The simple model for welded angle connections in fire

Due to the high sensitivity of fire affected steel behavior, fire resistance of steel structures is of great importance. Moreover, since the connections act as the main means of integration of frame members, the behavior of steel connections in fire is significantly important. Considering the importance of this matter, this paper describes a spring-stiffness model developed to predict the behavior of welded angle connections made of bare-steel at elevated temperature. The joint components are considered as springs with predefined mechanical properties i.e. stiffness and strength. The elevated temperature joint’s response can be predicted by assembling the stiffness of the components which are assumed to degrade with increasing temperature based on the recommendations presented in the design code. Comparison of the results from the model with existing experimental data shows good agreement. The proposed model can be easily modified to describe the elevated temperature behavior of other types of joints as well as joints experiencing large rotations.