Experimental Study on Interaction of Distortional and Global Buckling of Stainless Steel Lipped Channel Columns

Abstract

This paper presents an experimental program to investigate distortional and global interaction buckling of stainless steel lipped channel columns in compression. Appropriate cross-sections and lengths were chosen so as to observe distortional-overall interaction buckling. In total, 21 buckling tests were conducted. After a brief introduction to the choice of column specimen geometries, key experimental results have been presented and discussed. The tests aim to study and observe the effect of distortional-global interactive buckling, study member under pin-ended boundary conditions, and provide benchmarks for design. Column tests were carried out with 13 position transducers monitoring displacements at key locations. A 3-D laser scanner was used to measure the imperfection shapes and magnitudes of the columns before testing. Material tests have been performed to determine the mechanical properties of stainless steel. Distortional–global interactive buckling of all columns is shown to be a failure mode. The experimental results are also used to evaluate the Australian Standard AS/NZS, North American Specification AISI, as well as formulation proposed by Becque and Rasmussen’s predictions, indicated that the Direct Strength Method (DSM) as described in AISI and AS/NZS for members undergoing distortional-overall interaction buckling are unconservative. Becque and Rasmussen’s curve is much closer to the test points than DSM in AISI and AS/NZS.