Nonlinear flexural behaviour of efficient profiled cold-formed steel cross-sections

Abstract

In the past, the research work on cold-formed steel (CFS) members has mainly emphasized on either efficient stiffening of CFS sections or development of efficient cross-sectional profiles for their improved structural performance. Focusing separately on stiffening or profiling limits the capacity of CFS members due to instability failures. There is a need to strike a balance between efficient stiffening and efficient profiling of CFS sections in order to arrive at sections with better performance, economy and easy fabrication. This study deals with sequential efficient profiling of CFS sections subjected to flexure. Two series of built up sections, open sections (OS) and box sections (BS), were fabricated and tested under four point loading with same cross-sectional area. Test strengths, modes of failure, deformed shapes, load vs. mid-span displacements and geometric imperfections were measured and reported. The design strengths were quantified using North American Standards and Indian Standards for cold-formed steel structures. This study confirmed that easy and efficient profiling of CFS sections can result in cross-sections with higher performance as well as better economy.