Local buckling of S960 ultra-high strength steel welded I-sections subjected to combined compression and major-axis bending

• Published in: Engineering structures 2021-12, Vol.248, p.113213, Article 113213
• Main Authors: Su, Andi, Sun, Yao, Zhao, Ou, Liang, Yating
• Format: Article
• Language: English
• Subjects: Bending moments; Buckling; Combined compression and major-axis bending; Combined loading; Compression; Compressive strength; Design interaction curves; Eccentric loads; Eccentrically loaded stub column tests; Eccentricity; Failure load; Finite element method; Grade S960 ultra-high strength steel; High strength steel; High strength steels; Mathematical models; Mechanical properties; Numerical analysis; Numerical modelling; Specifications; Steel; Welded I-sections; Welding
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2021.113213

•The local buckling behavior of S960 UHSS welded I-sections under major-axis combined loading has been studied.•Major-axis eccentric compression tests on ten S960 UHSS welded I-section stub columns were conducted.•FE models were developed and validated against the test results and then used to perform parametric studies.•The codified design interaction curves were assessed, based on the test and FE data. This paper presents an in-depth experimental and numerical investigation into the local buckling behaviour of S960 ultra-high strength steel welded I-sections under combined compression and bending moment about the major principal axis. Two I-sections (I-120 × 120 × 6 and I-150 × 75 × 6) were considered in the experimental investigation, and for each I-section, five eccentrically loaded stub column tests were conducted under different initial loading eccentricities. The experimental results were then adopted in a numerical investigation for validating finite element models, by means of which parametric studies were conducted to generate additional numerical data over a wide range of cross-section dimensions and initial loading eccentricities (i.e. loading combinations). The obtained experimental and numerical results were used to evaluate the applicability of the relevant design interaction curves, as set out in the European code, American specification and Australian standard, to S960 ultra-high strength steel welded I-sections under major-axis combined loading. The evaluation results revealed that (i) the European code results in safe but slightly conservative failure load predictions, (ii) both the American specification and Australian standard lead to relatively accurate failure load predictions and (iii) all the three design codes offer a good level of design consistency.