Critical factors influencing the fire performance of bolted double angle connections

Double angle connections are frequently used in steel framed structures and these connections, during a fire incident, play a critical role in transferring forces between structural members. There is lack of understanding on the response of bolted double angle connections under fire conditions. In this paper results from a set of numerical studies, carried out using finite element program ANSYS, on the fire behavior of bolted double angle connections are presented. In the analysis material and geometric nonlinearities, high temperature properties of steel and nonlinear contact interactions, are accounted for. The model is validated by comparing the predictions from the analysis with the published experimental results. The validated model was applied to carry out parametric studies to quantify the effect of critical factors on the fire performance of bolted double angle connections. Results from the parametric studies indicate that bolt-hole size, edge-distance, thermal gradient and slenderness of beam web have significant influence on the fire performance of bolted double angle connections.

► A model for tracing the fire response of double angle connections is proposed. ► Guidelines for modeling nonlinear contact interactions are presented. ► The predicted response parameters from the model arte validated against test data. ► Factors governing the fire response of double angle connections are identified.