Finite Element Analysis on the Block Shear Strength of Double-Shear Bolted Connection with Stainless Steel and Carbon Steel Under Post Fire Condition

This study evaluated the structural performance of four-bolted connections (2 by 2 array) of stainless steel and carbon steel, which are expected to undergo physical changes after a fire, using existing material test data under post-fire condition to perform finite element (FE) analysis. The FE analysis model was developed to investigate the structural behavior of stainless steel and carbon steel double-shear bolted connection in a cooled state after exposure to high temperatures. The validation of FE analysis procedures was verified through the comparison of test results in the literature and analysis predictions. To examine the structural behavior of bolted connections in a cooled state following heating to four specific target temperatures, parametric FE analysis was also performed. Material models incorporating the post-fire material properties of austenitic stainless steel (corresponds to EN 1.4404) and carbon steel (corresponds to ASTM A992) tested by the previous studies were input, and the analysis was conducted under monotonic loading conditions. The target temperatures were set at 20 °C, 400 °C, 700 °C, and 1000 °C, and the structural performances of the double-shear bolted connections with block shear fracture, considering the material properties of both steels cooled in air after reaching these temperatures were compared and the strength reduction ratio between high temperatures (400 °C, 700 °C, and 1000 °C for stainless steel and 400 °C and 700 °C for carbon steel) and ambient temperature (20 °C) was recommended.