Außergewöhnliche Bemessungssituationen nach DIN EN 1991-1-7 - Effektive Anwendung und Bemessungsstrategien für Stahl- und Verbundrahmentragwerke

Exceptional design situations according to DIN EN 1991-1-7 - Effective application and design strategies for steel and composite buildings.

A local damage within a frame structure (e. g. column loss) may lead to a failure of the global structure and therefore to a collapse of the building. To avoid such a global failure through local damage it is necessary to enable a redistribution of loadings within the structure. This means that the development of alternate load paths should be enabled in order to enhance the structural robustness. Such a redistribution of loadings from a pure bending to a bending-membrane-loading causes under certain circumstances large deflections leading to big deformations of the joints.
In the frame of a German research project "Exceptional design situations according to DIN EN 1991-1-7 - Effective application and design strategies for steel and composite buildings" four tests on composite joints under simultaneous and successive M-N-loading have been performed. The different behaviour of sagging and hogging moment at the joints was investigated and the different load bearing behaviour as well as deformation behaviour of the concrete plate was considered. The influences of the dynamic effects, as they occur in the case of an impact, on the deformation behaviour of the joints are worked out within four further tests on composite joints under high speed loading in the frame of a European research project "RobustImpact".
As the required rotation capacity can only be determined in real frame structures additionally two tests on composite frames have been performed with the aim to absorb an additional vertical loading through large deformations activating the catenary effect in the composite frame without receiving a premature failure.