NDTech Newsletter #13

Lightweight Inspection Crawling Apparatus

The multifunction automated crawling system (MACS) is a relatively compact, lightweight apparatus utilizing suction cups to crawl on aircraft and perform inspection tasks. The MACS functions in any orientation, including vertical or upside-down. Under remote control or onboard computer control, the MACS can be maneuvered so that the equipment that it carries can inspect aircraft and marine structures for such defects as dents, cracks, corrosion, impact damage, delamination, fire damage, and porosity. The MACS could also perform such other tasks as removing paint and carrying hazardous materials.

The MACS includes a platform, on which are mounted two piezoelectricmotor-driven legs; a U-shaped outer leg and a round inner leg. Both legs are equipped with suction cups (see figure) to grip the surface on which the MACS crawls. A miniature onboard computer coordinates the operations of the suction cups and legs. For example, initially, the cups on the inner leg are evacuated and extended to the surface to grip the surface, while the cups on the

outer leg are not evacuated and are withdrawn from the surface so that the outer leg is free to move. The outer leg is then translated to the next step position. When necessary, the platform can also be rotated on the inner leg to change the direction of translation and/or orient the platform for a specific task. Next, the cups on the outer leg are extended toward the surface and evacuated, air is admitted to the cups on the inner leg to release their grip, these cups are withdrawn from the surface, and the inner leg is translated so that it catches up with the outer leg. The cycle is then repeated.

The partial vacuums in the cups are produced by small venturi pumps that operate on shop compressed air, which is usually available at pressures from 70 to 120 psi (0.48 to 0.83 MPa). Each cup is connected to a separate pump, so that if one cup loses vacuum on a rough surface, the others on the leg still grip the surface. The same supply of compressed air used to generate suction is also used to extend the suction cups toward the surface for gripping.

The platform can carry any of a variety of modules; for example, a video camera for visual inspection, ultrasonic or eddy-current instrumentation to detect invisible flaws, or a source of heat to remove paint. The MACS weighs about 10 lb (4.5 kg) and can carry payloads weighing up to about 100 lb (45 kg).

This work was done by Yoseph Bar-Cohen, Benjamin Joffe, and Paul Backes of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free online at http://www.nasatech.com under the Machinery/Automation category, or circle no. 156 on the TSP Order card in this issue to receive a copy by mail (US$5 charge).

In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:

Larry Gilbert, Director

Technology Transfer

California Institute of Technology

Mail Code 315-6

Pasadena, CA 91125

(818) 395-3288

Refer to NPO-19847, volume and number of this NASA Tech Briefs issue, and the page number.

Robot Would Inspect Hanging Cables

A proposed automated apparatus would travel along a hanging cable, optically inspecting it all around. The proposal was made to eliminate lowering human inspectors in baskets along emergency-egress slidewires at Kennedy Space Center launch pads. The apparatus would include a motor drive system, a video camera configured with mirrors for a 36O view of the cable, a data-capturing system, a laser micrometer, a video transmitter, and a radio transceiver for command and data signals. The apparatus would be placed on a cable at one end, then the inspection process would be initiated. During the process, the apparatus would operate under the control of a compact, rugged, onboard computer. Upon reaching the far end of the cable, the apparatus would automatically reverse itself and return to the starting end. An electronic neural network could be used, either on board the apparatus or in the command station, to analyze the inspection data to determine the integrity of the cable.

This work was done by Robert L. Morrison, Kenneth M. Nowak, Terencef Ross, Eduardo Lopez del Castillo, Michael D. Hogue, and Tom Bonner of and Gabor Tamasi formerly of Kennedy Space Center.

This invention is owned by NASA, and a patent application has been filed. Inquiries concerning nonexclusive or exclusive license for its commercial development should be addressed to the Technology Programs and Commercialization Office, Kennedy Space Center (407) 867-6373, or for information regarding commercially available application of this technology contact: Halkin International at Halkinl@aol.com or telephone (303) 344-9592 (a nonexclusive licensee).

Refer to KSC-12023.

Verifying Removal of Red Penetrant Dye From Inspected Welds

A simple procedure has been devised to ensure that visible (red) penetrant dye that has been used to identify flaws in a welded surface has been completely removed from the surface. It is necessary to ensure complete removal because any residual red dye could interfere with a subsequent inspection in which ultraviolet illumination and a fluorescent penetrant dye are used to identify smaller defects.

The procedure consists in applying a reversible penetrant developer to the surface to be inspected. The developer contains a fluorescent dye that reacts with, and thus is eliminated by, the red penetrant dye. Therefore, when the surface is viewed under ultraviolet illumination, the residual spots of red penetrant dye stand out as dark spots against a fluorescent background. Once the removal of red penetrant dye has been completed and verified by this procedure, the developer is removed from the surface by rinsing with water.

