Various empirical dependencies in determining the parameters of penetrators permeating into soil-rock barriers

Abstract

The paper focuses on the use of high-speed penetrators in future study of the surface layer of various cosmic bodies, e.g. planets, asteroids, comets. In choosing the design parameters of penetrators, the penetration depth can be predicted according to empirical dependencies, which result from processing experimental data on the penetration of non-deformable impactors into various geomaterials. Such dependences obtained and used by both Russian and foreign researchers were comparatively analyzed. For a research module-penetrator with a diameter of 150 mm and a mass of 50 kg, we estimated the depth of its penetration into geomaterials with contrasting strength properties and its overload at initial interaction velocities of 100–1000 m/s. Findings of the research show that for the selected parameters of the penetrator and its speed of 1000 m/s, the penetration depth can range from several meters in the case of medium-hard rock to several tens of meters in the case of loose soil. Relying on some empirical dependences analyzed, we recorded the scale effect during penetration, which implies that the ratio of the penetration depths of geometrically similar impactors with a constant mass-diameter cube relation exceeds the coefficient of geometric similarity.