Both heads of beams of steel frames that transfer momentum must be held in certain intervals. The aim here is to support the beam laterally to prevent buckling and to allow the formation of plastic joints in areas whose capacity is preserved. In this way, the entire capacity of the beam is used.
In TBDY 2018 Annex 9B, the lengths of the plastic joints and the areas expected to occur are defined. These sections, which are called the zone of protected capacity, are defined as the zone that will absorb energy under reversible effects such as earthquakes. Therefore, in order to benefit from the capacity of these regions, the beams must be supported laterally.
In a way, with this control, the secondary beam placement and structural stability are determined.
In accordance with the condition given in Equation 9.2, it should be supported against lateral buckling with lateral support elements.
In steel carrier systems where reinforced concrete floors work as a composite with steel beams, this condition is not required for the headers of the beams connected to the reinforced concrete floor.
ideCAD Static applies and reports this control automatically.
Icons
i y : Radius of inertia with respect to the weak axis of the beam cross-section
E: Modulus of elasticity of structural steel
F y : Characteristic yield stress of structural steel
L b : Non-affectionate size