Effect of fire high temperature on mechanical degradation and fracture behavior of steel

To study the property degradation and fracture behavior of steel after fire disaster, the heating test and the monotonic tensile test were carried out, the effect of test temperature( T ) and its duration on the mechanical parameter of post-fire specimen were investigated. The ductility degradation mechanism of post-fire steel was discussed according to its fracture analysis results. Results shown that, with increase of T, the size of dimple on the specimen fracture was gradually reducing, and the strength and deformation of the post-fire specimens were gradually deteriorating, this was to say, the ductility deteriorated gradually. Finally, a modified model established based on SMCS criterion was used to simulate the fracture behavior of post-fire steel, the effect of fire on SMCS parameters was revealed.