Dynamic mechanical behavior of rocks containing double elliptical inclusions at various inclination angles

Abstract

Inclusions embedded in rock materials highly affect their mechanical response and fracture behavior under external loadings. In this study, dynamic uniaxial compressive tests were performed on sandstone specimens containing double elliptical inclusions with various inclination angles to investigate the effects of inclusion conditions on the dynamic mechanical properties and failure mechanism of rock specimens using a split Hopkinson pressure bar (SHPB) system and the digital image correlation (DIC) technique. The results reveal that the inclusions effectively enhance the dynamic strength of flawed specimens, but its variation trend versus the flaw inclination angle is similar to that of unfilled specimens. Remarkable transformations were observed in the initiation position and propagation path of cracks after filling the flaw, which can be represented by the vertical displacement distribution along the inclusion periphery. The interaction mechanism between the double inclusions was dominated by a shear slip crack at the flaw inclination angle of 45° and tensile cracks at the flaw inclination angles of 0° and 90°. The effect of inclusions on the final failure pattern becomes slight with the increasing flaw inclination angle.