Naslov
Modelling of steel creep at high temperatures using implicit creep model

Autori
Torić, Neno ; Harapin, Alen ; Boko, Ivica ; Peroš, Bernardin

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
6th International Conference on Advanced Computational Engineering and Experimenting (ACEX2012) : Abstract book / Öchsner, Andreas - Ilhavo : Ironix Conference Management, 2012, 117-118

Skup
International Conference on Advanced Computational Engineering and Experimenting (6 ; 2012)

Mjesto i datum
Istanbul, Turska, 01.07.2012. - 04.07.2012

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
fire; heat transfer; finite element; steel; creep strains

Sažetak
Behaviour of steel structures at high temperatures is greatly influenced by the level of creep strains that occur after reaching the temperature above one third of the melting point of steel. For structural carbon steel, this occurs after reaching the structure temperature above 400°C. Generally, for the simply supported elements with no axial restraints, creep strain affects the vertical deformability, while in the elements which have axial restraints creep strain induces development of additional inner forces. Consequently, creep strains have significant effect on the load bearing capacity of steel structures exposed to fire. The paper presents the numerical procedure for modelling the behaviour of steel creep at high temperatures using implicit creep model. Calculated creep strains are used to modify the material stress-strain curves, thus implicitly taking into account the effect of developed creep strain. Stress-strain curves are modified by stretching the initial temperature dependent stress-strain curves using the calculated value of creep strain, depending on the level of temperature and stress that the section of structure is being exposed to during fire. Implicit numerical procedure has been implemented in a previously developed computer programme for predicting the behaviour of structures under fire. In order to test the validity of implicit creep model, an inhouse fire experiment was performed. Two simply supported steel beam elements were loaded and exposed to high temperatures. Surface temperatures of the element were measured in 12 points and midspan deflections were recorded during the experiment. Results of the experiment have shown good agreement with the model predictions indicating the validity of the developed implicit numerical procedure.

Izvorni jezik
Engleski

Znanstvena područja
Građevinarstvo

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