Member strength checks (Composite beams: EC4 Eurocode)
Member strength checks are performed at the point of maximum moment, the point of maximum shear, the position of application of each point load, and at all other “points of interest” along the beam.
Shear capacity
Shear capacity is determined in accordance with EC3 clause 6.2.6 (1). Where the applied shear force exceeds 50% of the capacity of the section, the high shear condition applies to the bending moment capacity checks (see below).
The following points should be noted:
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No account is taken of fastener holes in the flange or web - see EC3 6.2.6 (7)
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Shear is not combined with torsion and thus the resistance is not reduced as per EC3 6.2.6(8)
Web Shear buckling
See: Steel Beam Design to EC3 - Web shear buckling
Bending moment capacity
For low shear this is calculated to EC3 Equation 6.13. In the high shear case Equation 6.29 is used. Where the high shear condition applies, the moment capacity calculation is made less complicated by conservatively adopting a simplified shear area.