SCAN_59-01

59-01 APPLIED MATHEMATICS
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Probabilistic Methods for Structural Reliability and Risk
Document ID:
20090022153
Report #:
Paper No. 2413, E-16477
Available Online:
http://hdl.handle.net/2060/20090022153
Sales Agency:
CASI Hardcopy A02 No Copyright
Author(s):
Chamis, Christos C. (NASA Glenn Research Center)
Published:
20080602
Source:
NASA Glenn Research Center (Cleveland, OH, United States)
Pages:
10
Contract #:
None
Abstract:
A probabilistic method is used to evaluate the structural reliability and risk of select metallic and composite structures. The method is a multiscale, multifunctional and it is based on the most elemental level. A multi-factor interaction model is used to describe the material properties which are subsequently evaluated probabilistically. The metallic structure is a two rotor aircraft engine, while the composite structures consist of laminated plies (multiscale) and the properties of each ply are the multifunctional representation. The structural component is modeled by finite element. The solution method for structural responses is obtained by an updated simulation scheme. The results show that the risk for the two rotor engine is about 0.0001 and the composite built-up structure is also 0.0001.
Language:
English
Notes:
ECCM13 European Conference on Composite Materials Stockholm 2-5 Jun. 2008

Title:
Resolving the Azimuthal Ambiguity in Vector Magnetogram Data with the Divergence-Free Condition: Theoretical Examination
Document ID:
20090022172
Report #:
None
Available Online:
http://dx.doi.org/10.1007/s11207-007-9096-1
Sales Agency:
Other Sources Copyright
Author(s):
Crouch, A. (Northwest Research Associates, Inc.) Barnes, G. (Northwest Research Associates, Inc.)
Journal:
Solar Physics, Volume: Volume 247 , Page: 25-37
Published:
20080101
Source:
Northwest Research Associates, Inc. (Boulder, CO, United States)
Pages:
1
Contract #:
NNH05CC75C
Abstract:
We demonstrate that the azimuthal ambiguity that is present in solar vector magnetogram data can be resolved with line-of-sight and horizontal heliographic derivative information by using the divergence-free property of magnetic fields without additional assumptions. We discuss the specific derivative information that is sufficient to resolve the ambiguity away from disk center, with particular emphasis on the line-of-sight derivative of the various components of the magnetic field. Conversely, we also show cases where ambiguity resolution fails because sufficient line-of-sight derivative information is not available. For example, knowledge of only the line-of-sight derivative of the line-of-sight component of the field is not sufficient to resolve the ambiguity away from disk center.
Language:
English

Title:
Compatibility of Segments of Thermoelectric Generators
Document ID:
20090022338
Report #:
NPO-30798
Available Online:
http://www.techbriefs.com/component/content/article/5292
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Snyder, G. Jeffrey (California Inst. of Tech.) Ursell, Tristan (California Inst. of Tech.)
Journal:
NASA Tech Briefs, June 2009, Page: 27-28
Published:
20090601
Source:
California Inst. of Tech. (Pasadena, CA, United States)
Pages:
2
Contract #:
None
Abstract:
A method of calculating (usually for the purpose of maximizing) the power-conversion efficiency of a segmented thermoelectric generator is based on equations derived from the fundamental equations of thermoelectricity. Because it is directly traceable to first principles, the method provides physical explanations in addition to predictions of phenomena involved in segmentation. In comparison with the finite-element method used heretofore to predict (without being able to explain) the behavior of a segmented thermoelectric generator, this method is much simpler to implement in practice: in particular, the efficiency of a segmented thermoelectric generator can be estimated by evaluating equations using only hand-held calculator with this method. In addition, the method provides for determination of cascading ratios. The concept of cascading is illustrated in the figure and the definition of the cascading ratio is defined in the figure caption. An important aspect of the method is its approach to the issue of compatibility among segments, in combination with introduction of the concept of compatibility within a segment. Prior approaches involved the use of only averaged material properties. Two materials in direct contact could be examined for compatibility with each other, but there was no general framework for analysis of compatibility. The present method establishes such a framework. The mathematical derivation of the method begins with the definition of reduced efficiency of a thermoelectric generator as the ratio between (1) its thermal-to-electric power-conversion efficiency and (2) its Carnot efficiency (the maximum efficiency theoretically attainable, given its hot- and cold-side temperatures). The derivation involves calculation of the reduced efficiency of a model thermoelectric generator for which the hot-side temperature is only infinitesimally greater than the cold-side temperature. The derivation includes consideration of the ratio (u) between the electric current and heat-conduction power and leads to the concept of compatibility factor (s) for a given thermoelectric material, defined as the value of u that maximizes the reduced efficiency of the aforementioned model thermoelectric generator.
Language:
English

