Thermo-elasto-plastic Stresses in Functionally Graded Ceramic/metal Composites with Two-dimensional Temperature Gradient

By utilizing the finite element method, the macroscopic as well as the microscopic thermal stress behaviors of a functionally graded material rectangular plate (FGP) subjected to partial heating conditions in a transient state are presented. The FGP has non-homogeneous thermal and mechanical material properties in the thickness direction, and consists of the particle-reinforced composite in the regions near both surfaces and a composite mixture in the intermediate region. A microscopic constitutive equation and the macroscopic analysis are used to treat the particle-reinforced regions and the intermediate region, respectively. Therefore, the FGP is analyzed by a combination of the macroscopic and the microscopic analyses. The elasto-plasticity and the temperature-dependent properties of the constituent materials as well as the residual stresses arising from the fabrication process are taken into account. The effects of the heating length of the partial heating conditions and the non-homogeneity function of the constituents are discussed in order to find out the optimum form of the gradation function for the FGM subjected to partial heating conditions in transient state. The two-dimensional transient temperature and two-dimensional transient thermal stresses, which include the macroscopic and microscopic components, for the FGP are analyzed and shown in figures. The character (tension or compression) of the macroscopic stresses is dependent on the functional form of gradation.