[en] Due to the demand for sustainable constructions, composite structures have become more important and lead to slim and economic solutions with a low structural self-weight. EN 1994-1-1 differentiate four different cross-section classes for the determination of moment resistance. For the plastic design of the moment resistance it is assumed, that each cross-sectional fibre can plastify without any limitation of the strains. For standard composite beams in case of sagging moments and a high-lying plastic neutral axis, plastic design and strain-limited design give similar results. In the case of sections with a large compression zone height xpl and limited rotation capacity, a concrete failure in the compression zone can occur before the plastic moment resistance Mpl,Rd, is reached. The strain limit design becomes decisive. This paper points out the impact of the concrete part on the design of composite beams. A parametric study comparing plastic and strain limited moment resistance of a considerable variety of cross-sections has been carried out to develop the beam design methods considering high compression zone height of next generation of Eurocodes.
[University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit >]
