Stub column behavior of cold-formed high-strength steel circular hollow sections under compression

Abstract

This paper describes an experimental and numerical investigation on the stub column behavior of cold-formed high-strength steel (HSS) circular hollow sections (CHSs). A total of 16 stub column specimens fabricated from Q460, Q690, and Q960 steel plates were tested. Axial load-end shortening responses and failure modes of the stub column tests are presented and discussed. Nonlinear finite-element (FE) models were developed to replicate the stub column tests and subsequently employed to carry out comprehensive parametric studies to further examine the local buckling behavior considering various slenderness values and steel grades. The FE results were used together with experimental results to evaluate the applicability of current codified design methods in Eurocode, North American codes, and Australian standards to cold-formed HSS CHS stub columns. On the basis of the evaluation results, a new form of cross-sectional slenderness limit and a new set of design equations for more efficient designs were proposed and subsequently verified by means of statistical and reliability analyses.