Effect of geometrical imperfection on the thermomechanical behavior of functionally graded material rotating disk

The thermoelastic analysis of axisymmetric bending of rotating functionally graded material (FGM) disks, with and without imperfection, is presented. Material properties are assumed to be temperature dependent and graded in the thickness direction following a grading index power-law distribution. Theories of von Karman and first-order shear deformation were implemented to calculate the stress and displacement fields. Numerical results are given for evaluating the effects of temperature, material properties and imperfection on displacement and stress fields in a disk with roller-supported boundary conditions. Small and large deflection theories are considered to obtain the stress field and displacement field for the perfect and imperfect in FG disks and also in full metal (or full ceramic) disks. A series-form solution is used to solve the large-deflection nonlinear equations. The results are compared and validated with the results from the finite element method. It is observed that applying the initial geometric imperfection to a rotating solid disk would increase the value of radial stress, circumferential stress and vertical displacement.