Estudo de almas de vigas de aço enrijecidas longitudinalmente

Abstract

Verification of slender cross sections is complex and can be performed through numerical simulations using the Finite Element Method. However, the common practice among structural designer is the use of technical standards simplifications, which directly affects the weight of the steel structure. Therefore, it is considered necessary to evaluate the analytical methods employed by the standards used in the verification of slender sections of steel commonly applied in bridges, viaducts or industrial buildings structures. This work presents a comparative study of the analytical methods proposed by European standards to check slender sections: reduced stress method (MTR) according to Germanrecommendation DASt Richtlinie 012 (SCHEER et al., 1979) and EN 1993-1-5:2006 and effective width method (MLE) according to EN 1993-1-5: 2006. The study focuses on the stiffened webs of slender steel I girders, subjected to longitudinal normal stresses and shear. Eight stiffened webs are studied, with one or two longitudinal stiffeners in the compressed region. In order to perform the verification of the case studies covering the MLE and MTR methods spread sheets developed in computer programs Mathcad 2001 Professional and Microsoft Office Excel, and the computer program EBPlate 2:01 (2007), were used. The results are compared with each other, for each case of stiffened webs verified and every standard used. The differences between the analytical methods with its advantages and disadvantages are evaluated. Significant differences are observed between the values of the two methods applied. The thicknesses obtained for the webs studied as MTR German recommendation DASt Richtlinie 012 (SCHEER et al., 1979) are considerably higher than those obtained according to the MTR of EN 1993-1-5:2006, which are bigger than those obtained by MLE.