This work was done by Jan R. Torkelson of Rockwell International Corp. for Marshall Space Flight Center. For further information, call 205.544.0021 referring to MFS-30001

NTIAC Publications

As a national resource of nondestructive evaluation, inspection, and testing technology, NTIAC provides rapid response to inquiries, especially where field and military systems are involved, or where failure may occur. NTIAC specializes in all aspects of nondestructive evaluation (NDE), inspection, and testing. From process control to life extension, NTIAC applies NDE technologies in the broadest possible sense.

Nondestructive techniques utilize noninvasive methods and processes involving material-energy interaction to detect flaws and/or to characterize a material, component, or entire system. NDE data can be used to reliably predict performance under a prescribed service regime.

NTIAC's scope includes radiographic, acoustic, ultrasonic, magnetic, thermal, and other methods; use of nondestructive sensors for process, and/or adaptive, control; economic aspects of NDE; industry trends; NDE research and development, production, maintenance, and safety monitoring; failure prevention of in-service material; and life assurance.

For further information, or to order materials, contact NTIAC at:

NTIAC

415 Crystal Creek Drive

Austin, TX 78746

Phone: (512) 263-2106 (800) NTIAC 39

Fax: (512) 263-3530

Email: ntiac@access.texas.gov

Website: http://www.dtic.dIa.miI/iac/ntiac/ntiachome.html

NDT Standards and Specifications Database

This database contains information on over 1500 NDT related standards, specifications, recommended practices and requirements from more than 40 sources, including ASTM, Government and Foreign organizations.

Each record contains title, source organization, issue date, revision date, NDT method, document number, and keywords. Most records also include an abstract of the document's content. Searches can be performed by keyword, source organization, title, document number, and abstract text string.

A floppy disk containing the complete NDT Standards and Specifications Database along with a user's manual, can be purchased for $150. Bi-annual updates are available at a cost of $50 per year. This program operates in DOS, and requires a minimum of a 286 computer, 2 MB RAM and 5 MB of hard drive memory. No separate database software is needed to run the program.

Hard copy search results from the database can also be purchased for a search fee of $20 plus $1 per record.

For further information, or to order materials, contact NTIAC at:

NTIAC

415 Crystal Creek Drive

Austin, TX 78746

Phone: (512) 263-2106 (800) NTIAC 39

Fax: (512) 263-3530

Email: ntiac@access.texas.gov

Website: http://www.dtic.dIa.miI/iac/ntiac/ntiachome.html

Nondestructive Evaluation (NDE) Capabilities Databook

This Data Book consolidates and organizes available reference data for demonstrated NDE performance capabilities into a single source. Data generated and documented in various forms over the past 25 years through a number of government and private programs have been analyzed, organized and presented in a systematic, common format. . and ~. Guidelines are presented for selecting options for use of NDE and for assessing the potential to meet design requirements (critical flaw detection requirements). Guidelines for demon-stration of specific NDE process capabilities are also presented.

Following a 65 page text (7 chapters) describing various aspects of NDE capabilities quantification, probability of detection (POD), and damage tolerance concepts, 229 POD curves are organized and presented in a series of Appendices. The Appendices are organized by NDE method to provide reference POD data; NDE procedure capabilities included in the Data Book are:

ET - Eddy Current Inspection MT - Magnetic Particle Inspection

UT - Ultrasonic Inspection VT - Visual Inspection

RT - X-Radiographic Inspection ZT - Emerging Inspection Processes

PT - Liquid Penetrant Inspection (visible and fluorescent)

A documentation page precedes each data-set and provides a condensed description of the test object, test artifacts, NDE procedures and results summary. The POD curves for varying test object, test artifact and data collection conditions follow the documentation page: POD data are presented as a function of crack length, and as a function of crack depth and crack depth-to-thickness ratio for selected data sets. Original reference source information is provided for each data set. Materials covered include: aluminum (2219 T-87 and 2024 T-37), stainless steel (AMS 355), and titanium-6A14V.

The NDE Capabilities Data Book (publication number NTIAC DB-95-02) is available in hard copy from NTIAC for $100 ($1 10 overseas). A three-ring binder format is utilized to provide flexibility for updating the Data Book as new NDE data are generated and made available. Raw data used in developing the Data Book are archived in both hard copy and electronic form and can be provided for additional cost.

For further information, or to order materials, contact NTIAC at:

NTIAC

415 Crystal Creek Drive

Austin, TX 78746

Phone: (512) 263-2106 (800) NTIAC 39

Fax: (512) 263-3530

Email: ntiac@access.texas.gov

Website: http://www.dtic.dIa.miI/iac/ntiac/ntiachome.html

Nondestructive Testing Products and Services Database

This database contains information on over 7,500 companies and organizations worldwide that provide NDT products, services, instruments, equipment, supplies, and accessories. The database can be searched by company name, geographic area (city, state, country, zip code, etc.), NDT method, products and services provided, or trade names.

