The Defense Advanced Research Projects Agency awarded $1.7 million in funding to SwRI to develop a novel, wireless, sensor system for crack detection and monitoring in critical turbine engine components. The award is part of the technology development phase of DARPA's Prognosis program, which aims to provide field commanders with the ability to forecast, adaptively manage and use high-value military assets to the limits of their current capability.
Sensors for monitoring the damage state of turbine engine components are crucial to forecasting remaining life and managing assets in the field. Current indirect methods of crack sensing by monitoring the dynamic response of turbine shaft and blade-tip displacements have limited reliability for crack detection. Direct monitoring of cracks in turbine discs is hampered by the harsh thermal and stress environment of a jet engine.
"Our goal is to create smart materials that are capable of sensing their own state of damage using distributed thin-film magnetostrictive sensors integrated onto a component's surface near fracture-critical locations," said Program Manager Dr. Stephen Hudak, an Institute scientist in SwRI's Mechanical and Materials Engineering Division.
Ultrasonic waves will be periodically injected into the component to detect cracks by sensing the back-scattered waves reflected from the defect. A thin-film antenna embedded in the material will harvest energy beamed from outside the engine to power sensor activation and radio frequency (RF) communication.
"Our concept is analogous to human skin. When damage occurs, a message is transmitted to the brain and the body reacts to it. This smart skin, applied to a turbine component, will signal information about its damage," Hudak said.
SwRI researchers are taking a multidisciplinary approach to developing the system and will integrate Institute capabilities in materials science, surface engineering, RF communication and magnetostrictive sensor technology, of which the Institute is a pioneer. SwRI is also working with turbine engine manufacturers to ensure technology transfer.
"The first phase of the project will be devoted to developing new sensing materials that are very thin, a few microns or less, and then demonstrating that we can produce elastic waves with these films. At the same time, another group of Institute engineers will be developing the antenna and RF communications," Hudak said.
Temperatures in turbine engines can run from 600 degrees F in the front of the engine to 1,400 degrees F or more in the back, or "hot section" of the engine. These extreme temperatures, coupled with the high stress conditions during turbine operation, demand materials that can withstand a harsh environment.
"This is a challenging program, but if we can get this system to work in a turbine engine environment we can get it to work in many other environments. These sensor systems could be applied to airframes, helicopters, ships - they may revolutionize how we monitor critical components," Hudak added.
Phase I is expected to run until November 2005.
Contact Hudak at (210) 522-2330 or email@example.com.
The Chemistry and Chemical Engineering Division has achieved ISO 9001:2000 certification. Previously the division was ISO 9002 certified. ISO certification is a set of international standards used to certify a quality system for the development of products, starting with the initial design through production and servicing.
All four departments: Analytical and Environmental Chemistry; Environmental and Demilitarization Technology; Nanomaterials, Microencapsulation, and Process Engineering; and Fire Technology are ISO certified.
The division was audited in August 2003 and recommended for certification in October 2003.
The NSF International Strategic Registration (NSF-ISR) Ltd., audited the division and issued the certification. The NSF-ISR carries more than 50 years of auditing and certification experience.
The Fire Technology Department has also achieved ISO/IEC Standard 17020 and 17025 accreditation. The International Accreditation Service Inc., a subsidiary corporation of the International Code Council, certified the department as a testing laboratory and inspection agency.
ISO/IEC Standard 17020 certifies that the department has met "general criteria for the operation of various types of bodies performing inspections," including requirements from the ISO 9000 series. As a third-party inspection agency, the department can inspect door assemblies, windows, and door frames; foam plastic insulation products; prefabricated structural and non-structural panels; roof coverings and assemblies; interior finish materials; above-ground fuel storage tanks; and fire-resistive-rated walls, floors, and floor-to-ceiling and roof assemblies.
IAS certified that the Fire Technology Department met the criteria for ISO/IEC Standard 17025 testing and calibration laboratories for fire, physical and thermal transmission.
Contact Jo Ann Boyd at (210) 522-2169 or firstname.lastname@example.org.
SwRI engineers have developed a new tool for fast, precise measurement of corrosivity in crude oil using a proven technology for automotive wear testing.
The device uses a heated flow loop with an irradiated metal coupon inserted into the flowstream. Using gamma ray spectrometry, it detects and measures the buildup of radioactive corrosion products in the oil as it flows over the coupon. The oil sample can be heated to 650 degrees F and subjected to flow rates that simulate refinery operations.
