Effect of High Temperatures on Austenitic Stainless Steel Circular Tubular T‐Joints

Abstract Effect of high temperatures on the load resistance of cold‐formed austenitic stainless steel circular hollow section (CHS) T‐joints with braces subjected to axial compression were investigated. The austenitic stainless steels are types of EN 1.4301 (AISI 304) and EN 1.4571 (AISI 316Ti having small amount of titanium). A finite element model (FE) was firstly developed and validated against the existing test results of austenitic stainless steel (EN 1.4301) CHS T‐joints at ambient temperature in terms of axial resistance, failure mode and load‐deformation response. An extensive parametric study was then carried out that covering the key parameters of β, τ , 2γ and high temperatures. It was found that the reduction factors of Young's modulus in material properties unconservatively predicted the reduction factors of the T‐joint strengths, while those of yield stress predicted conservatively at elevated temperatures. The applicability of the current design equations for ambient temperature condition were used to predict the strength of the CHS T‐joints at high temperatures. When calculating the strengths, the material properties at ambient temperature were substituted by using those at high temperatures. Overall, it was found that the CIDECT and the European design equations generally provided accurate strength predictions of the austenitic stainless steel CHS T‐joints at high temperatures up to 950°C.