Anforderungen an Stahl- und Verbundknoten bei Stützenausfall in einem Rahmentragwerk

Local failure in a structure (e.g. sudden column loss due to impact or explosion) could lead to progressive collapse propagation of the global structural system resulting in a total collapse. To avoid progressive collapse initiated by local damage a redistribution of force from the damaged part of the structure has to be enabled by alternate load path. Activation of alternate load paths by change of the bearing mechanism from pure bending state to more or less pure membrane state is a measure but only possible by allowing large global deformations resulting in high de-formation requirements for the joints.
In the frame of a European RFCS research project ductile joint solution have been developed to improve the robustness as characteristic of the structure.
Main focus for the joint design was given to obtain the required deformation capacity for acci-dental design situations mainly from the joints and cause at the same time only less additional material and fabrication costs for the joints.
As a result deformable and partial-strength joint solution has been chosen. Objective within the project was to determine requirements of the joints concerning deformation capacity as well as M-N-resistance to enable the activation of catenary action for the load case notional column removal.