Buckling Fire Endurance of Steel Columns

Basic information on a temperature collapse of a building structure in fire can be obtained after fire‐endurance tests are carried out in special furnaces. The results of fire tests alone do not give rise to formulate the general rules that govern the process of building structure collapse in fire. It is therefore necessary to make a theoretical analysis of these tests. This may also be worthwhile for economical reasons, since the preparation and performing of the fire tests lasts several days and is rather expensive. In this paper, the differential equation of buckling steel columns during fire has been both formulated and solved. Rigidities and fire resistances of the columns have been also derived. The presented analysis of columns is based on a nonelastic model of steel and considers steel creep. With the help of proposed method it is possible to predict the results of fire‐endurance tests on given steel columns and generalize these results over the columns under different static diagrams, lengths, and loadings.