Failure wave effects in hypervelocity penetration

✍ Scribed by E.L. Zilberbrand; A.S. Vlasov; J.U. Cazamias; S.J. Bless; A.A. Kozhushko

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 589 KB
• Volume: 23
• Category: Article
• ISSN: 0734-743X
• DOI: 10.1016/s0734-743x(99)00142-6

✦ Synopsis

It has been known for several years that glass is a relatively effective armor against shaped charge jets [ 11 even though its performance against conventional long-rod projectiles is mediocre. Some of the authors have earlier postulated that this effect is due at least in part to an increase of the Rt value at hypervelocity. This enhancement is due to the fact that in long-rod penetration of brittle materials, a failure wave is generated in front of the penetrator which prematurely damages the material; however, if the penetrator is supersonic relative to this failure velocity, penetration is always occurring in intact material. Consequently, the true strength of a brittle material is only measured in hypervelocity experiments. In order to avoid the uncertainties of analyzing shaped charge penetration data, we have conducted experiments with L/D = 10 W alloy rods (p = 17.2 g/cm3) against glass targets (p = 2.5 g/cm3) to unambiguously search for this effect. In low velocity experiments, the penetration was essentially hydrodynamic, while above 3.9 km/s, the Rt-Y value was on the order of 5.7 to 7.2 GPa. This substantiates the failure wave hypothesis.