Flange Buckling Behavior of Stainless Steel Girders with Trapezoidally Corrugated Webs - A parametric numerical study

Examensarbete för masterexamen
Achour, Alaa
Mlli, Ziad
The replacement of a flat web with a corrugated one in steel girders is a way of increasing the shear buckling capacity, without the need of additional vertical stiffen ers. But, except for that, the corrugation of the web changes the bending behavior, more specifically the normal stress buckling behavior of the flange plate. Numerous investigations have been conducted on this subject for trapezoidally corrugated web I-girders in carbon steel, with the one by Jáger et al. being the most extensive one, comprising both experimental and numerical investigations. But, no design models for trapezoidally corrugated web I-girders in stainless steel are available. The current study aims at investigating the normal stress flange buckling of trapezoidally corrugated web I-girders in stainless steel in terms of the elastic buck ling coefficient and required reduction factor. The analyses are performed in theanalysis software ABAQUS. The results of the parametric numerical studies arecompared to the existing models for carbon steel girders suggested by Eurocode 3(EN1993-1-5), the DASt Richtlinie 015 and Jáger et al. In case these prove to be inaccurate, a design model is developed. The results of the comparisons generally showed that the method of approxi mating the buckling coefficient and required reduction factor developed by Jáger et al. is an improvement compared to Eurocode 3. The DASt Richtlinie 015 leads to the most inaccurate approximations of the reduction factor. The suggested buckling curve of Eurocode 3, originally developed for flat web girders, has a too high relative slenderness limit of λ¯p = 0, 748, which, according to the obtained results, should be λ¯p = 0, 4. This is the main reason behind the Eurocode model resulting in over-estimations for almost all analysed girders. The improvement in the accuracy of estimations demonstrated by the design models of Jáger et al. are concluded to be the result of considering several parameters related to corrugation geometry. This insight is applied in the development of a new model to approximate the buckling coefficient, consequently used as input parameter in the expression of the relative slenderness ratio λ¯p. A buckling curve is then designedas a function of this parameter.
corrugated web, stainless steel, Duplex, normal stress, flange buckling, parametric study, numerical study.
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