It is also shown that a remedy to this problem is usage of real stiffness of the supportive structure in the numerical model. Several structural examples are computed by different numerical models. The results are compared between the models and with the results of simplified analyses found in the literature and codes.
Secondary keywords:	graduation thesis;civil engineering;numerical model;area structure;plate;beam;
File type:	application/pdf
Type (COBISS):	Undergraduate thesis
Thesis comment:	Univ. Ljubljana, Fakulteta za gradbeništvo in geodezijo
Pages:	X, 76 str., pril.
Type (ePrints):	thesis
Title (ePrints):	Comparison of models for numerical analysis of reinforced concrete structures
Keywords (ePrints):	numerični model;ploskovna konstrukcija;plošča;nosilec
Keywords (ePrints, secondary language):	numerical model;area structure;plate;beam
Abstract (ePrints):	Diplomska naloga se nanaša na pripravo ustreznega modela za linearno elastično analizo armiranobetonskih ploskovnih konstrukcij po metodi končnih elementov. Notranje sile, ki jih izračunamo s programom po metodi končnih elementov, so namreč precej odvisne od izbranega numeričnega modela. Dobro je znano, da na izračunane notranje sile vplivata “kakovost” izbranega končnega elementa (na kar uporabnik komercialnega računalniškega programa navadno ne more dosti vplivati) ter gostota mreže končnih elementov. Manj pa je znano, da na izračunane notranje sile lahko znatno vplivajo tudi drugi dejavniki, kot so npr. način modeliranje podpor. V nalogi z več primeri pokažem, da se pri “klasičnem” načinu modeliranja podpor pri analizi plošč in sten notranje sile nad podporami neomejeno večajo z zgoščevanjem mreže. Nadalje pokažem, da se ta problem lahko reši tako, da se v numeričnem modelu upošteva dejanska togost podporne konstrukcije (sten ali stebrov). Poleg tega pokažem več primerov numeričnih analiz plošč, sten in nosilcev z različnimi modeli, ki se med seboj razlikujejo predvsem v obravnavi podpor. Dobljene rezultate primerjam med seboj in z rezultati poenostavljenih analiz iz priročnikov in standardov, ki so prilagojeni “peš” računom.
Abstract (ePrints, secondary language):	This work is related to preparation of a suitable numerical model for linear elastic analysis of reinforced concrete structures by using the finite element method. Namely, the internal forces, computed by the finite element method, considerably depend on the chosen numerical model. It is well known that they depend on the “quality” of the finite element used (which is out of the influence of the user of the commercial finite element based computer code) and on the density of the finite element mesh. However, it is not so widely known that other factors may have considerable influence on computed internal forces, for example modelling of supports. It is shown in this work by several examples that “classical” support models in plate and wall analysis can lead to unbounded internal forces at support regions with refinements of the mesh. It is also shown that a remedy to this problem is usage of real stiffness of the supportive structure in the numerical model. Several structural examples are computed by different numerical models. The results are compared between the models and with the results of simplified analyses found in the literature and codes.
Keywords (ePrints, secondary language):	numerical model;area structure;plate;beam
ID:	8309911