NASA Scientific and Technical Aerospace Reports

20040121011 NASA Langley Research Center, Hampton, VA, USA
Designing for Cost
Dean, Edwin B.; Unal, Resit; [1991]; 13 pp.; In English; 35th Conference of the American Association of Cost Engineers,
June 23-26, 1991, Seattle, WA, USA; Copyright; Avail: CASI; A03, Hardcopy
Designing for cost is a state of mind. Of course, a lot of technical knowledge is required and the use of appropriate tools
will improve the process. Unfortunately, the extensive use of weight based cost estimating relationships has generated a
perception in the aerospace community that the primary way to reduce cost is to reduce weight. Wrong! Based upon an
approximation of an industry accepted formula, the PRICE H (tm) production-production equation, Dean demonstrated
theoretically that the optimal trajectory for cost reduction is predominantly in the direction of system complexity reduction,
not system weight reduction. Thus the phrase ‘keep it simple’ is a primary state of mind required for reducing cost throughout
the design process.
Derived from text
Design to Cost; Cost Analysis; Complexity; Design Optimization
85
TECHNOLOGY UTILIZATION AND SURFACE TRANSPORTATION
Includes aerospace technology transfer; urban technology; surface and mass transportation. For related information see also 03 Air
Transportation and Safety, 16 Space Transportation and Safety, and 44 Energy Production and Conversion. For specific technology
transfer applications see also the category where the subject is treated.
20040111274 Prins Maurits Lab. TNO, Rijswijk, Netherlands
Characterisation of the Ballistic Resistance of Personal Body Armour by V(sub 0) and V(sub 50)
vanderMeer, B. J.; June 2004; 30 pp.; In Dutch
Contract(s)/Grant(s): A99/KL/471; TNO Proj. 014.12937
Report No.(s): TD-2004-0037; Copyright; Avail: Other Sources
Body armour ought to give maximum protection against particular projectiles. To select appropriate materials for these
body armors, sufficient information should be given by the test data obtained for these materials allowing a proper judgement
of the quality of the of the body armour materials in terms of protection. A frequently applied parameter is V50, which is the
projectile impact velocity at which there is a chance of 50% that the projectile will be defeated by the body armour. In this
report the 1.1 gr ‘fragment simulating projectile’ (FSP) has been applied. However, V50 alone is not sufficient to characterize
the body armour. How accurately has V50 been assessed? Usually, a minimum number of six to twelve firings are used to
assess V50. Two types of body armour can have the same V50, but may have different protection levels at other projectile
impact velocities. This is due to the width of the probability perforation curve. A smaller width allows for a better estimate
of the maximum protection level at practical impact velocities. Finally, a frequently mentioned drawback of V50 is that it is
not acceptable parameter for the user of the body armour. The ballistic limit velocity V(sub 0) is the proper parameter
expressing maximum protection against a particular projectile. The present report contains a generalisation of the method
published in the previous report PML 2003-A3 and should be considered the final report in this series. It finishes with a
recommended test method and the characterizing data that should be derived from the experimental data. These data include
both V0 and V50 and the confidence interval for V50.
Author
Armor; Projectiles; Ballistics; Fragments; Shrapnel; Fragmentation
88
SPACE SCIENCES (GENERAL)
Includes general research topics related to the natural space sciences. For specific topics in space sciences see categories 89 through
93.
20040111060 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA
Charge Storage, Conductivity and Charge Profiles of Insulators as Related to Spacecraft Charging
Dennison, J. R.; Swaminathan, Prasanna; Frederickson, A. R.; 8th Spacecraft Charging Technology Conference; March 2004;
17 pp.; In English; See also 20040111031; No Copyright; Avail: CASI; A03, Hardcopy
Dissipation of charges built up near the surface of insulators due to space environment interaction is central to
understanding spacecraft charging. Conductivity of insulating materials is key to determine how accumulated charge will
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