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# 2.1.3 Shear Forces Between Web and Flanges of T-Beams

### Shear Forces Between Web and Flanges of T-Beams

The longitudinal shear stress vEd,f at the junction between flange and web is determined by the longitudinal force difference Δ Fd,f in the flange's governing part according to EN 1992-1-1, clause 6.2.4 (3), equation (6.20).

where

 hf flange thickness at junction Δxf considered length ΔFd,f longitudinal force difference in flange over length Δx

The maximum value that may be assumed for the length Δxf is half the distance between the maximum and the zero point of moments. Where concentrated loads are applied, the distance between the concentrated loads should not be exceeded.

The determination of Δ Fd,f is done optionally with a control available in the module details according to two different methods that are described below.

1. Simplified method via inner lever arm z = 0.9d without considering Mz,Ed

 for compression flanges for tension flanges

where

 zs distance between centroid of cross-section and tension reinforcement z lever arm of internal forces 0.9 d beff,i width of adjacent flange (compression flange) or width of reinforcement distribution in adjacent flange (tension flange) considering the Distribute reinforcement evenly over complete slab width option (see Figure 3.30) beff flange width Asa reinforcement exposed in connected tension flange As total area of tension reinforcement

2. Calculation of Fd from general stress integration in partial areas of cross-section

The required tension flange reinforcement due to shear forces per unit length asf may be determined according to equation (6.21).

where

 1.0 ≤ cot θf ≤ 2.0 inclination of concrete compression strut for compression flanges 1.0 ≤ cot θf ≤ 1.25 inclination of concrete compression strut for tension flanges fyd design yield strength of reinforcement

At the same time, the compression struts in the flange must be prevented from failing, which is ensured if the following requirement is met:

Equation 2.6 EN 1992-1-1, Eq. (6.22)

where

 fcd design value of concrete strength ν1 reduction factor for concrete strength in case of shear cracks