Upon request, NTIAC will perform searches of the Products and Services Database for a charge of $50 for up to 100 "hits" plus $1 for each "hit" over the first 100. Results can be provided in hard copy or floppy disk format and include company name, address, phone and fax numbers, contact persons, and products and services provided (individual records may not contain information in all of these fields).

For further information, or to order materials, contact NTIAC at:

NTIAC

415 Crystal Creek Drive

Austin, TX 78746

Phone: (512) 263-2106 (800) NTIAC 39

Fax: (512) 263-3530

Email: ntiac@access.texas.gov

Website: http://www.dtic.dIa.miI/iac/ntiac/ntiachome.html

1999 USAF Aircraft Structural Integrity Program (ASIP) Conference

The 1999 ASIP Conference is sponsored by the Materials and Manufacturing Directorate and the Air Vehicles Directorate of the Air Force Research Laboratory and Deputy for Engineering, Aeronautical systems Center, Wright-Patterson Air Force Base, Ohio. It is co-sponsored by the San Antonio Air Logistics Center's Fighter/Trainer Directorate at Kelly Air Force Base, San Antonio, Texas. This conference is intended to bring together world leaders in the area of aircraft structural integrity and associated technologies to exchange information on the latest developments in the design and acquisition of new aircraft systems and the maintenance of aging aircraft systems in both military and commercial fleets. Attendance for this internationally recognized conference is unclassified /unlimited and open. A large number of well-qualified foreign nationals attend this conference, bringing a broad perspective to the technology being discussed.

For more information, contact Dr. Jack Lincoln, ASC /EN, WPAFB, OH at (937) 656-4546 or Universal Technology Corporation (UTC) at (937) 426-2808 and ask for the 1999 USAF Aircraft Structural Integrity Program Conference Desk.

Fax: (937)426-8755.

Website: http://www.asipcon.com

Publications

Review of Progress in Quantitative Nondestructive Evaluation: Volumes 18A and 18B - Donald 0. Thompson and Dale E. Chimenti. This series provides a comprehensive review of the latest research results in quantitative nondestructive evaluation (NDE). Leading investigators working in government agencies, major industries, and universities present a broad spectrum of work extending from basic research to early engineering applications. An international assembly of noted authorities in NDE thoroughly cover such topics as: elastic waves, guided waves, and eddy-current detection, inversion, and modeling; radiography and computed tomography, thermal techniques, and acoustic emission; laser ultrasonics, optical methods, and microwaves; signal processing and image analysis and reconstruction, with an emphasis on interpretation for defect detection; and NDE sensors and fields, both ultrasonic and electromagnetic; engineered materials and composites, bonded joints, pipes, tubing, and biomedical materials; linear and nonlinear properties, ultrasonic backscatter and microstructure, coatings and layers, residual stress and texture, and construction materials; new inspection procedures, process control, and probability of detection.

This book will be of interest to investigators in the fields of materials science and engineering, ceramics and glass science, electronic materials and devices, and instrument engineering.

This summary as well as the book can be found at www.amazon.com. The book is listed at $425.00 and has 2,464 pages. It was published in May 1999.

Nondestructive and Automated Testing for Soil and Rock Properties &emdash; W. Allen Marr (editor) and Charles Fairhust (editor) (American Society for Testing and Materials publication STP-1350). The first publication of its kind to feature state-of-the-art research on economical and timely ways to evaluate a wide range of soil and rock characteristics. Twenty comprehensive peer-reviewed papers are divided into the following key areas:

• Nondestructive Testing Methods in the Laboratory&emdash;Evaluation techniques including X-ray absorption, medical imaging, active and passive acoustic imaging, and the environmental scanning electron microscope.

• Nondestructive Testing in the Field&emdash;Test methods such as time-domain reflectometry, surface wave measurement and modeling in drilled rock shafts, and construction induced vibrations.

• Automated Testing&emdash;In addition to a survey of geotechnical laboratory automation practices and actual experience with automated geotechnical testing, such topics as direct shear testing, modeling pre-failure stress-strain properties, and the use of an automated triaxial apparatus.

This summary as well as the book can be found at http://www.astm.org. This is listed at $82.00 in North America, $90.00 elsewhere and has 325 pages. It was published in July 1999.

Patents

- On August 24,1999 the United States Navy was issued Patent #5,942,687:

Method and apparatus for in situ measurement of corrosion in filled tanks. The inventors are Kirth E. Simmonds, Narendra K. Batra, and Richard B. Mignogna. This apparatus allows for the inspection of the base of a liquid-filled tank using ultrasonic pulses.

- On August 24,1999 the United States Navy was issued Patent #5,942,748:

Liquid level sensor and detector. The inventors are Stephen D. Russell and Wadad B. Dubbelday. This system allows for the detection of luminescence caused by a fluid in contact with a light emitting photonic structure with a transparent substrate.

