Analysis of Thermoelastic Characteristics of a Rotating Circular Disk with an FGM Coating at the Outer Surface”, submitted by Faruk Ahmed Sohag

Abstract

This study investigates the thermoelastic characteristics of a thin circular functionally graded material (FGM) disk and a homogeneous disk with an FGM coating at the outer surface. Both the disks are assumed to have uniform thickness and a concentric circular hole. The FGM region of the disks are assumed to have power function and exponential variation of all the material properties, except the Poisson’s ratio, which is assumed to be constant throughout the disk. The disks are subjected to a temperature gradient field and an inertial force due to rotation of the disks. The incompatible eigenstrain developed in the disks due to the temperature gradient field and nonuniform coefficient of thermal expansion (CTE) is taken into account. Using the theories of two dimensional thermoelasticity, the problems are reduced to the solution of a second order differential equation which is converted into a system of simultaneous algebraic equations by developing a finite element model based on the variational approach and Ritz method. The finite element model is verified by comparing the finite element results with those obtained analytically by Timoshenko for a simple homogeneous disk under inertial force due to rotation only. Then the model is applied to investigate the thermoelastic characteristics of an Al/Al2O3 FGM disk and an Al disk with an Al/Al2O3 FGM coating. The numerical results demonstrate that the thermoelastic characteristics of the disks significantly depend on material distribution, temperature distribution, angular speed, and the FGM coating thickness. This suggests that these parameters should be taken into account in designing with an FGM grinding disk or cutter to ensure better performance in actual practice.