Safety Assessment Of The Performance-based Design About Light Portal Frame In Fire

The development of steel structure is so rapidly，mainly because of its distinctcharacteristics, such as high strength, good shock resistance, light weight andconvenient construction. But the weakness about steel structure is also fatal, that is thepoor fire resistance, the mechanical properties and material properties of steel willsharply fell down at high temperature under fire. Once the fire occurred, the steelstructure is prone to injury, damage or even collapse while causing huge losses andcasualties. Therefore, in view of the steel structure fire resistance and fire protectiondesign has a very important meaning and value.Currently, the method of fire resistant design of steel structure mainly containstwo kinds, one is based on the traditional test of fire resistance design method, thismethod is hardly to simulate the structure of the components of the load distributionand end restraint conditions, its result is fuzzy; and another is the based on calculationof the fire resistance design, this method can depict the structure of the overallperformance after fire which is more accurate and reasonable.The article is about the coupled thermo-mechanical analysis of nonlinear transientwhich is based on this study at home and abroad, through theoretical analysis andnumerical calculation, using the finite element analysis software--“ANSYS”, accordingto the performance of the specific requirements of the fire resistant design of gabledframes. Through the analysis of thermal and mechanical performance of portal frame,the change of steel structure in fire after the heat transfer law and fire resistanceperformance can be described, the structure of the relationship between stress andstrain and residual capacity can be obtained, and the procedure to evaluate the portalframe of performance-based design of fire safety system can be put forward. Throughthis study on fire resistance of steel frame structure, hoping to provide reference forfire resistant design of steel structure in the future.