MODELING OF THE PROCESS OF HIGH-SPEED INTERACTION OF A GRANULAR MEDIUM AND A ROD WITH A HEMISPHERICAL HEADBY THE METHOD OF DISCRETE ELEMENTS

This paper provides the results of numerical simulation of high-speed impact interaction of a non-deformable hemispherical body with a granular medium, which is a dense packing of steel spheres. The granular medium is considered as a set of individual particles, the motion and deformation of which is described by the discrete element method. This method uses the representation of the modeled material as a set of individual particles, with given set of elastic constants. This approach allows more efficient simulation of processes accompanied by large deformations and violations of the continuity of the medium than when using grid methods. Main principles of the numerical discrete element method, which have been widely used in recent years due to the development of computer technology are described with references to primary sources. An example of calculating the contact force between two interacting elastic spherical particles in the approximation of small deformations is given by decomposing it into normal and tangential components. In the simplest approximation, this force is the representing Hooke's law where the deformation of particles is considered as their spatial intersection. A general description of the numerical model and calculation methods is given. The results of modeling the process of normal high-speed impact interaction of a rigid rod with a hemispherical head with a deformable granular medium consisting of steel spherical spheres are presented taking into account the friction forces. An estimate is given of the contact forces from the discrete medium on the solid hemisphere. The results of numerical studies are compared with experimental data.