Channel frames with semi-rigid joints

The analysis and tests of cold-formed thin-walled channel frames including nonlinear flexible or semi-rigid connection behaviour is presented. The semi-rigid connection behaviour is modelled using a mathematical approximation of the connection flexibility or moment–rotation relationship. Local instability in the form of local buckling of members is included in the analysis. The full response of the frame, up to the collapse load, can be predicted. Experimental investigation was carried out on a series of simple double storey symmetrical frames with the purpose of verifying the accuracy and validity of the analysis. Agreement between the theoretical and experimental results is acceptable. The investigation also shows that effect connection thickness on the strength of thin-walled frames is less significant compared to that of the members thickness and lip size. The findings also provide further insight into the study of structures, where interaction between flexible connections and phenomenon associated with thin-walled members are present.