Thermal buckling predictions of three types of high-order theories for the heterogeneous orthotropic plates, using the new version of DQM

Thermal buckling of the functionally graded orthotropic plates is a complicated phenomenon, due to existence of the bending-extension-shear coupling. Although no research has been published to date on this subject, limited theories can precisely model this coupling. Moreover, predictions of three distinct types of the high-order theories i.e., the refined four-parameter plate theory (RPT) with explicit shear-bending decomposition, Reddy’s third-order five-parameter theory (TOT), and the pth-order generalization of Reddy’s theory (GRT) are evaluated for the first-time, using present subject. The relevant governing differential equations are solved based on a new differential quadrature method (DQM). Results show that while the RPT utilizes less displacement parameters it is generally more accurate than the GRT and both are less accurate than TOT. The pre-buckling effects are also considered in the paper. A comprehensive parametric study is accomplished for a wide range of geometric and material properties parameters and various boundary conditions. Results reveal that for the present subject, the RPT and GRT may sometimes not lead to appropriate results. Furthermore, while the higher gradation exponents and orthotropy angles reduce the buckling temperatures, the aspect ratio may reverse this pattern.