Transient Hygrothermal Stresses Induced in General Plane Problems by Theory of Coupled Heat and Moisture

A general finite element model is proposed to deal with the transient, hygrothermal stress problems by the linear theory of coupled heat and moisture that is required in the analysis of some porous and composite materials. The method consists of formulating and solving the problem in the Laplace transform domain by the finite element method and then numerically inverting the transformed solution to obtain the time domain response. Therefore, the transient solutions at any time could be evaluated directly. A number of examples are presented which demonstrate the accuracy, efficiency, and versatility of the proposed method. It can be found from the numerical results that the coupling effect between thermal and moisture is significant for composite material T300/5208. The maximum discrepancy between coupled and uncoupled solutions might be as high as 50 percent.