Research On Thermal Response Of Steel Structural Members In Fire

Structural fire is most common and dangerous in all fire types. Right now, the steel structure has become particular and important. Fire protection methods of the steel structure are an ineluctability problem relative to the reinforced concrete structure, because the action of high temperature will make the intensity and strength of the steel structure decrease quickly. So that, it's necessary to study the protection of steel structures from fire.In this thesis, the research on the functionary relationship of high temperature and the steel structural member, the thermal response of the steel structural member together with the flame-resistant capability of it and protection methods'influences on it were carried out by analyzing the heat-transfer relationship between fire and the steel structural member.Main contents of study listed as following:1. Based on the theory of heat transfer, radiation between fire and the steel structural member in indoor fire was analyzed, together with the convection conditions on the boundary of the member and the conduction model within it were also confirmed.2. Experimental study on the thermal response of the horizontal steel structural member was carried out utilizing the resistance furnace. The fire-resistant time of the steel column with fire retardant coating outside it would be more than 2 hours, and it's more safe in fire when the steel column with concrete in it and fire retardant coating outside it.3. Study on the mechanism of non-bulgy inorganic fire retardant coating is less in and abroad. In this thesis, tentative research was carried out that pyrogenation of fire retardant coating was analyzed: the heat-resistant effect of it would be weaken when the temperature was between 200℃and 400℃.4. The impacts of linear and nonlinear material character, sectional shape and mural thickness of the steel column on the thermal response of structural member were analyzed by ANSYS. Temperature of nodes was higher when material character was set to be nonlinear and the temperature difference would increase with pyrogenation going on; the fire-resistant capability of circinal steel structural member was inferior to that of quadrate steel structural; the temperature of the same node was higher when the...