Effects of Nuclear Earth-Penetrator and Other Weapons (2005) / Chapter Skim
Currently Skimming:
3 Earth-Penetrator Weapons
3 Earth-Penetrator Weapons
Pages 18-29
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 18... ...
Of the more than 3,000 EP tests conducted, there are currently 1,084 representative tests recorded in the SNL Earth Penetration Database. Complete characteristics of the penetrators -- physical characteristics, impact velocity, impact angle, impact angle of attack, penetrator path length, penetrator rest angle, test location, target site, target material, date of test, and associated programs -- are documented in this database.
|
From page 19... ...
BOX 3.1 Important Earth-Penetrator Weapon Parameters Physical Characteristics Impact Conditions · N: nose shape · V: impact velocity, m/s · d: body diameter, m · q: impact angle between velocity vector · L: total penetrator length, m (trajectory angle) and target surface · m: total penetrator weight, kg · a: angle of attack, angle between velocity vector · A: cross-sectional area, m2 (trajectory angle)
|
From page 20... ...
Internal components and subassemblies must be designed and packaged to survive highfrequency structural loading. The maximum impact velocities and hardest expected target materials determine the selection of nose shape.
|
From page 21... ...
EARTH-PENETRATOR WEAPONS 21 FIGURE 3.2 Limestone formations near Nashville, Tennessee, exhibiting layers of materials of different strengths. Photo courtesy of William J
|
From page 22... ...
In early 2000, two of the more widely used empirical equations were evaluated, and calculated depths were compared with large-scale tests of penetrators impacting into two different types of in situ rock formations at the Tonopah Test Range. Both of the equations predicted depths that agreed well with the Antelope Tuff and the Sidewinder Welded Tuff rock penetration data documented in the SNL Earth Penetration Database.3 One equation, developed by C.W.
|
From page 23... ...
0.7(Vs 30.5) Where D = depth of penetration in meters, = 0.0000175, Ks = scaling factor, S = empirical target constant, N = penetrator nose coefficient, m = penetrator mass in kilograms, A = penetra tor cross-sectional area in square meters, and Vs = impact velocity in meters per second.
|
From page 24... ...
0.76 0.76 0.76 1.30 1.30 1.30 8.00 8.00 8.00 caliber depth rock rock rock = = Maximum D rock rock rock CRH velocity; clay clay clay Estimated constant; Rock/Soil Classification Medium-strength Medium-strength Medium-strength Low-strength Low-strength Low-strength Silty Silty Silty impact target = V Empirically (SEPW) empirical density; = 3.1 Media EPW EPW EPW EPW EPW EPW EPW no.
|
From page 25... ...
In order to add credibility to these estimates, the following data were used in the calculations: the physical properties of the W86 P II EPW and SEPW designs, penetrability numbers for the geologic media supported by test data, and impact velocities no greater than the highest velocities documented in the SNL Earth Penetration Database. The results of an EPW bomb optimized with the highest m/A feasible, within a 2,700 kilogram weight limit, are also shown to illustrate the ability of a robust EPW to minimize axial deceleration.
|
From page 26... ...
For the targets of interest, optimum conditions were impact angles within 10 degrees of target normal, an angle of attack (angle between velocity vector and EPW centerline) of less than 2 degrees, and impact velocities around 245 meters per second.
|
From page 27... ...
Penetration tests with functional warhead electrical-system components and simulated nuclear assemblies were conducted at different impact velocities into hard soil and frozen soil to demonstrate B61-11 capability in the targets of interest. The classified military requirements for the B61-11 include limits for soil penetration capabilities, yield, center of gravity, reliability, stockpile quantities, and ballistic characteristics.
|
From page 28... ...
The study is allowed to address potential changes to internal components, as long as the changes do not require any nuclear certification tests. Owing to budget constraints the study is now limited to the robust nuclear earth penetrator (RNEP)
|
From page 29... ...
2003. "Comparison of Two Empirical Equations with Large Scale Penetrator Tests into In Situ Rock Targets," 11th International Symposium on Interaction of the Effects of Munitions with Structures, Mannheim, Federal Republic of Germany, May 5-9.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.