Structural behavior of right-angle two-planar tubular TT-joints subjected to axial loadings at fire-induced elevated temperatures

This paper aims to investigate the structural behavior of two-planar tubular TT-joints subjected to axial loading at fire induced elevated temperatures. A total number of 270 FE analyses were performed to investigate the effect of temperatures and dimensionless geometrical parameters (beta, gamma, and tau) parameters on the ultimate strength and initial stiffness. The joints were analyzed under axially compressive and tensile loads at five different temperatures (20 degrees C, 200 degrees C, 400 degrees C, 550 degrees C, and 700 degrees C). Up to now, there has not been any design equation available for determining the ultimate strength of two-planar tubular TT-joints at elevated temperature. Results of the parametric study were used to develop a set of design formulas, through nonlinear regression analyses, to calculate the ultimate strength of two-planar tubular TT-joints subjected to axial loading at elevated temperatures.