Analysis of steel bolted double angle connections at elevated temperatures

• Influence of fire temperatures on steel double angle connections are investigated.
• FE models are developed and validated against experimental data in literature.
• Important parameters are evaluated.
• Comparison with shear tab connections is made.

Double angle connections are one of the common simple beam-end framing connections used in steel structures, but current building standards do not provide much guidance on how to design these connections for fire. Development of such design methodologies is particularly hindered by the lack of adequate understanding of the strength and deformation capacities of double angle connections in fire. To address this issue, this paper presents key results of a computational study of the influence of fire temperatures on steel double angle connections. Computational models for double angle connections are developed in Abaqus and evaluated against experimental data from the literature at both ambient and elevated temperatures. An extensive study is then conducted to investigate different parameters that impact the behavior of double angle connection assemblies during a fire. A comparison is also made between the performances of double angle and shear tab connections at elevated temperatures. Results obtained in this study show that the main factors impacting the behavior of double angle connections at elevated temperatures are load ratio, initial cooling temperature, location of the double angle with respect to the beam neutral axis, and the gap distance. In addition, double angle connections showed better performance at elevated temperatures when compared to shear tab connections.