Effect of web holes on the web crippling capacity of cold-formed LiteSteel beams under End-Two-Flange load case

Abstract

LiteSteel (LSB) beams are made of two rectangular hollow flanges and a slender web. Although the flexural capacity and bending stiffness are enhanced due to hollow flanges, they are vulnerable to the web crippling failure under concentrated loads and reactions due to high web slenderness values. In current steel buildings, cold-formed steel sections with web holes have been used to accommodate service ducts in floor systems. These LiteSteel beams (LSBs) are innovative new sections, hence current web crippling equations cannot be used to predict the web crippling capacities of them. Keerthan et al. (2014, 2016) and Steau et al. (2015) proposed coefficients to the unified web crippling equation which is available in Australian/New Zealand standard (AS/ NZS 4600) and North American Specification (AISI S100) for unfastened and fastened supports, respectively for LSB sections without web holes under four load cases based on their experimental studies. However web crippling behaviour of these sections with web holes is still unknown under all four load cases. In past studies, the web holes are classified into two groups such as centred beneath and offset web holes to investigate their effect on the web crippling behaviour. This study investigates web crippling behaviour of LiteSteel beams with centred beneath and offset circular web holes with unfastened supports under End-Two-Flange load case (ETF) using finite element analysis in ANSYS. Accurate validations have been performed for five different web crippling datasets, and the parametric study was conducted using validated FE models. Web crippling equations were proposed for LiteSteel beams with centred beneath and offset web holes and without web holes based on 1067 FE model values.