Scienceline Publications Journal of Civil Engineering and Urbanism 2252-0430 6 3 2016 May Buckling Analysis of Biaxially Compressed All-Round Simply Supported (SSSS) Thin Rectangular Isotropicplates using the Galerkin’s Method 48 53 http://www.ojceu.ir/main/attachments/article/52/J.%20Civil%20Eng.%20Urban.,%206%20(3)%2048-53,%202016.pdf EN David Ogbonna Onwuka Department of Civil Engineering, Federal University of Technology, Owerri, Imo State, Nigeria Owus Mathias Ibearugbulem Department of Civil Engineering, Federal University of Technology, Owerri, Imo State, Nigeria Stanley Emeka Iwuoha Department of Civil Engineering, Federal University of Technology, Owerri, Imo State, Nigeria Joan Ijeoma Arimanwa Department of Civil Engineering, Federal University of Technology, Owerri, Imo State, Nigeria Samuel Sule Department of Civil and Environmental Engineering, University of Port Harcourt, Rivers State, Nigeria This work studied the buckling analysis of biaxially compressed all-round simply supported (SSSS) thin rectangular isotropic plates using the Galerkin’s method. The study was limited to thin rectangular isotropic plates having aspect ratios ranging from 1 to 2. The general equation for the critical buckling load of a biaxially loaded plate, was formulated from the overall governing differential equation for plates, using the Galerkin’s method. The derived general equation, was expressed as the load in the x-axis in terms of that in the y-axis. This was done by means of a linear relationship which was obtained for the buckling load on the y- axis in terms of that on the x-axis. The SSSS plate deflection equation, was obtained using the polynomial series, and was substituted into the general equation of the critical buckling load of a biaxially loaded plate. This yielded the unique expression for the critical buckling load of a biaxially loaded SSSS plate. Different values (0 to 2) of aspect ratios and “k” (relationship constant between forces on the Y-axis and forces on the X-axis) values (0.1 to 1) were substituted into the critical buckling equation for an SSSS plate, and the critical buckling load coefficients were obtained. The critical buckling load coefficient of a square plate (i.e. at k equal to 1), was obtained as 19.754. When compared with the exact value (19.744) obtained by other researchers who used the trigonometric series, a percentage difference of 0.047 was discovered. At k equal to zero, and for different aspect ratios, the results of the present study showed a maximum percentage difference of 0.069 with those given in the literature. It was therefore concluded that this paper has provided the critical buckling load equation, and results for a biaxially loaded SSSS plates having different k values and aspect ratios, whose result has not been found in the literature. Buckling Analysis Plates Biaxial Forces Galerkin’s Method Boundary Condition