- On July 27, 1999 the United States Army was issued Patent #5,929,338:

Thickness measurement of in-ground culverts. The inventors are Julius Frankel, Agostino Abbate, and Stephan C. Schroeder. This system enables the continuous, intermittent, or remote command measurement of the thickness changes of underground culverts under variable temperature changes, whether above or below the water.

- On July 13, 1999 the United States Department of Commerce was issued Patent #5,922,961: Time and polarization resolved acoustic microscope. The inventors are Nelson N. Hsu, Dan Xiang, and Gerald V. Blessing. The new system provides for analysis of an olid sample with fluid coupling.

- On June 1, 1999 the United States Navy was issued Patent #5,909,409:

Method and apparatus for underwater acoustic detection and )location of an object. The inventors are Lewie M. Barber, Bernie R. Criswell, Allen G. Findelsen, and Benjamin F. L. Weiss. This method utilizes an underwater combination of passive and active acoustics to detect and locate a surfaced or submerged object or target.

- On April 20, 1999 the United States Air Force was issued Patent #5,895,927: Electro-optic, noncontact, interior cross-sectional profiler. The inventor is Jeff Lee Brown. This probe is used to determine the physical characteristics of an interior surface of a tubular structure.

- On April 20, 1999 the United States Department of Commerce was issued Patent #5,895,856: Electromagnetic acoustic transducer and methods of determining physical properties of cylindrical bodies using an electromagnetic acoustic transducer. The inventors are Ward L. Johnson, George A. Alers, and Bertram A. Auld. A transducer is used to induce and sense vibrations and determine the resonant frequencies and physical properties in cylindrical objects.

Meetings and Symposia Calendar

Nov 22-26: NDTISS '99: International Symposium on Nondestructive Testing's Contribution to the Infrastructure Safety Systems in the 21st Century, Torrs, RS, Brazil. Contact: Edouard G. Nesvijski, Organizing Committee NDTISS '99, Center of Technology, Federal University of Santa Maria (UFSM), Campus Universitario, 97105-900, Santa Maria, Brazil. Fax:

(055) 226-2166. Email: ndtiss@ct.ufsmbr

Nov 29-Dec 3: Symposium on Nondestructive Methods for Materials Characterization, Hynes Convention Center and Boston Marnott Copley Place, Boston, MA. Contact: MRS Headquarters, 506 Keystone Drive, Warrendale, PA 15086-7573. Phone: (724) 779-3003. Fax: (724) 779-3030. Website: www.mrs.org

Nov 30-Dec 2: U.S. Air Force Aircraft Structural Integrity Program (ASIP) Conference, Hyatt Regency San Antonio Hotel, San Antonio,

TX. Contact: Dr. Jack Lincoln, ASC/EN, WPAFB, OH at (937)255-5312, fax: (937) 656-4546 or the 1999 USAF Aircraft

Structural Integrity Program Conference Desk at Universal Technology Corporation (UTC) at (937) 426-2808, fax: (937)

426-8755. Website: http://www.asipcon.com

New to the Web

Free science database from the DOE

The Dept. of Energy's Office of Scientific and Technical Information, Oak Ridge, Tenn., has just made available the first version of PubSCIENCE, a comprehensive new database of papers in the physical sciences. The database offers searchable free Internet access to titles, authors, and abstracts from hundreds of journals. Once the user locates an abstract of interest, a hyperlink provides access to the publisher's server to obtain the full article text.

http://pubsci.osti.gov

Manufacturing Marketplace provides a portal to the industrial news, shopping, classifieds, and links to dozens of trade magazines.

http://www.manufacturing.net

Invention web site from MIT provides information on inventions, hosts an "inventor of the week" competition, and lists dozens of useful links.

http://web.mit.edu/invent/

The US Patent and Trademark Office site contains a searchable database of patents and trademarks, as well as guides to filing patents and relevant forms in PDF format.

http://www.uspto.gov

The collection of links by Sansalone Process Engineering Language Services include dictionaries for process engineers, international patent materials, and useful sites for researchers in chemistry, physics, semiconductors, vacuum/thin film, and more. http://www.sansalone.de/engl/links.htm

Web program helps manufacturers

A new web tool called Manufacturing Efficiency Decision Support (MEDS) can help manufacturers compare and evaluate manufacturing technologies. MEDS can provide users with information on performance, cost, energy, and environmental implications of more than 175 technologies in areas such as fabricated metals, plastics, and electronics. The tool provides background information, economic and technical feasibility, case studies, and vendor information. MEDS also allows users to conduct "what if" analyses by altering variables, such as budget constraints. The Michigan Manufacturing Technology Center developed MEDS with funding from the National Institute of Standards and Technology.

http://meds.mmtc.org