Local buckling strength and design of cold-formed steel beams with slotted perforations

Providing staggered slotted perforations to the Cold-Formed Steel (CFS) beams is a new approach being used in light gauge steel construction aiming to enhance both the fire and energy performances. However, slots in the web reduce the load-bearing capacity of CFS beams and existing studies do not provide a definite evaluation of the design expressions to determine the structural performance of slotted perforated CFS flexural members. Therefore, the present study aims to establish a methodology to determine the flexural capacity of staggered slotted perforated CFS beams subject to local buckling through developing three-dimensional Finite Element (FE) models. The developed FE models were subjected to validation against the related test data. Subsequently, the validated FE model was employed to conduct further parametric studies (432 FE models). Parameters include the dimensions of the CFS beams and staggered slotted perforations, rows and row groups of slots and yield strength. The effect of these factors on the local buckling capacity of the staggered slotted perforated CFS beams under bending is discussed. The paper concludes with a proposal of Direct Strength Method (DSM) based new design equations to predict the bending capacity of the CFS beams with staggered slotted perforations subject to local buckling and to enhance their commercial aspects.