Local-distortional interaction in cold-formed steel lipped channel beams: Experimental investigation

This paper reports an experimental investigation on the behaviour and strength of cold-formed high-strength steel (G450-G500) lipped channel beams susceptible to local-distortional interaction. The experimental campaign comprised 36 tests involving simply supported beams bent about the major axis, exhibiting various ratios between their distortional and local critical buckling moments (from 1.09 to 1.46) and acted by either uniform (20 tests) or non-uniform (trapezoidal: 16 tests) bending diagrams. The results presented and discussed consist of equilibrium paths, photos providing the evolution of the beam deformed configurations and failure moments. The paper also includes a few remarks on the design, using the Direct Strength Method, of the beams under consideration.