Buckling Reaction Analysis Of Steel Frame Construction Under Conflagration

Compared with other architectural form, steel structure has obvious advantages in thefollowing aspects as shorter construction period and lighter weight, especially now days, thesteel frame structure developed rapidly in life and production. But there are some importantfactors such as the weaker performance in resisting fire influence steel frame structure widelyapplication. The problems for fire protection and anti-fire of steel structure building have beenpaid more attentions by domestic and foreign scholars and a lot of research results have beenmade for any years. As the stability problem about steel frame structure bearing capacity inthe condition of fire, receiving the concern from domestic and foreign scholars. In this paper,the relevant research results are summarized and the main research work have been done asfollows:(1) Analysis methods to calculate the temperature field of steel structure componentsand the physical properties with thermodynamic performance of steel under high temperatureare summed up for the mechanical properties analysis of the structure component in thesubsequent chapters.(2) Based on heat conduction theory, the ultimate temperature are investigated when thesteel frame structure occur buckling damage in fire disaster, gaining the ultimate burning time.Through steel frame node transform into elastic hinge constraint, release axial stiffness androtational stiffness of node in high temperature, utilizing fundamental theory of structuremechanics analysis element internal forces of steel frame structure in fire disaster andacquiring the calculate conclusion, combining example analysis the variation circumstanceabout axial stiffness, rotational stiffness and internal forces of steel frame construction withelevated temperatures.(3) With the example, numerical calculations about bending stiffness coefficientexposed to fire in different time, deducing the express about calculation length coefficient ofsteel frame construction on the basis of bending stiffness coefficient, through the analysisresult of calculation length coefficient with steel frame construction in fire disaster, calculatedthe ultimate load of steel frame construction, come to the conclusion that tendency of ultimateload of steel frame construction with rising temperature as well as it is more reasonable about stress situation that according to the variation circumstance of constraint stiffness ratiojudging development of global stability capacity(4) FEM software ANSYS is used to calculate the global stability of the steel frameunder local fire condition. The deformation of component caused by temperature is examined,and the trend with fire temperature increasing of the deflection of framework beam and thelateral sway of framework column is obtained. The effect of the non-uniform temperaturedistribution of the member section on the global stability is investigated, and the comparativeanalysis with the result of mathematical mode was performed.