Behaviour of locally buckled singly symmetric columns

An experimental investigation into the behaviour of locally buckled cold-formed plain and lipped channel columns compressed between fixed and pinned ends is described in this paper. It is shown experimentally that local buckling does not induce overall bending of fixed-ended singly symmetric columns, as it does of pin-ended singly symmetric columns. Consequently, local buckling has fundamentally different effects on the behaviour of fixed-ended and pin-ended singly symmetric columns. In order to demonstrate this result experimentally, a series of tests was performed on plain and lipped channels brake-pressed from high strength structural steel sheets. The different effects of local buckling on the behaviour of fixed-ended and pin-ended channels are highlighted by comparing strengths, load-shortening and load-deflection curves, as well as longitudinal profiles of buckling deformations. The purpose of the paper is to demonstrate experimentally the different effects of local buckling on the behaviour and strengths of fixed-ended and pin-ended channels.