59-02 DATA PROCESSING
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Distributed Observer Network
Document ID:
20090022245
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 96-97
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) ASRC Aerospace Corp. (United States) Valador, Inc. (Rockville Centre, NY, United States)
Pages:
2
Contract #:
None
Abstract:
NASA s advanced visual simulations are essential for analyses associated with life cycle planning, design, training, testing, operations, and evaluation. Kennedy Space Center, in particular, uses simulations for ground services and space exploration planning in an effort to reduce risk and costs while improving safety and performance. However, it has been difficult to circulate and share the results of simulation tools among the field centers, and distance and travel expenses have made timely collaboration even harder. In response, NASA joined with Valador Inc. to develop the Distributed Observer Network (DON), a collaborative environment that leverages game technology to bring 3-D simulations to conventional desktop and laptop computers. DON enables teams of engineers working on design and operations to view and collaborate on 3-D representations of data generated by authoritative tools. DON takes models and telemetry from these sources and, using commercial game engine technology, displays the simulation results in a 3-D visual environment. Multiple widely dispersed users, working individually or in groups, can view and analyze simulation results on desktop and laptop computers in real time.
Language:
English

Title:
Service Management Database for DSN Equipment
Document ID:
20090022349
Report #:
NPO-45013
Available Online:
http://www.techbriefs.com/component/content/article/5290
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Zendejas, Silvino (California Inst. of Tech.) Bui, Tung (California Inst. of Tech.) Bui, Bach (California Inst. of Tech.) Malhotra, Shantanu (California Inst. of Tech.) Chen, Fannie (California Inst. of Tech.) Wolgast, Paul (California Inst. of Tech.) Allen, Christopher (California Inst. of Tech.) Luong, Ivy (California Inst. of Tech.) Chang, George (California Inst. of Tech.) Sadaqathulla, Syed (California Inst. of Tech.)
Journal:
NASA Tech Briefs, June 2009, Page: 25
Published:
20090601
Source:
California Inst. of Tech. (Pasadena, CA, United States)
Pages:
1
Contract #:
None
Abstract:
This data- and event-driven persistent storage system leverages the use of commercial software provided by Oracle for portability, ease of maintenance, scalability, and ease of integration with embedded, client-server, and multi-tiered applications. In this role, the Service Management Database (SMDB) is a key component of the overall end-to-end process involved in the scheduling, preparation, and configuration of the Deep Space Network (DSN) equipment needed to perform the various telecommunication services the DSN provides to its customers worldwide. SMDB makes efficient use of triggers, stored procedures, queuing functions, e-mail capabilities, data management, and Java integration features provided by the Oracle relational database management system. SMDB uses a third normal form schema design that allows for simple data maintenance procedures and thin layers of integration with client applications. The software provides an integrated event logging system with ability to publish events to a JMS messaging system for synchronous and asynchronous delivery to subscribed applications. It provides a structured classification of events and application-level messages stored in database tables that are accessible by monitoring applications for real-time monitoring or for troubleshooting and analysis over historical archives.
Language:
English

