Effect of quasi-total internal reflection of shock waves at an interface between two elastic media

The interaction of a spherical shock stress wave generated by a point explosion with a plane interface between two elastic media with different mechanical parameters is considered. Using the method of zero approximation of ray theory, it is shown that, after passage of a shock from a medium with smaller acoustic stiffness into a medium with greater acoustic stiffness, the stresses at the front of the refracted shock tend to infinity near the points of quasi-total internal reflection, and this can result in local failure of the media. An experiment with a two-component medium water-Plexiglas confirms the theoretically predicted phenomenon with sufficient accuracy. Timoshenko Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev 252057. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 1, pp. 21–27, January–February, 2000.