Dynamic stress-intensity factors of an in-plane shear crack in saturated porous medium

Based on the classical Biot theory of propagation of elastic waves in fluid-saturated porous media, two classes of plane problem are considered. One is the transient problem of a finite crack subjected to a suddenly applied in-plane shear, and another one is dealing with diffraction of transverse SV-wave by the same crack. The formulation utilizes the Laplace and integral transforms to reduce the mixed boundary-value problems to Fredholm integral equations of the second kind. The equations are then solved numerically for time and frequency dependent dynamic stress-intensity factors (mode II), and the influence of pore fluid on the dynamic stress-intensity factor is investigated. Pore fluid is found to have impact on the magnitude of the stress-intensity factor the extent of which depends on the two fluid parameter values, namely ratio of fluid mass with respect to the whole bulk mass and viscosity-to-permeability ratio. Comparisons of the solutions obtained from the present study with the corresponding known solutions of dry elastic medium are also provided to verify the validity of the present solution scheme.