Title:
Synthetic Foveal Imaging Technology
Document ID:
20090022352
Report #:
NPO-44209
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Hoenk, Michael (California Inst. of Tech.) Monacos, Steve (California Inst. of Tech.) Nikzad, Shouleh (California Inst. of Tech.)
Journal:
NASA Tech Briefs, June 2009, Page: 12-13
Published:
20090601
Source:
California Inst. of Tech. (Pasadena, CA, United States)
Pages:
2
Contract #:
None
Abstract:
Synthetic Foveal imaging Technology (SyFT) is an emerging discipline of image capture and image-data processing that offers the prospect of greatly increased capabilities for real-time processing of large, high-resolution images (including mosaic images) for such purposes as automated recognition and tracking of moving objects of interest. SyFT offers a solution to the image-data processing problem arising from the proposed development of gigapixel mosaic focal-plane image-detector assemblies for very wide field-of-view imaging with high resolution for detecting and tracking sparse objects or events within narrow subfields of view. In order to identify and track the objects or events without the means of dynamic adaptation to be afforded by SyFT, it would be necessary to post-process data from an image-data space consisting of terabytes of data. Such post-processing would be time-consuming and, as a consequence, could result in missing significant events that could not be observed at all due to the time evolution of such events or could not be observed at required levels of fidelity without such real-time adaptations as adjusting focal-plane operating conditions or aiming of the focal plane in different directions to track such events. The basic concept of foveal imaging is straightforward: In imitation of a natural eye, a foveal-vision image sensor is designed to offer higher resolution in a small region of interest (ROI) within its field of view. Foveal vision reduces the amount of unwanted information that must be transferred from the image sensor to external image-data-processing circuitry. The aforementioned basic concept is not new in itself: indeed, image sensors based on these concepts have been described in several previous NASA Tech Briefs articles. Active-pixel integrated-circuit image sensors that can be programmed in real time to effect foveal artificial vision on demand are one such example. What is new in SyFT is a synergistic combination of recent advances in foveal imaging, computing, and related fields, along with a generalization of the basic foveal-vision concept to admit a synthetic fovea that is not restricted to one contiguous region of an image.
Language:
English

Title:
Aviation Safety: NASA's National Aviation Operations Monitoring Service Project Was Designed Appropriately, but Sampling and Other Issues Complicate Data Analysis
Document ID:
20090022360
Report #:
GAO-09-112
Sales Agency:
CASI Hardcopy A05 No Copyright
Author(s):
(Author(s) Not Available)
Published:
20090301
Source:
Government Accountability Office (Washington, DC, United States)
Pages:
100
Contract #:
None
Abstract:
To describe the history and nature of the National Aviation Operations Monitoring Service (NAOMS) project, we researched, reviewed, and analyzed related material posted on several NASA Web sites and provided to us directly by NASA and its contractor for NAOMS. We reviewed relevant documents on the House of Representatives' Committee on Science and Technology Web site. We examined relevant documents produced by the Battelle Memorial Institute (Battelle), National Academies, and others as well as information produced for the National Research Council. In addition, we reviewed a number of relevant reports, articles, correspondence, and fact sheets on the NAOMS project and air safety. Many of the publicly available materials we reviewed are named in the bibliography at the end of this report. As a monitoring tool, NAOMS was intended to point air safety experts toward trends, to help show FAA and others where to look for causes or extremely rare safety events in other datasets. As a research and development project, NAOMS was a successful proof of concept. However, the data that NASA collected under NAOMS have not been fully analyzed or validated by project staff or aviation safety stakeholders. Depending on the research objective, proper analysis of NAOMS data would require multiple adjustments. Additionally, because of their age, existing NAOMS data would most likely not be useful as indicators of the current status of the National Airspace System. This report has both described NAOMS's limitations sufficiently to enable others to look at redesigning them and suggested ways in which a newly undertaken project might successfully go forward. The planners and designers of a new survey might want to supplement it where NAOMS was self-limiting, by incorporating research into investigatory questions of the type that interested FAA, or to more specifically detail its monitoring capacity in conjunction with existing aviation safety systems. Alternatively, a newly constituted research team might lead operational, survey, and statistical experts in extensively analyzing existing data to validate a new survey's utility for various purposes or to illuminate future projects of the same type.
Language:
English

60-01 DIGITAL AND ANALOG COMPUTERS
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

