A Method to Analyze the Formation of Plastic Hinges in RC Structures under Fire Conditions

Abstract

RC structures are usually large, and it is arduous to use test methods to accurately analyse the redistribution of internal forces and development of plastic hinges during fires. This paper proposes a method for judging the formation and development of plastic hinges in the cross-sections of reinforced concrete structures under thermo-mechanical coupling effects. Using this method, the damage patterns of reinforced concrete structures under high temperatures are preliminarily studied. For reinforced concrete structures, the most severely damaged components during a fire may not necessarily be those on the floors exposed to the fire. For structural components on other floors, even if they remain at ambient temperature during the fire, the internal forces within them may undergo drastic changes due to the redistribution of internal forces throughout the structure. This can lead to reaching the yield limit or even the ultimate limit state, severely impacting the overall structural safety.