Numerical investigation and design method of cold-formed sorbite stainless steel circular tubes under uniaxial compression

Abstract

The recently developed novel high-strength sorbite stainless steel (S600E) combines the advantages of exceptional mechanical properties, high corrosion resistance, effortless weldability, and cost-effectiveness, granting remarkable competitiveness in stainless steel structures. The authors have conducted and published experiment results on S600E circular hollow section (CHS) columns under uniaxial compression, which serve as a foundation for the subsequent numerical analysis presented in this study. An extensive parametric study encompassed key variable parameters such as slenderness ratio, section size, and diameter-to-thickness ratio, culminating in 748 numerical models. Meanwhile, the ultimate strength obtained through finite element analysis (FEA) was utilized to evaluate the calculation methods prescribed by current European, Australian/New Zealand, and Chinese stainless steel structural design standards and the direct strength method (DSM) available in the literature. The result shows that the DSM can accurately predict the ultimate strength of CHS columns with an average error of 0.2%, while other specifications are slightly conservative. Then, the effective area calculation method was proposed in this paper, whose rationality was verified by meso finite element analysis. Moreover, a revised equation in Chinese code was proposed, which can improve the prediction accuracy by 9.2%. Finally, a reliability analysis was conducted to assess the safety levels of the design standards and DSM. The findings of this study can not only benefit the adoption of the high-strength stainless steel in the construction industry and therefore potentially mitigate carbon-emission-related environmental issues.