61-01 COMPUTER SOFTWARE
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Generating Safety-Critical PLC Code From a High-Level Application Software Specification
Document ID:
20090022231
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 116-117
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States)
Pages:
2
Contract #:
None
Abstract:
The benefits of automatic-application code generation are widely accepted within the software engineering community. These benefits include raised abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at Kennedy Space Center recognized the need for PLC code generation while developing the new ground checkout and launch processing system, called the Launch Control System (LCS). Engineers developed a process and a prototype software tool that automatically translates a high-level representation or specification of application software into ladder logic that executes on a PLC. All the computer hardware in the LCS is planned to be commercial off the shelf (COTS), including industrial controllers or PLCs that are connected to the sensors and end items out in the field. Most of the software in LCS is also planned to be COTS, with only small adapter software modules that must be developed in order to interface between the various COTS software products. A domain-specific language (DSL) is a programming language designed to perform tasks and to solve problems in a particular domain, such as ground processing of launch vehicles. The LCS engineers created a DSL for developing test sequences of ground checkout and launch operations of future launch vehicle and spacecraft elements, and they are developing a tabular specification format that uses the DSL keywords and functions familiar to the ground and flight system users. The tabular specification format, or tabular spec, allows most ground and flight system users to document how the application software is intended to function and requires little or no software programming knowledge or experience. A small sample from a prototype tabular spec application is shown.
Language:
English

Title:
Hail Size Distribution Mapping
Document ID:
20090022237
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 52-53
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States)
Pages:
2
Contract #:
None
Abstract:
A 3-D weather radar visualization software program was developed and implemented as part of an experimental Launch Pad 39 Hail Monitor System. 3DRadPlot, a radar plotting program, is one of several software modules that form building blocks of the hail data processing and analysis system (the complete software processing system under development). The spatial and temporal mapping algorithms were originally developed through research at the University of Central Florida, funded by NASA s Tropical Rainfall Measurement Mission (TRMM), where the goal was to merge National Weather Service (NWS) Next-Generation Weather Radar (NEXRAD) volume reflectivity data with drop size distribution data acquired from a cluster of raindrop disdrometers. In this current work, we adapted these algorithms to process data from a cluster of hail disdrometers positioned around Launch Pads 39A or 39B, along with the corresponding NWS radar data. Radar data from all NWS NEXRAD sites is archived at the National Climatic Data Center (NCDC). That data can be readily accessed at <http://www.ncdc.noaa.gov /nexradin/>. 3DRadPlot plots Level III reflectivity data at four scan elevations (this software is available at Open Channel Software, <http://www.openchannelfoundation.org/projects/3DRadPlot>). By using spatial and temporal interpolation/extrapolation based on hydrometeor fall dynamics, we can merge the hail disdrometer array data coupled with local Weather Surveillance Radar-1988, Doppler (WSR-88D) radial velocity and reflectivity data into a 4-D (3-D space and time) picture of hail size distributions. Hail flux maps can then be generated and used for damage prediction and assessment over specific surfaces corresponding to structures within the disdrometer array volume. Immediately following a hail storm, specific damage areas and degree of damage can be identified for inspection crews.
Language:
English

Title:
Systems Maintenance Automated Repair Tasks (SMART)
Document ID:
20090022251
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 104-105
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) United Space Alliance (United States)
Pages:
2
Contract #:
None
Abstract:
SMART is an interactive decision analysis and refinement software system that uses evaluation criteria for discrepant conditions to automatically provide and populate a document/procedure with predefined steps necessary to repair a discrepancy safely, effectively, and efficiently. SMART can store the tacit (corporate) knowledge merging the hardware specification requirements with the actual "how to" repair methods, sequences, and required equipment, all within a user-friendly interface. Besides helping organizations retain repair knowledge in streamlined procedures and sequences, SMART can also help them in saving processing time and expense, increasing productivity, improving quality, and adhering more closely to safety and other guidelines. Though SMART was developed for Space Shuttle applications, its interface is easily adaptable to any hardware that can be broken down by component, subcomponent, discrepancy, and repair.
Language:
English

