Experimental study of shear strength of cold-formed channels with an aspect ratio of 2.0

Shear behaviour of cold-formed steel beams with an aspect ratio (shear span/web depth) of 1.0 has been studied thoroughly, mainly using central point load tests. However, for beams with longer aspect ratios, the effect of bending causes reduction of shear capacity and alters the failure modes. This paper summarises experiments recently performed at the University of Sydney on channel section members using a new test configuration to minimize bending moments. Shear strength close to pure shear capacity can be therefore reached even at an aspect ratio of 2.0. The test results were compared with the strength predictions using the current direct strength method (DSM) of design for shear specified in the North American specification for the design of cold-formed steel structural members, AISI S100:2016 and the Australian/New Zealand Standard for cold-formed steel structures, AS/NZS 4600:2018. A good agreement between the experimental results and the predicted values has confirmed the viability of the DSM design rules for structures with aspect ratios up to 2.0. Numerical models were developed to foresee potential issues prior to the experimental work, and were subsequently calibrated against the tests to produce reliable results.