Aero-hygro-thermal stability analysis of higher-order refined supersonic FGM panels with even and uneven porosity distributions

In this paper, porosity-dependent aero-hygro-thermal instability of functionally graded (FG) panels is investigated by developing a higher-order refined shear deformable theory for the first time. Porosities are randomly distributed around the cross section of FG panel. Hygro-thermo-elastic material properties of porous FG panel are described using a modified power-law function accounting for even and uneven porosity distributions. Based on the presented refined shear deformation theory, it is possible to examine instability regions of thicker FG panels without using a shear correction factor. Employing extended Hamilton's principle, the governing equations of FG panel under supersonic airflow simulated via first-order piston theory are obtained. It is concluded that porosity volume fraction, type of porosities, hygro-thermal environment, material gradation and slenderness ratio have major roles on the prediction of divergence and flutter boundaries of porous FG panels. (C) 2017 Elsevier Ltd. All rights reserved.