Transient Solution of Heat and Moisture Transfer in a Functionally Graded Hollow Cylinder with Finite Length

In this article, temperature and moisture distributions in a finite-length hollow cylinder made of functionally graded material (FGM) under transient coupled hygrothermal condition was presented. The coupled equations of heat conduction and moisture diffusion were solved employing the Fourier series expansion method along the longitudinal direction, the differential quadrature method (DQM) along the radial direction, and the Newmark method for the time domain. Finally, the history of temperature and moisture potentials was obtained. The effect of coupled and uncoupled hygrothermal loading, grading index, and hygrothermal boundary conditions was illustrated in numerical examples. Results show that the difference between the coupled model and uncoupled model is more obvious in the moisture rather than the temperature. Also, the negative grading index increases the temperature and moisture. While the effect of the positive grading index is vice versa. Moreover, to have a more accurate analysis of the transient hygrothermal process, it is important to employ the coupled model.