The Research On Fire Behavior Of Restrained Steel H-column

The steel structures are widely used in modern high buildings or industrial factory due to their advantage properties such as light weight, well seismic performance and so on. However, the poor fire-resistant ability is also the weakness of the steel structures, in which its yield strength, when the temperature is up to 400℃, would decrease the half of the yield strength at the normal temperature, and the steel will lost most of its strength and rigidity when the temperature up to 600℃. As steel structures are playing more and more important roles in the constructional engineering, research on fire resistance and fire protection of the steel structures has been a hot topic in the academia and Engineering nowadays due to the poorly fire-resistant ability of steel.Considering the influence of non-uniform temperature field and the end restraints to the fire behavior of steel column, the new computational modeling of restrained H-steel column under the fire is proposed in the paper at first. Refering to the existing experiment of a restrained column, the finite element procedure MSC.marc are employed to compute the non-uniform temperature field and the end restraints of the column. Based on the above analysis, the behavior and failure mechanism of H-steel column in fire are analyzed, and discussed for various conditions. In addition, the effect of non-uniform temperature field, axial-load ratio and the end restraints of column are analyzed in detail. Due to the shortcoming of the existing fire experiment, the steel column under the constraint of steel beam is designed , and the experiment of behaviour of the column in fire is carried out. In the experiment, the behavior of the restrained steel columns are further researched, whose ends are axially restrained, unsymmetrically restrained and free, respectively. In the end, the fire behavior and failure mechanism of restrained steel columns are summed up , and some suggestions are obtained which can be used as basis of fire-resistance design of steel columns.