Global buckling behaviour and design of stainless steel hexagonal hollow section columns

Owing to their high load-carrying capacity, ease of constructability and superior corrosion resistance, stainless steel polygonal hollow section members have great potential to be used in practical engineering. However, the absence of relevant design codes hinders their engineering applications. To address this issue, this paper conducts experimental and numerical studies on the flexural buckling behaviour and resistances of stainless steel hexagonal hollow section columns. A testing programme was carried out on ten column specimens designed with different cross-section dimensions and member lengths, together with tensile coupon tests and initial geometric imperfection measurements. A numerical modelling programme was then performed to develop and validate finite element models based on the test results. The validated FE models were adopted to carry out parametric studies to generate further numerical data to supplement the test data, which were then employed for the evaluations of design rules set out in the European code, American specification and ASCE standard. The evaluation results generally revealed that the European code and American specification resulted in an acceptable level of accuracy and consistency in predicting the flexural buckling resistances of stainless steel hexagonal hollow section columns, although some resistances of columns with low member slendernesses were overestimated, while the ASCE standard provided rather unsafe resistance predictions. Finally, a revised ASCE design buckling curve was proposed.