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Trajectories
Published in Donald E. Carlucci, Sidney S. Jacobson, Ballistics, 2018
Donald E. Carlucci, Sidney S. Jacobson
The main armament of the last prewar US Heavy Cruisers (known as the tin-clads) was an 8 in./55 caliber weapon. The effective range of this weapon was 30,000 yards at an elevation of 40°43′. During the Second World War, there were many night actions in the Pacific where these weapons were used at an extremely short range (less than 10,000 yards). You are asked to create a firing table for this weapon at the short ranges. The muzzle velocity of the weapon/projectile/propellant combination is 2500 ft/s. The projectile is an armor-piercing, capped round with a diameter of 8 in. and a mass of 335 lbm. Since the range is short, we can assume the projectile behaves according to the flat fire assumption with a drag coefficient inversely proportional to the Mach number of K2 = 0.62 [unitless] (note that this is not really a great fit for this projectile). Assuming the flat fire assumption is valid for the trajectory, develop a firing table for the system to 10,000 yards in 1,000-yard increments. Assume standard sea level met data (ρ = 0.0751 lbm/ft3; a = 1,120 ft/s; R = 1716 [ft·lbf/slug · R]).
Numerical modeling of a human tissue surrogate SEBS gel under high velocity impacts: investigation of the effect of the strain rate in an elasto-hydrodynamic law
Published in Mechanics of Advanced Materials and Structures, 2022
Jianbo Shen, Lorenzo Taddei, Sebastien Roth
Finally, a typical blunt ballistic experiment [26] is replicated through finite element modeling. Figure 4 illustrates the gel wall displacement impacted by a rigid projectile. As is mentioned in previous SHPB modeling, the establishment of the FE model can be degraded to a quarter due to the symmetrical boundary conditions. The representative FE model of a rigid projectile impacting the SEBS gel is shown in Figure 5. The rigid round projectile is of 37 mm in diameter and with a mass of 140 g as was used in experiments [7, 27]. More precisely, the geometry size, mesh discretization as well as corresponding boundary conditions are presented in Figure 6. The dimension of the SEBS gel cube is 250 mm. Considering the high element distortions in ballistic impact simulations, the gel mesh is discretized more precisely. As illustrated in Figure 6, a relatively fine mesh is chosen in the impact region and a coarser mesh is sufficient for the region away from the impact center. The symmetrical boundary conditions are applied to symmetry planes of the gel cube and the backing plate in experiments is modeled by fixing the backing surface of the gel. Nevertheless, different from the previous two FE configurations, the Coulomb friction law in impact modeling is ignored as it has been revealed to have no influence on gel wall displacements [27]. Three different initial impact velocities of 12, 20 and 30 m/s are applied to the projectile respectively for repeating the experimental configurations.
Comprehensive characterization of firing byproducts generated from small arms firing of lead-free frangible ammunition
Published in Journal of Occupational and Environmental Hygiene, 2022
Ryan McNeilly, Jacob Kirsh, John Hatch, Ariel Parker, Jerimiah Jackson, Steven Fisher, John Kelly, Christin Duran
Prior to every firing event, the chamber was cleaned with deionized water. To clean the chamber, the lid was lifted, and the aluminum frame was removed. All internal surfaces were wiped down with a damp cloth and then left to dry for 10 min before prepping for the next firing event. The weapon was then mounted in the chamber, and a single round was loaded. For the M9 this round was loaded directly into the barrel, while the M4 was loaded using a magazine. For both weapon systems, the safety lever was released, making the weapon ready to fire prior to sealing the chamber.