Analysis Of Composite Columns Under Thermal Effect

the study aim to Firstly, determination of the critical load that cause instability of the composite column in normal loading conditions. Secondly, determination of the resistance of the composite column in case of fire action. This resistance is expressed in terms of the critical temperature that causes instability of the composite column. In studying the stability of the column, the slenderness is the>main governing factor in determining the capacity of the column. So geometric non-linear analysis by the stiffness method was used in this study, in order to simulate accuratly the behaviour of the composite column in these situations. A numerical model was developed in order to calculate the current area and inertia, of the cross-section, along the numerical model can utilize the load in its general case, i.e., biaxial loading and the effect of temperature. A FORTRAN computer programe was developed to carry out this analysis. With regard to determination of the critical load in normal conditions. Two slenderness ratios of the column are considered in order to investigate the slenderness effect. These two columns were studied under 50 cases of uniaxial loading, and 36 cases of biaxial loading. br>action in which three different longitudinal temperature gradients arestudied in order to determine the worst one, which gives the lowest temerature resisted, and it is found that the uniform longitudinal temperature distribution is the worst, and it was then used to determine the critical temperature of the composite column under different cases of loading. Interesting results concerning the stability of the composite ’column were also obtained.