The Modeling Of The Fire Resistance Of The Steel Framework

Along with the rapid development of the economic construction of our country, more and more application of steel structure, in the form of steel structure building structure also emerge in endlessly, people pay the much attention to steel structure resistance fire, many scholars at home and abroad begin to pay close attention to the steel structure fire resistance research. But our domestic current fire resistance design is usually based on the test component fire resistance design method, the method is simple and intuitive, but it has a high cost, and there are some defects, it has difficult to consider some factors, for example, the distribution and size of load、 the stress factors of component by fire produced and so on. Through practice found its practicality is not strong, while based on the calculation of the steel structure fire resistance design method can make up for the inadequacy of the above methods.This paper based on the calculation of the fire resistance design method, and using the finite element analysis software, the ambient temperature is the internationally used the ISO834standard heating up curve, Comparison and analysis the following content:(1) Establish a common steel frame in the finite element analysis software, its model of the steel beam and steel column section respectively using type and box type, Based on the two different cross section forms of steel beam and steel column model for temperature field calculation and analysis, compared to the cross section temperature and temperature change trends, studied the cross section form of the influence of the steel structure fire resistance.(2) Establish a three layer across the plane frame in the finite element analysis software, assume that the fire in different position of plane frame, focus on analysis fire resistance response between different working conditions, determine the time and critical temperature of refractory.Through the finite element analysis and calculation, the results show that:(1) Box section in the form of steel structure fire resistance is superior to the cross section of steel structure, box section is recommended in steel structure design of fire from structure.(2) For fire resistant analysis of plane frame, fire at the bottom of planar frame and occur in plane frame cross fire resistance is poor, the most unfavorable position of the fire room are pointed out.(3) According to the overall structure fire resistance and fire resistance performance analysis and comparison of individual components, found that the fire resistance of individual components do not reflect the overall structure fire resistance.Through the fire response analysis of steel frame structure, resistance research can provides some reference opinions for the future of the steel structure.