The Complementary Functions Method Solution to the Functionally Graded Polar Orthotropic Rotating Hyperbolic Disks with Both Radially and Circumferentially Aligned Fibers

Abstract

In the present study, efforts have been made to numerically evaluate elastic displacements and stresses in a convergent or divergent hyperbolic disk subjected to a centrifugal force of constant circular velocity. The disk material is assumed to be continuously radially functionally graded (FG) with two orthotropic materials based on the simplest Voigt rule with a power of volume fraction of two constituents. The fibers are assumed to be aligned along either radial (RR) or circumferential (CR) directions. Having been a second order differential equation with variable coefficients, the governing equation so-called Navier equation is first derived and then put in the form of two differential equations of first order. These two ordinary differential equation set is originally solved based on the initial value problem (IVP) by employing the Complementary Functions Method (CFM). The numerical results are verified with the corresponding benchmark results for uniform thickness FG polar orthotropic disks. The radial variation of the elastic fields in a hyperbolic disk is investigated for several boundary conditions, disk profile parameters, and the gradient parameter for both the radially and circumferentially aligned fibers. Some numerical results are also presented. Under the case that is considered in this study, it is revealed that the CR disk offers much higher elastic fields than RR disk under all boundary conditions. For a composite rotating disk rotating at a constant speed, it will be better to align fibers along the radial directions, to use convergent disk profiles, and to locate the material having higher radial stiffness at the outer surface. It is also disclosed that the location of the maximum Von-Mises equivalent stress in fixed-free disks varies regarding the fiber orientation.