Effect of end distance and bolt number on bearing strength of bolted connections at elevated temperature

[[abstract]]To avoid the failure at bolted connections and ensure fire resistance at elevated temperature, this study examines the effect of end distance and bolt number on the bearing behavior of bolted connection from experimental results. In addition, numerical analysis is performed to evaluate the stress distribution at bolt hole with varied end distance at different temperature levels and to investigate the influence of stress concentration in longer joints. Based on the results of this study, it is found that the bearing strength increases linearly with end distance up to the value of 4d. And both AISC and Eurocode 3 underestimate the bearing stregnht of bolted plates at elevated temperature. A linear function of end distance is proposed for the bearing strength of bolted connections. The reduction factor for shear lag effect of AISC is recommended to modify the bearing strength for longer connections. It is also suggested to increase the end distance 3d to prevent tear-out failure at elevated temperature