Penetration of grout and concrete targets with ogive-nose steel projectiles

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.

A semi-empirical equation of penetration depth on concrete target impacted by ogive-nose projectiles

“…In Fig.6, the prediction results of this new equation are compared with those acquired experiments [10][11] and FEM simulation. Where, lines denote the prediction values, when stars and other symbol represent the numerical and experimental ones, respectively.…”

“…The outside surface is considered as a non-reflection boundary to simulate the semi-infinite effect. The various materials constants can be obtained from references [9][10][11]. Where, the density of the concrete target is 2320kg/m 3 , the unidirection compression strength is 58.4MPa.…”

Optimum Shape of High Speed Impactor for Concrete Targets Using PSOA Heuristic

“…A quite general solution to such problem was proposed by Forrestal et al [5][6][7] in the case of concrete targets. Four different models for the shield material are considered: incompressible elastic-plastic (model 1), incompressible elastic-cracked-plastic (model 2), compressible elastic-plastic (model 3) and compressible elastic-cracked-plastic (model 4).…”

“…Four different models for the shield material are considered: incompressible elastic-plastic (model 1), incompressible elastic-cracked-plastic (model 2), compressible elastic-plastic (model 3) and compressible elastic-cracked-plastic (model 4). Supposing the impactor's shape is axysimmetric with an unknown starting radius (flat nose), given length and final radius, (we call K 0 such class of shapes) and using the Forrestal et al [5][6][7] model, Ben-Dor et al [1][2][3]8] we investigated the maximum depth of penetration and found corresponding numerical solutions. From a mathematical point of view, the problem is reduced to a non-classical variational one for a functional that is a function of integrals of the unknown impactor's shape; the technique used to solve it is that of local variations, proposed by Banichuk et al [4].…”

Failure behavior of concrete subjected to high dynamic loading of new spiral projectile

“…Bernard [6][7] proposed an empirical formula for projectile penetrating into rock and concrete which contains a projectile head shape factor Caliber-Radius-Head, the density and uniaxial compressive strength of the target material, and the target rock quality index RQD (rock quality Designator) was brought in. Forrestal [8][9] , Frew 10 [17][18] , proposed a general nondimensional formula based on the dynamic cavity-expansion model to predict penetration depth subjected to the impact of a non-deformable projectile. He 19 , et al analysed the penetration process considering mass loss.…”