Title:
Some Improvements in Utilization of Flash Memory Devices
Document ID:
20090022334
Report #:
MSC-23465-1/6-1
Available Online:
http://www.techbriefs.com/component/content/article/5276
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Gender, Thomas K. (Honeywell, Inc.) Chow, James (Honeywell, Inc.) Ott, William E. (Honeywell, Inc.)
Journal:
NASA Tech Briefs, June 2009, Page: 16
Published:
20090601
Source:
Honeywell, Inc. (Houston, TX, United States)
Pages:
1
Contract #:
None
Abstract:
Two developments improve the utilization of flash memory devices in the face of the following limitations: (1) a flash write element (page) differs in size from a flash erase element (block), (2) a block must be erased before its is rewritten, (3) lifetime of a flash memory is typically limited to about 1,000,000 erases, (4) as many as 2 percent of the blocks of a given device may fail before the expected end of its life, and (5) to ensure reliability of reading and writing, power must not be interrupted during minimum specified reading and writing times. The first development comprises interrelated software components that regulate reading, writing, and erasure operations to minimize migration of data and unevenness in wear; perform erasures during idle times; quickly make erased blocks available for writing; detect and report failed blocks; maintain the overall state of a flash memory to satisfy real-time performance requirements; and detect and initialize a new flash memory device. The second development is a combination of hardware and software that senses the failure of a main power supply and draws power from a capacitive storage circuit designed to hold enough energy to sustain operation until reading or writing is completed.
Language:
English

Title:
Converting CSV Files to RKSML Files
Document ID:
20090022343
Report #:
NPO-45013
Available Online:
http://www.techbriefs.com/component/content/article/5289
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
Trebi-Ollennu, Ashitey (Jet Propulsion Lab., California Inst. of Tech.) Liebersbach, Robert (Jet Propulsion Lab., California Inst. of Tech.)
Journal:
NASA Tech Briefs, June 2009, Page: 25
Published:
20090601
Source:
Jet Propulsion Lab., California Inst. of Tech. (Pasadena, CA, United States)
Pages:
1
Contract #:
None
Abstract:
A computer program converts, into a format suitable for processing on Earth, files of downlinked telemetric data pertaining to the operation of the Instrument Deployment Device (IDD), which is a robot arm on either of the Mars Explorer Rovers (MERs). The raw downlinked data files are in comma-separated- value (CSV) format. The present program converts the files into Rover Kinematics State Markup Language (RKSML), which is an Extensible Markup Language (XML) format that facilitates representation of operations of the IDD and enables analysis of the operations by means of the Rover Sequencing Validation Program (RSVP), which is used to build sequences of commanded operations for the MERs. After conversion by means of the present program, the downlinked data can be processed by RSVP, enabling the MER downlink operations team to play back the actual IDD activity represented by the telemetric data against the planned IDD activity. Thus, the present program enhances the diagnosis of anomalies that manifest themselves as differences between actual and planned IDD activities.
Language:
English

Title:
Evaluation of Material Models within LS-DYNA(Registered TradeMark) for a Kevlar/Epoxy Composite Honeycomb
Document ID:
20090022372
Report #:
LF99-7613
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Polanco, Michael A. (ATK Space) Kellas, Sotiris (NASA Langley Research Center) Jackson, Karen (NASA Langley Research Center)
Published:
20090527
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
16
Contract #:
None
Abstract:
The performance of material models to simulate a novel composite honeycomb Deployable Energy Absorber (DEA) was evaluated using the nonlinear explicit dynamic finite element code LS-DYNA(Registered TradeMark). Prototypes of the DEA concept were manufactured using a Kevlar/Epoxy composite material in which the fibers are oriented at +/-45 degrees with respect to the loading axis. The development of the DEA has included laboratory tests at subcomponent and component levels such as three-point bend testing of single hexagonal cells, dynamic crush testing of single multi-cell components, and impact testing of a full-scale fuselage section fitted with a system of DEA components onto multi-terrain environments. Due to the thin nature of the cell walls, the DEA was modeled using shell elements. In an attempt to simulate the dynamic response of the DEA, it was first represented using *MAT_LAMINATED_COMPOSITE_FABRIC, or *MAT_58, in LS-DYNA. Values for each parameter within the material model were generated such that an in-plane isotropic configuration for the DEA material was assumed. Analytical predictions showed that the load-deflection behavior of a single-cell during three-point bending was within the range of test data, but predicted the DEA crush response to be very stiff. In addition, a *MAT_PIECEWISE_LINEAR_PLASTICITY, or *MAT_24, material model in LS-DYNA was developed, which represented the Kevlar/Epoxy composite as an isotropic elastic-plastic material with input from +/-45 degrees tensile coupon data. The predicted crush response matched that of the test and localized folding patterns of the DEA were captured under compression, but the model failed to predict the single-cell three-point bending response.
Language:
English
Notes:
AHS International 65th Forum and Technology Display Grapevine, TX 27-29 May 2009

