EXPERIMENTAL RESEARCH AND ANALYSIS ON SIMILARITY MODEL FOR STEEL STRUCTURES UNDER FIRE

In order to analyze the fire response of a whole structure under fire using the method of scaled fire model, a similarity relation model for fire response of steel structures under fire was firstly developed in this paper based on the fire similarity and heat conduction theory. Then 1/4 and 1/8 scale fire test models and test specimens of steel frame structures were designed according to the relationships, and experimental studies were performed. Finally, comparative analysis of air temperatures, structure temperatures, structure deformation and structure failure was carried out. The results show that the similarity model is reasonable and accurate, and the bearing capacity and stability also meet the similarity model. The similarity model can be simplified by assuming the temperature similarity ratio of 1 or assuming the same similarity ratio of fire and structural time. The deformation of the maintenance structures and the external ventilation conditions should be strictly controlled in the scale fire tests, so as to ensure the similarity of the structure under high temperature during the post-failure stage.