Mechanics of dynamic penetration into soil medium

Abstract

This paper presents a survey of the results of experimental and theoretical studies in the field of high-speed penetration into soil media, which were obtained in the Institute for Problems in Mechanics, Russian Academy of Sciences. New methods for determining the dynamic parameters of such media are proposed. The laws of trajectory refraction and ricochet in oblique penetration of a single body or a group of bodies into an elastoplastic medium are studies and the phenomenon of partial ricochet is described. The results of numerous experiments were used to discover the possibilities for controlling the process of cavity formation. The specific characteristics of penetration into a statically or dynamically perturbed medium were investigated. A series of experimental studies were performed to compare the penetration of axially symmetric and equivalent spatial (starshaped) bodies. The theoretical background was based on the principle of locality in the approximate description of the contact body-medium interaction, in which the problem of the body motion by inertia in a medium is reduced to the problem of the dynamics of a rigid elongated body with flow separation. The trajectories of curvilinear motions of bodied in an elastoplastic medium are modeled and classified by calibrating and testing the model in nontrivial experiments. Several criteria for stability of elongated body rectilinearmotion on infinite time intervals are formulated; as calculations showed, these criteria ensure the practical stability in the case of deep penetration.