Creep Behavior in High Strength Q460 Steel

Abstract:

In order to investigate the effect of creep in high strength Q460 steel on the fire resistance of structures, creeptime curves for high strength Q460 steel under various temperature and stress was tested by using creep testing setup. According to the test data, creep models for high strength Q460 steel were proposed based on current creep models. The fire resistance of axially compressed high strength Q460 steel column was analyzed by employing finite element modeling after taking material properties and creep at elevated temperatures into consideration. The study shows that the creep deformation under the action of temperature and stress in high strength Q460 steel is significant, and at the same temperature and time, the creep increase obviously with rise of stress. After considering the effect of creep, fire duration of steel column decrease seriously under the fire exposure to ISO834 standard temperature curve. At a certain temperature, there is a pronounced reduction in load bearing capacity of steel column with the increase of time for fire exposure. Therefore, in the design of load bearing capacity of steel column, the time lasting in fire should be taken into consideration.