Spring stiffness model for welded Connections exposed to fire

Considering the high sensitiveness of steel behaviour to fire, fire resistance of steel structures is of great importance and since the connections act as the main connector of frame members, the behaviour 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 behaviour of welded angle connections bare-steel joints 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 parameters code. Comparison of the results from the model with existing experimental data showed good agreement. The proposed model can be easily modified to describe the elevated temperature behaviour of other types of joint as well as joints under large rotations

Keywords:

Welded connection , Fire , Spring-stiffness model , Rotation-temperature curves , moment-rotation curves