Projectiles history

Test data are available for two experiments at different impact velocities in this configuration. In one of the tests the projectile impact velocity was 1.54 km/s, while in the second the impact velocity was 2.10 km/s. This test was simulated with the WONDY [60] one-dimensional Lagrangian wave code, and Fig. 9.21 compares calculated and measured particle velocity histories at the sample/window interface for the two tests [61]. Other test parameters are listed at the top of each plot in the figure. 

Most prominent of the waxed pressed expls, used extensively by the US Navy in their projectiles, is Compn A-3 (also used in Army HEP ammo). Ref 82 covers the history of the Navy s use of this expl (see also Vol 3, C474—C477 for additional information on Compns A-3, A-4 and A-5)... 

The history of incendiaries d incendiary projectiles thru WWII was reviewed earlier (Vol 7, 165). The principal advances in the intervening years have been in the wider use of metals which are known to,yield pyrophoric fragments, in the fabrication of incendiary bombs, and in the use of Zr, Ti and mischmetal. Early small arms incendiary mixts are reviewed in Ref 134, Table 5-7. As a pyrotechnic metal,... 

The history of artillery is the quest for precision and accuracy. Ballistic science is concerned with the properties of classical physical mechanics governing the motions of bodies under force. With artillery, these motions involve the mechanics of gun machinery, the dynamics of propellants, and the trajectory of discharged projectiles. The basic dynamics of artillery fire-whether bow and arrow, catapult, howitzer, or railroad gun-are based on Newton s second law of motion Net force is the product of the mass times the acceleration. Traditionally, for artillery this has meant that the amount of destruction was equal to weight of the projectile times how fast it could be propelled. In modern warfare, this destructive force is multiplied by adding explosives and submunitions to the projectile. 

Actually, crude oil straight from the ground has some value, but not a lot. Table 1 shows the history of petroleum before 1861. Before 1859, oil that was mined or that simply seeped up out of the ground was used to water-proof ships, as an adhesive in construction, for flaming projectiles, and in a wide variety of ointments. " ... 

Physically, this means that we are using the complete time history of lxn(t)) to obtain states of well-defined energy. But experimentally, one always effectively starts with the system at an arbitrary initial time (e.g., / = 0) when the projectile and target are localized inside a finite volume (the apparatus), and the collision is studied only until the collision products pass out of a finite volume of space, into the detector, say at time t. This suggests that we carry out a partial Fourier time-to-energy transform, ... 

The version of the apparatus used nowadays was introduced by Kolsky (1963), who added a second bar, from which the name Split Hopkinson Pressure Bar comes from the specimen of material to be tested is inserted between the two bars, as shown schematically in O Fig. 21.5a. The projectile, usually fired by means of a pneumatic gun, impacts the first bar (incident bar), generating the incident pulse which, at the bar/specimen interface, is partially reflected and partially propagates in the specimen. From the specimen, the pulse is transmitted to the second bar (transmitter bar). The situation is described graphically by the so-called Lagrangian diagram presented in O Fig. 21.5b. A concrete example of Split Hopkinson pressure bar is shown inO Fig. 21.6. The pulses are measured by means of strain gages placed on both incident and transmitter bar thus, their time history can be stored by means of a transient recorder, usually a digital oscilloscope or an acquisition board. From such measurements the stress (a), strain (e), and strain rate (s) in the specimen can be obtained as... 

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