Testing, numerical modelling and design of S690 high strength steel welded I-section stub columns

Abstract

This paper describes a comprehensive testing and numerical simulation investigation into the material properties, membrane residual stresses and compression capacities of S690 high strength steel welded I-section stub columns. The testing programme was performed on eight welded I-sections fabricated from 5 mm thick S700MC high strength steel hot-rolled plates by means of gas metal arc welding, and included material tensile coupon tests, membrane residual stress measurements, initial local geometric imperfection measurements, and sixteen concentrically loaded stub column tests. A membrane residual stress distribution model for S690 high strength steel welded I-sections was firstly proposed, based on the experimentally measured results. In conjunction with the structural testing, a numerical modelling study was carried out, in which finite element models were initially developed and validated against the experimental results, and afterwards employed to conduct parametric studies, aiming at generating further structural performance data over a broader range of cross-section sizes. The obtained experimental and numerical data were used to evaluate the accuracy of the slenderness limits (for classifications of plate elements and cross-sections) and design rules for S690 high strength steel welded I-section stub columns, as set out in the European, American and Australian standards. The results of the evaluation revealed that the codified slenderness limits are accurate for the plate element and cross-section classifications of S690 welded I-sections in compression, and the established local buckling design provisions in the considered three codes result in precise and consistent cross-section compression resistance predictions for both non-slender and slender S690 welded I-section stub columns.