Nonlinear Finite Element Analysis Of Planar Steel Frames In Fire

Compared with other structural forms，steel structure has a clear advantage of highstrength, light weight, space, good flexibility, therefore it is widely used in a variety of basicbuilding. But compared with the reinforced concrete structure,mixed structure and otherfire-resistant structure, steel structure has poor fire resistance, its material strength, elasticmodulus and the basic mechanical properties will sharply decline at high temperatures,oncebreaking out of fire, steel structure will has serious damage and even premature overallcollapse.Therefore, fire protection of steel structure, fire resistance research has importanttheoretical and social significance.At present, the domestic steel fire resistant design mainly based on fire resistant designmethod of the test, this method is difficult to simulate component in the overall structure ofthe load distribution, size, and the influence of end restraint,but determined by calculating theultimate bearing capacity of the steel structure fire resistance,we can be more reasonable todetermine the steel fire protection measures. Therefore, in-depth study based on thecalculation of the steel structure fire resistance design method has important theoreticalsignificance and practical value.The main research work of this article as follows1. Doing arrangements at home and abroad a number of existing research results，compared with analysis on the performance of the steel exposed to fire, Obtained formaterials (yield strength, modulus of elasticity) of fire resistant design of steel structurecomputing model.2.Using finite element software ANSYS to establish five different plane steel framemodel.3. Using finite element software ANSYS respectively makes temperature calculationsand mechanical analysis for the overall structure of the five flat steel frame, Research theweak link of the structure under fire hazard，get the refractory time and the criticaltemperature of structure and obtain the temperature field and deformation of the structure atdifferent times，therefore，more really reflect the structure fire resistance.