No abstract

Summary -We conducted depth of penetration experiments into grout and concrete targets with ogive-nose steel projectiles. Powder guns launched 0.064 kg, 12.9 mm diameter projectiles into grout targets with unconfined compressive strengths of 13.5 M Pa (2.0 ksi} and 21.6 MPa (3.1 ksi). For the concrete targets, powder guns launched projectiles with length-to-diameter ratios of 10; a 0.48 kg, 20.3 mm diameter rod, and a 1.60kg, 30.5 mm diameter rod. Concrete targets had unconfined compressive strength of 62.8 M Pa (9.1 ksi) for the 0.48 kg rods and unconfined compressive strength of 51.0 MPa (7.4 ksi) for the 1.60 kg rods. For these experiments, penetration depth increased as striking velocity increased until nose erosion became excessive. Thus, we determined experimentally the striking velocities corresponding to maximum penetration depths. Predictions from a previously published model are in good agreement with data until nose erosion becomes excessive.

No abstract

No abstract

We conducted three sets of depth-of-penetration experiments with limestone targets and 3.0 caliber-radius-head (CRH), ogive-nose steel rod projectiles. The limestone targets had a nominal unconfined compressive strength of 60 MPa, a density of 2.31 kg/m3, a porosity of 15 percent, and a water content less than 0.4 percent. The ogive-nose rod projectiles with length-to-diameter ratios often were machined from 4340~45 and Aer Met 100 R. 53 steel, round stock and had diameters and masses of 7.1 mm, 0.020 kg; 12.7 mm, 0.117 kg; and 25.4 mm, 0.931 kg. Powder guns or a two-stage, light-gas gun launched the projectiles at normal impacts to striking velocities between 0.4 and 1.9 km/s. For the 4340 I&45 and Aer Met 100&53 steel projectiles, penetration depth increased as striking velocity increased to a striking velocity of 1.5 and 1.7 km/s, respectively. For larger striking velocities, the projectiles deformed during penetration without nose erosion, deviated from the shot line, and exited the sides of the target. We also developed an analytical penetration equation that described the target resistance by its density and a strength parameter determined from depth of penetration versus striking velocity data.