Abstract: In order to improve the accuracy of the numerical substructure in the hybrid simulation of fire resistance, combined with the model updating technology, the hybrid simulation of fire resistance based on temperature field updating is carried out. A two stories and two spans steel frame model under fire is established to identify the measured temperature parameters in the experimental substructure. The element node temperature of the same part of the numerical substructure is updated to improve the calculation accuracy of the numerical substructure in the hybrid simulation. The results show that the method can update the temperature field of the model according to the data of the test substructure and analyze the fire resistance of the structure. The calculated fire resistance limit and ultimate stress state are in good agreement with the overall structure simulation. The error of fire resistance limit time is 7%, and the error of ultimate state stress is 1%. Therefore, the method proposed in this paper is more reliable and can provide a reference for further improving the applicability of the structural fire resistance hybrid test method.

Key words: steel frame, fire resistance of structure, hybrid simulation, model updating, fire resistance limit