Impact and penetration of cylindrical bodies into dry and water-saturated sand

New results of the experimental-theoretical and numerical analysis of the dynamic behavior of dry and water saturated sand, impacted and penetrated by cylindrical strikers at the velocities from 50 to 450 m/s, are presented. Forces resisting penetration dependences into soil are determined using the inverse experiment technique, in which a container with sand impacts the end of a measuring bar with flat, hemispheric and conic heads. Based on the experimental-computational analysis of maximal and quasi-stationary values of the force resisting penetration of a flat-ended striker, parameters of dynamic compressibility and resistance to shear of compacted water-saturated sand are found. Using the obtained data the parameters of the Grigoryan's model were determined (identified), with the help of which numerical calculations of the resistance to penetration of impactors into the soil in an axisymmetric formulation of the mechanics of continuous media were carried out. It is shown that the identified mathematical model and the results of the computational experiment are in good agreement with the experimental data. It is found that, when compacted sand is practically fully water-saturated, its shearing properties degrade but remain substantial in the practically important range of impact interaction velocities.