NASA Scientific and Technical Aerospace Reports

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