61-02 CAD/CAM
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Concept of Operations Visualization in Support of Ares I Production
Document ID:
20090022312
Report #:
MSFC-2103-2
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Chilton, James H. (Boeing Aerospace Co.) Smith, Daid Alan (Boeing Aerospace Co.)
Published:
20081003
Source:
Boeing Aerospace Co. (Huntsville, AL, United States)
Pages:
11
Contract #:
NNM07AB03C
Abstract:
Boeing was selected in 2007 to manufacture Ares I Upper Stage and Instrument Unit according to NASA's design which would require the use of the latest manufacturing and integration processes to meet NASA budget and schedule targets. Past production experience has established that the majority of the life cycle cost is established during the initial design process. Concept of Operations (CONOPs) visualizations/simulations help to reduce life cycle cost during the early design stage. Production and operation visualizations can reduce tooling, factory capacity, safety, and build process risks while spreading program support across government, academic, media and public constituencies. The NASA/Boeing production visualization (DELMIA; Digital Enterprise Lean Manufacturing Interactive Application) promotes timely, concurrent and collaborative producibility analysis (Boeing)while supporting Upper Stage Design Cycles (NASA). The DELMIA CONOPs visualization reduced overall Upper Stage production flow time at the manufacturing facility by over 100 man-days to 312.5 man-days and helped to identify technical access issues. The NASA/Boeing Interactive Concept of Operations (ICON) provides interactive access to Ares using real mission parameters, allows users to configure the mission which encourages ownership and identifies areas for improvement, allows mission operations or spacecraft detail to be added as needed, and provides an effective, low coast advocacy, outreach and education tool.
Language:
English
Notes:
59th International Astronautical Conference/International Astronautical Federation Glasgow, Scotland 29 Sep. - 4 Oct. 2008

63-01 CYBERNETICS AND BIONICS
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

63-02 ARTIFICIAL INTELLIGENCE
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

64-01 NUMERICAL ANALYSIS
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Reliability-Based Design Optimization of a Composite Airframe Component
Document ID:
20090022184
Report #:
NASA/TM-2009-215501, AIAA Paper 2008-5879, E-16553-1
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Patnaik, Surya N. (Ohio Aerospace Inst.) Pai, Shantaram S. (NASA Glenn Research Center) Coroneos, Rula M. (NASA Glenn Research Center)
Published:
20090401
Source:
Ohio Aerospace Inst. (Brook Park, OH, United States)
Pages:
35
Contract #:
None
Abstract:
A stochastic design optimization methodology (SDO) has been developed to design components of an airframe structure that can be made of metallic and composite materials. The design is obtained as a function of the risk level, or reliability, p. The design method treats uncertainties in load, strength, and material properties as distribution functions, which are defined with mean values and standard deviations. A design constraint or a failure mode is specified as a function of reliability p. Solution to stochastic optimization yields the weight of a structure as a function of reliability p. Optimum weight versus reliability p traced out an inverted-S-shaped graph. The center of the inverted-S graph corresponded to 50 percent (p = 0.5) probability of success. A heavy design with weight approaching infinity could be produced for a near-zero rate of failure that corresponds to unity for reliability p (or p = 1). Weight can be reduced to a small value for the most failure-prone design with a reliability that approaches zero (p = 0). Reliability can be changed for different components of an airframe structure. For example, the landing gear can be designed for a very high reliability, whereas it can be reduced to a small extent for a raked wingtip. The SDO capability is obtained by combining three codes: (1) The MSC/Nastran code was the deterministic analysis tool, (2) The fast probabilistic integrator, or the FPI module of the NESSUS software, was the probabilistic calculator, and (3) NASA Glenn Research Center s optimization testbed CometBoards became the optimizer. The SDO capability requires a finite element structural model, a material model, a load model, and a design model. The stochastic optimization concept is illustrated considering an academic example and a real-life raked wingtip structure of the Boeing 767-400 extended range airliner made of metallic and composite materials.
Language:
English
Notes:
12th Multidisciplinary Analysis and Optimization Conference British Columbia 10 - 12 Sep. 2008

