Analytical Solutions for Crack-Tip Higher Order Stress Fields in Thermal Barrier Coating
Analytical expressions for crack-tip higher order stress functions for a plane crack in a special functionally graded material (FGM), which has an variation of elastic modulus in 1 2 power form along the gradient direction, are obtained through an asymptotic analysis. The Poisson’s ratio of the FGM is assumed to be constant in the analysis. The higher order fields in the asymptotic expansion display the influence of non-homogeneity on the structure of crack-tip fields obviously. Furthermore, it can be seen from expressions of higher order stress fields that at least three terms must be considered in the case of FGMs in order to explicitly account for non-homogeneity effects on the crack- tip stress fields. These results provide the basis for fracture analysis and engineering applications of this FGM.
Prof. Alan Kin Tak Lau, Dr. J. Lu, Vijay K. Varadan, Fu-Kuo Chang, J.P. Tu and Pou Man Lam
Y. Dai et al., "Analytical Solutions for Crack-Tip Higher Order Stress Fields in Thermal Barrier Coating", Advanced Materials Research, Vols. 47-50, pp. 1023-1026, 2008