Steel Buildings in Europe

Part 10: Technical Software Specification for Composite Beams 10 - 30  f is the angle between concrete compression struts and tension chords. This can be defined by the National Annex. Here it is proposed to take:  f = 45° v Ed is the longitudinal shear action defined by: h x v F Δ Δ f d Ed   F d is the variation of the compression axial force in the slab along a distance  x between two given sections. The calculation is performed along a segment close to each end of the beam. Then:  F d = ( N c – 0)/2 = N c /2 N c is calculated according to 6.3.7. For uniform distributed loads, the calculation is performed between the section located at mid span and the support (  x = L /2). For a beam with point loads, the calculation has to be performed along a segment between the section under the point load and the closest support.  F d 1 2  x Figure 6.2 Determination of  F d 6.4.3 Concrete strength in the compression struts The criterion for the concrete strength of the compression struts is calculated by the following expression: f f cd Ed Vh cos sin     f v  This criterion is calculated for each segment considered in 6.4.2 and then the maximum value is derived.