A theoretical analysis of FGM thin plates based on physical neutral surface

This paper presents a theoretical analysis to the FGM (functionally graded materials) thin plates based on the physical neutral surface. Under the assumption of changeable parameters such as the Young’s modulus E and the mass density ρ along the thickness of the plate, the physical neutral surface of a FGM plate is determined by the theory of thin plate when the Poisson’s ratio ν is assumed to be constant in whole plate. After that, the displacements in-surface (u0 and v0) can be neglected in small deflection problems, there is no stretching–bending coupling effect in constitutive equations of physical neutral surface thin plate theory in both small and large deflection problems, and governing equations and boundary conditions of physical neutral surface thin plate theory have the simple forms as those of classical thin plate theory about homogeneous isotropic materials, so the solution procedure of physical neutral surface thin plate theory is as easy as homogeneous isotropic plate. The validity of FGM thin theory based on physical neutral surface is verified by comparison with related literatures. Physical neutral surface thin plate theory has more merits in the engineering application, because it is easier and simpler than classical laminated plate theory based on geometric middle surface.