Vereinfachtes Bemessungsverfahren geschraubter teiltragfähiger Stahl- und Verbundknoten

Simplified design method for bolted partial-strength joints.

The component method in DIN EN 1993-1-8 is a tool for designing joints which is at the moment not adequately utilized in practice due among others to the complex design procedure. The method however offers the possibility to design joints for high resistance and ductility in a targeted way. But for ductile joints the method lacks more detailed ductility criteria and does not consider all carrying effects.
The decisive factor for the ductility and bearing capacity of the connection is the interaction between endplate capacity (or column flange capacity) and bolts capacity. The endplate and the column flange have to sustain a high deformation capacity to allow large joint rotations and the bolts should not fail prematurely. By large deformations the endplate does not only develop pure bending, but also membrane effects. The load capacity of the endplate is therefore higher than resulting from pure bending load effect. But the deformations of the endplate also cause additional bending and shearing of the bolts.
The simplified design method for bolted joints presented here determines the moment resistance of the joint based on the tensile capacity of the bolts modified by a connection correction factor and the inner lever arm. The connection correction factor considers all unfavorable effects on the pure tensile capacity of the bolts which might occur at the joint. Furthermore, an application range has been defined for the method to control the relevant components at the joint. To ensure sufficient ductility of the joint additional ductility criteria have been developed. The new design method can now be used to dimension full and partial-strength joints with high resistance and ductility in only a few calculation steps.