Experimental studies of the shear behavior and strength of LiteSteel beams with stiffened web openings

LiteSteel beam (LSB) is a new cold-formed steel hollow flange channel section produced using a patented manufacturing process. It is commonly used as flexural members in residential, industrial and commercial buildings. Current practice in flooring systems is to include openings in the web element of floor joists or bearers so that building services can be located within them. Test results have shown that the shear capacity of LSBs can be reduced considerably by the inclusion of web openings. A cost effective method of eliminating the detrimental effects of a large web opening is to attach suitable stiffeners around the web openings of LSBs. A detailed experimental study consisting of 17 shear tests was therefore undertaken to investigate the shear behavior and strength of LSBs with stiffened circular web openings. Both plate and stud stiffeners with varying sizes and thicknesses were attached to the web elements of LSBs using a number of screw-fastening arrangements in order to develop a suitable stiffening arrangement for LSBs. Simply supported test specimens of LSBs with an aspect ratio of 1.5 were loaded at mid-span until failure. This paper presents the details of this experimental study of LSBs with stiffened web openings, and the results of their shear capacities and associated behavioral characteristics. Suitable screw-fastened plate stiffener arrangements have been recommended in order to restore the original shear capacity of LSBs.

► Shear strength of a hollow flange channel with stiffened web openings was studied.
► Shear tests investigated various stiffener types to recover the lost shear capacity.
► The plate stiffeners based on AISI recommendations were found to be inadequate.
► A screw-fastened plate stiffener system is proposed to restore the shear strength.
► Simple predictive equations are proposed for the optimum plate stiffener sizes.