Title:
Numerical Analysis of Rocket Exhaust Cratering
Document ID:
20090022209
Report #:
None
Sales Agency:
CASI Hardcopy A01 Copyright
Author(s):
(Author(s) Not Available)
Journal:
John F. Kennedy Space Center's Technology Development and Application 2006-2007 Report, Page: 34-35
Published:
20080303
Source:
NASA Kennedy Space Center (Cocoa Beach, FL, United States) Florida Inst. of Tech. (FL, United States)
Pages:
2
Contract #:
None
Abstract:
Supersonic jet exhaust impinging onto a flat surface is a fundamental flow encountered in space or with a missile launch vehicle system. The flow is important because it can endanger launch operations. The purpose of this study is to evaluate the effect of a landing rocket s exhaust on soils. From numerical simulations and analysis, we developed characteristic expressions and curves, which we can use, along with rocket nozzle performance, to predict cratering effects during a soft-soil landing. We conducted a series of multiphase flow simulations with two phases: exhaust gas and sand particles. The main objective of the simulation was to obtain the numerical results as close to the experimental results as possible. After several simulating test runs, the results showed that packing limit and the angle of internal friction are the two critical and dominant factors in the simulations.
Language:
English

65-01 PROBABILITY AND STATISTICS
Jun 28, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
External Tank Liquid Hydrogen (LH2) Prepress Regression Analysis Independent Review Technical Consultation Report
Document ID:
20090022321
Report #:
NASA/TM-2009-215745, NESC-RP-06-01/05-171-E, L-19680, LF99-8837
Available Online:
http://hdl.handle.net/2060/20090022321
Sales Agency:
CASI Hardcopy A03 No Copyright
Author(s):
Parsons, Vickie s. (NASA Langley Research Center)
Published:
20090501
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
39
Contract #:
None
Abstract:
The request to conduct an independent review of regression models, developed for determining the expected Launch Commit Criteria (LCC) External Tank (ET)-04 cycle count for the Space Shuttle ET tanking process, was submitted to the NASA Engineering and Safety Center NESC on September 20, 2005. The NESC team performed an independent review of regression models documented in Prepress Regression Analysis, Tom Clark and Angela Krenn, 10/27/05. This consultation consisted of a peer review by statistical experts of the proposed regression models provided in the Prepress Regression Analysis. This document is the consultation's final report.
Language:
English

Title:
New Method for Updating Mean Time Between Failure for ISS Orbital Replaceable Units Consultation Report
Document ID:
20090022322
Report #:
NASA/TM-2009-215746, NESC-RP-05-131/05-163-E, L-19681, LF99-8838
Available Online:
http://hdl.handle.net/2060/20090022322
Sales Agency:
CASI Hardcopy A03 No Copyright
Author(s):
Parsons, Vickie S. (NASA Langley Research Center)
Published:
20090501
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
30
Contract #:
None
Abstract:
A request to conduct a peer review of the International Space Station (ISS) proposal to use Bayesian methodology for updating Mean Time Between Failure (MTBF) for ISS Orbital Replaceable Units (ORU) was submitted to the NASA Engineering and Safety Center (NESC) on September 20, 2005. The results were requested by October 20, 2005 in order to be available during the process of reworking the current ISS flight manifest. The results are included in this report.
Language:
English