magistrsko delo na študijskem programu 2. stopnje UM
Mitja Papinutti (Author), Janja Kramer Stajnko (Mentor), Andrej Štrukelj (Co-mentor)

Abstract

Veter je bil v preteklosti že vzrok za številne porušitve gradbenih konstrukcij in mostov, zato je poznavanje in analiza vetrnih obtežb v fazi projektiranja ključnega pomena. Pri večjih projektih, kot so daljši mostovi, zaenkrat še ne obstajajo standardi, ki bi določali, kako izračunati vplive vetra na mostno konstrukcijo, tako mora vsak inženir prevzeti odgovornost in izbrati pravilen pristop k problemu. Klasične študije obtežbe vetrov na mostove se opirajo na preizkuse v vetrovnikih, ki jih je v zadnjem času možno nadomeščati z računalniškimi simulacijami. V magistrskem delu so predstavljena matematična orodja skupaj s programi za celovito računalniško analizo vetrnih obtežb na mostne konstrukcije, pri čemer ni potrebno uporabljati vetrovnika. Aeroelastična nestabilnost, kot je omahovanje, je rušilno gibanje mostu v laminarnem vetru. Za ustrezno varnost mostu je potrebno oceniti, pri kateri hitrosti vetra nastopi nestabilnost in kakšna je povratna doba tega pojava. Aeroelastične analize in analize turbulentnega vetra so narejene s sestavljanjem kompleksnega tridimenzionalnega dinamičnega modela konstrukcije in z enostavnim preizkusom segmenta iz vetrovnika. Klasična matematična teorija je grajena na bazi preizkusov v vetrovnikih in je v celoti razvita s frekvenčno metodo. Odzivi mostu v vetru morajo biti poznani za vsak projekt posebej, saj se lahko le na podlagi teh informacij oceni potreba po omejevanju vibracij oziroma po vgraditvi dušilcev vibracij. Glavni cilj magistrskega dela je izračun kritičnih hitrosti vetra, ki povzroči porušitev mostov v času gradnje oziroma že zgrajenih mostov z različnimi pristopi.

Keywords

vetrna obtežba;interakcija tekočine in objekta;aeroelastika mostov;računalniška dinamika tekočin;odvodi omahovanja;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FGPA - Faculty of Civil Engineering, Transportation Engineering and Architecture
Publisher: [M. Papinutti]
UDC: 624.5.042.42(043.2)
COBISS: 17545494 Link will open in a new window
Views: 2040
Downloads: 267
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Other data

Secondary language: English
Secondary title: WIND LOADINGS ON SUSPENSION AND CABLE-STAYED BRIDGES
Secondary abstract: In bridge planning phase it is important to know impacts of wind, which caused many collapses of structures in the past. Current standards do not cover wind loading on bridges longer than 200 meters and it depends on individual engineer which approach will be chosen. All studies are based on wind tunnel experiments, which are recently common replaced and compared with computational simulations. In the present work mathematical models together with commercial programs for computational analysis are presented, where the experiments in the wind tunnels are not necessary. Many benefits are highlighted in favour of fully computational approaches compared with wind tunnel tests. Aeroelastic instability like flutter is destructive vibration in laminar wind flow. For appropriate safety of the bridge critical wind speed must be calculated and return period of phenomena must be known. Aeroelastic study is done with hybrid approach, which uses combination of complex three dimensional structural modal and simple wind tunnel tests on board deck. Mathematical model is based on the frequency domain method, where the parametes from the wind tunnel experiments are replaced with Computational Fluid Dynamics (CFD). Wind response of the bridge should be known for each project respectively, because information for limit vibrations and prevention of collapse is delivered. The main objective of Master`s thesis is to present correct approach to address aeroelastic problem and to deliver the suitable mathematical models and programs. The main goal is to calculate flutter speed with different approaches for the bridges under construction and fully erected bridges.
Secondary keywords: wind load;fluid structure interaction;bridge aeroelasticity;computational fluid dynamics;flutter derivatives;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za gradbeništvo
Pages: XI, 125 str.
ID: 8726052