Thermal shock resistance of functionally gradient solid cylinders

In this paper, an analysis of the transient thermo-mechanical behavior of a solid cylinder of functionally gradient material (FGM) under the convective boundary condition is presented theoretically. The analytical formula of the unsteady temperature distribution is derived by using the separation-of-variables method and hence the maximum thermal stress attained at the surface of the FGM solid cylinder as well as its time of occurrence can be calculated. Based on a local tensile stress criterion, the expression of critical temperature change ΔTc leading to the local tensile strength at the surface, which is designated as the thermal shock resistance parameter for FGM solid cylinder, is obtained. The effects of the radial distributions of thermo-physical properties on the thermal shock resistance of the FGM solid cylinder are investigated via numerical calculations in contrast to homogeneous solid cylinder, from which some suggestions on design of FGM solid cylinders with high thermal shock resistance are put forward.