ABSTRACT

Geometrical interpretation of the data obtained is given in Fig.3. It is evident that the plot of fracture zone volume as a function of force and energy parameters of impact can be divided into two nearly linear sections: the section AB exhibiting active growth of the impactor penetraton depth with increasing interaction force and energy, and the section of less active penetration. This indicates that there is a critical value of the impact energy parameters (which does depend on the rock structure and properties) above which the material resistance to impactor penetration grows considerably. This may be associated with an abrupt rise in material density under the impactor due to closing ("healing") of initial defects of the rock structure in zones of high compression stresses.