Abstract: The time-domain explicit finite element method for the wave motion of saturated two-phase medium is conditionally stable, and the stability of this kind of method can be evaluated by the transfer factor of transfer matrix of calculating formula. The smaller the value of transfer factor is, the better the stability of the explicit finite element method is. The stability of two time-domain explicit finite element methods for the wave motion of saturated two-phase medium is compared based on the transfer matrix of the calculating formula of the method, as various values of physical parameters of saturated two-phase medium are adopted. Calculating results show that the value of permeability coefficient has a remarkable effect on the distinction between the stability characteristic of the two methods. When a large value of permeability coefficient is adopted, the stability characteristic of the two methods does not distinguish obviously from each other. On the other hand, when a small value of permeability coefficient is adopted, the stability characteristic of the two methods will have a remarkable difference from each other. One method has more ascendant stability characteristic than that of the other method.

Key words: saturated two-phase medium, wave motion, time-domain explicit finite element method, stability, transfer matrix, permeability coefficient