Calculations of Earth Penetrators Impacting Soils
Final rept. Apr-Aug 1975
PACIFICA TECHNOLOGY DEL MAR CA
Pagination or Media Count:
A set of five computations were conducted which concerned earth penetrating weapons EPW impacting and penetrating two soil types. The penetrators were 5 feet long, 6.5 inches in diameter, and had 9.25 CRH tangent ogival heads, blunted by a 45 deg half angle cone, 0.5 inches in height. Impact speeds of 500 and 3500 ft.sec were considered. The calculations were carried to 4 feet of penetration in four of the five cases, and to 3 feet in the other. The penetrators were assumed to be rigid bodies. The computed deceleration and stresses on the penetrator are presented, as well as the deformation field created in the soils. Computing zone sizes of 4.13 and 3 cm were used 1.63 and 1.12 inches. The conclusion is reached that zoning finer than utilized in this or previous work is required to determine the correct decelerations and stresses on the vehicle. The zone size should be less than 2.5 cm in order to resolve the stress on the blunted nose and to determine the perturbation, which is considerable, on the stress and flow fields further back on the penetrator.
- Soil Mechanics