Lateral torsional instability of single channels restrained by angle cleats

A series of experiments on the lateral torsional instability of single channels is presented. The channels are restrained by a purlin - angle cleat connection and subjected to a two point loading system in order to simulate a distributed load. Failure of the channels occurred by local buckling of the compression zone of the flange and web and lateral torsional buckling of the channels between points of lateral support. Tests have shown the purlin - angle cleat connection to be capable of restraining the frames from failing due to lateral-torsional buckling. This eliminates the idea of having fly-bracings, which is normally done in practice to restrain torsional instability.