NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
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20040111167 Lockheed Martin Corp., Syracuse, NY, USA<br />
Roller Burnishing-A Cold Working Tool to Reduce Weld Induced Residual Stress<br />
Martin, J.; Feb. 2002; In English<br />
Report No.(s): DE2004-821697; LM-02K009; No Copyright; Avail: National <strong>Technical</strong> Information Service (NTIS)<br />
The possibility of stress corrosion cracking (SCC) in regions of tensile residual stress introduced by weld deposited<br />
material has been a concern where environmental effects can reduce component life. Roller burnishing, a form of mechanical<br />
cold-working, has been considered as a means of providing for residual stress state improvements. This paper provides a<br />
computational evaluation of the roller burnishing process to address the permanent deformation needed to introduce a<br />
desirable residual stress state. The analysis uses a series of incrementally applied pressure loadings <strong>and</strong> finite element<br />
methodology to simulate the behavior of a roller burnishing tool. Various magnitudes of applied pressure loadings coupled<br />
with different size plates <strong>and</strong> boundary conditions are examined to assess the degree <strong>and</strong> depth of the residual compressive<br />
stress state after cold working. Both kinematic <strong>and</strong> isotropic hardening laws are evaluated.<br />
NTIS<br />
Corrosion; Stress Corrosion Cracking; Tensile Stress; Residual Stress<br />
20040111171 Lawrence Livermore National Lab., Livermore, CA<br />
Overview of the National Ignition Facility Distributed Computer Control System<br />
Lagin, L. J.; Bettenhausen, R. C.; Carey, R. A.; Estes, C. M.; Fisher, J. M.; 2004; In English<br />
Report No.(s): DE2003-15005542; No Copyright; Avail: National <strong>Technical</strong> Information Service (NTIS)<br />
The Integrated Computer Control System (ICCS) for the National Ignition Facility (NIF) is a layered architecture of 300<br />
front-end processors (FEP) coordinated by supervisor subsystems including automatic beam alignment <strong>and</strong> wavefront control,<br />
laser <strong>and</strong> target diagnostics, pulse power, <strong>and</strong> shot control timed to 30 ps. FEP computers incorporate either VxWorks on<br />
PowerPC or Solaris on UltraSPARC processors that interface to over 45,000 control points attached to VME-bus or PCI-bus<br />
crates respectively. Typical devices are stepping motors, transient digitizers, calorimeters, <strong>and</strong> photodiodes. The front-end<br />
layer is divided into another segment comprised of an additional 14,000 control points for industrial controls including<br />
vacuum, argon, synthetic air, <strong>and</strong> safety interlocks implemented with Allen-Bradley programmable logic controllers (PLCs).<br />
The computer network is augmented asynchronous transfer mode (ATM) that delivers video streams from 500 sensor cameras<br />
monitoring the 192 laser beams to operator workstations. Software is based on an object-oriented framework using CORBA<br />
distribution that incorporates services for archiving, machine configuration, graphical user interface, monitoring, event<br />
logging, scripting, alert management, <strong>and</strong> access control. Software coding using a mixed language environment of Ada95 <strong>and</strong><br />
Java is one-third complete at over 300 thous<strong>and</strong> source lines. Control system installation is currently under way for the first<br />
8 beams, with project completion scheduled for 2008.<br />
NTIS<br />
Access Control; Active Control; Computer Networks; Ignition<br />
20040111172 Stanford Linear Accelerator Center, CA, USA<br />
Measurement of the Beta -\g Chi(sub s ) iota (sup +) iota(sup-) Branching Fraction Using a Sum over Exclusive Modes<br />
Aug. 07, 2003; In English<br />
Report No.(s): DE2003-815247; SLAC-PUB-10100; No Copyright; Avail: National <strong>Technical</strong> Information Service (NTIS)<br />
No abstract available<br />
Beta Particles; Weak Energy Interactions<br />
20040111173 Stanford Linear Accelerator Center, CA, USA<br />
Measurement of Inclusive Momentum Spectra <strong>and</strong> Multiplicity Distributions of Charged Particles at square root of s<br />
appxorimater 2-5 GeV<br />
2003; In English<br />
Report No.(s): DE2003-815243; SLAC-PUB-10095; No Copyright; Avail: National <strong>Technical</strong> Information Service (NTIS)<br />
Inclusive momentum spectra <strong>and</strong> multiplicity distributions of charged particles measured with the BESII detector at center<br />
of mass energies of 2.2, 2.6, 3.0, 3.2, 4.6 <strong>and</strong> 4.8 GeV are presented. Values of the second binomial moment, R(sub 2),<br />
obtained from the multiplicity distributions are reported. These results are compared with both experimental data from high<br />
energy e(sup+)e(sup -), ep <strong>and</strong> p(bar p) experiments <strong>and</strong> QCD calculations.<br />
NTIS<br />
Charged Particles; Center of Mass; Spectra<br />
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