Experimental and numerical study of laser-welded stainless steel slender I-section beam-columns

Abstract

This paper reports on an experimental and numerical study on the structural behaviour and resistances of laser-welded stainless steel slender I-section beam-columns under combined compression and minor-axis bending. A testing programme was firstly conducted, including imperfection measurements and sixteen beam-column tests. Following the testing programme, a numerical modelling programme was conducted, where finite-element models were developed and validated. The validated finite-element models were then used to perform parametric studies to derive more numerical data. The obtained test and numerical data were employed to conduct an in-depth design analysis, where the relevant interaction curves in the European and American standards for laser-welded stainless steel slender I-section beam-columns were examined. The design analysis results indicate that the European and American interaction curves lead to significant inaccuracies and scattering of the ultimate load predictions, due to inappropriate bending end points. A new interaction curve is developed, anchored to a more accurate bending end point. The new curve is shown to offer greatly improved design accuracy and consistency over the current European and American curves.