ROLE OF LARGER INITIAL CURVATURES AND OF LOCAL SHEET BUCKLING IN THE INTERACTION OF SHEAR LAG WITH BUCKLING IN LONGITUDINALLY STIFFENED COMPRESSION FLANGES.

The paper presents the main results of a continuation to the research described by P. Jetteur et al and dealing with the interaction of shear lag with plate buckling that is frequently encountered in longitudinally stiffened compression flanges of steel box girder bridges. The authors study the interaction of shear lag with global flange buckling for amplitudes, f//o, of the initial 'dishing' larger than those studied by Jetteur et al. The effect of larger initial imperfections is analyzed in the context of three definitions of the ultimate limit state, viz. (i) a definition assuming a high level of plasticity in the flange, (ii) that assuming a lower level of plasticity in the flange and (iii) a quasi-elastic definition of the ultimate limit state. The results are presented graphically.