Static strength of stainless steel K- and N-joints at elevated temperatures

This paper aims to investigate the static strength of stainless steel gap and overlapped K- and N-joints at elevated temperatures. A numerical parametric study was conducted on circular hollow section (CHS) K- and N-joints under axial loads in the braces at different temperatures ranging from 22 to 760 °C. A wide range of geometric parameters and chord preload ratios of CHS K- and N-joints using duplex, high strength austenitic and normal strength (AISI 304) stainless steel was investigated. The joint strength reduction was compared with reduction factors of yield stress and elastic modulus of stainless steel materials at elevated temperatures. A unified strength equation for CHS K- and N-joints at elevated temperatures was proposed by adopting the reduction factor of yield stress. The statistical analysis shows that the proposed strength equation is accurate for stainless steel K- and N-joints at elevated temperatures.