Post-fire Behaviour of Stainless Steel Single Shear Bolted Connections

Abstract

abstract Stainless steel is used in many fields, including buildings, for its many advantages, including its resistance to corrosion, long life, high durability, low maintenance, and reuse. The high temperature affects the mechanical properties of stainless steel, and the joints are considered one of the most vulnerable parts in case the building is exposed to a fire risk. Therefore, there is a need to understand the behaviour of single shear bolt connections after exposure to high temperatures. This study deals with the effect of high temperatures on the mechanical properties of thin sheets of stainless steel and their behaviour in bolt connections after exposure to fire. The specimens were heated to high temperatures (600°C, 800°C and 1000°C) and cooled by air or water to simulate fire conditions and at different heating times (30, 60, 90 and 120) minutes. Coupons were used to find the mechanical properties (yield stress, ultimate stress, modulus of elasticity and elongation ratio) and specimens were used to find (ultimate load, failure type, axial displacement and curling displacement). The test results showed that after exposure to high temperatures there is a decrease in thickness. The yield stress improved for coupons of 2mm thicknesses when heating at a temperature of (600°C, 800°C and 1000°C) by 37%, 29% and 4%, and 31%, 22% and 10%, after the 120 min for the air-cooling and water-cooling, respectively, coupons of 4 mm thick that heated to (600 and 1000°C) were not affected and remained close to the reference coupon. The vi elongation ratio of the 2mm and 4mm coupons increased when the heating temperature was increased to 1000°C. The failure of the curling had no significant effect on the ultimate load of the specimens. The effect of heating was limited on the specimens at a temperature of 600°C and 800°C. It became clear at a temperature of 1000°C, where the decrease was 15% and 10% for the specimen 2 mm, 12% and 8% for the specimen 4 mm specimen when cooling with air and water, respectively, at a heating time of 120 minutes. The strength of water-cooled specimens did not show significant difference from that of aircooled specimens. The AISC approach for estimating the strength of the connection was lower than the experimental data