"Buyers and sellers of crude oils whose chemical properties are unknown, sometimes referred to as opportunity crudes, can use this tool to make informed pricing decisions," said Martin B. Treuhaft, manager of the Filtration and Fine Particle Technology program within SwRI's Engine, Emissions and Vehicle Research Division. "Refiners also can use it to assess the corrosivity of a crude before it is refined."
Oil circulating in the flow loop is radiometrically monitored at 10-minute intervals to track rising radiation levels as the crude oil sample carries minute amounts of radioactive corrosion products from the coupon. The resulting trends are more precise, faster and more reliable than those obtained using existing methods.
The recirculating flow loop allows tests to be tailored for specific conditions of shear stress and temperature, resulting in measurements that are accurate, repeatable and highly sensitive.
A lower-cost alternative method, in which the crude sample is placed in a heated autoclave and agitated in the presence of an irradiated coupon, can yield corrosion values in as little as 1.5 hours, both for corrosion products dissolved in the oil and for corrosion that is mechanically removed from the coupon and measured separately.
Older, standard coupon weight-loss methods of measuring corrosivity take 24 to 48 hours and can be influenced by corrosion products adhering to the coupon and by degradation of the crude oil during long periods at elevated temperatures. Also, existing corrosivity indexes such as the total acid number may not be sufficient indicators of a crude stock's real potential to corrode the storage tanks, pipelines and refining equipment that contain, transport and process it.
SwRI drew on its long experience with radioactive tracer technology (RATT®) to develop the new tool. Previous RATT applications at SwRI have included measuring real-time wear in operating engines, pumps and other mechanical components, and in medical applications such as evaluation of materials used in hip joint components.
Contact Treuhaft at (210) 522-2626 or email@example.com.
SwRI engineers have developed the Multielectrode Array Sensor System (MASS) for real-time monitoring of localized corrosion in structures such as bridges and aircraft as well as in chemical plants, power plants and refineries.
Localized corrosion is one of the most common failure modes for engineering components. Corrosion often results in high rates of metal penetration and leads to premature component failure even though much of the metal surface may not be affected.
MASS uses multiple miniature electrodes composed of materials identical to the component being tested as the sensing electrode. The electrodes are coupled together by connecting each to a common joint through independent small resistors, with each electrode simulating part of a corroding metal.
In a localized corrosion environment, anodic current flows into the more corroding electrodes and cathodic current flows out of the less or non-corroding electrodes. These currents, measured from the voltage drop across the small resistors, are used as the signals for localized corrosion.
The system also includes an SwRI-developed multi-channel, high-resolution, voltage-measuring system and its associated software. The software has a graphical user interface for specifying the configuration of the measurement, including the mapping of electrode locations. During the measurement, the current values are stored in memory and displayed numerically and graphically.
"The Multielectrode Array Sensor System can be tailored to meet the process needs of a variety of industries," said Dr. Narasi Sridhar, a program manager in SwRI's Mechanical and Materials Engineering Division and a developer of the system. "Various prototypes have been fabricated using carbon steels, stainless steels and nickel-based alloys. These prototypes have successfully measured localized corrosion taking place under a number of simulated conditions including cooling water, concentrated chloride solutions, humid air and hygroscopic salt deposits."
The versatility of the system allows it to be a viable instrument to detect corrosion in such diverse structures as aircraft, natural gas pipelines, refineries, military equipment in corrosive environments, and offshore structures.
"The Multielectrode Array Sensor System is a significant improvement over existing technologies because the system is a sensitive indicator of localized corrosion, can detect formation of corrosive electrolytes and can measure localized corrosion rates. Additionally, it provides a real-time indication of localized corrosion," Sridhar said.
For more information visit corrosion.swri.org.
Dr. Kwai S. Chan, an Institute scientist in the Mechanical and Materials Engineering Division at Southwest Research Institute, has been elected a Fellow of the American Society of Mechanical Engineers (ASME) International.
The Fellow grade of membership is conferred upon an ASME member with at least 10 years of active engineering practice and recognizes exceptional engineering achievements and contributions to the engineering profession. Chan was cited for his contributions to the development of physics-based material degradation models for predicting the useful lives of structural alloys and high-temperature coatings in various engineering applications.
Chan came to SwRI in 1982 following post-doctoral research at Stanford University. A specialist in the mechanical behavior of materials, his current research interests are flow and fracture, micromechanical modeling of material behavior and development of life-prediction methodologies.
Much of his research for the last 15 years has concerned degradation mechanisms in high-temperature alloys such as Nb-based, in-situ compositions, TiAl aluminide, metallics and thermal barrier coatings.
Chan has received a number of awards for technical papers. In 2002, he received the Henry Marion Howe Medal from ASM (American Society for Metals) International and in 2001, the Champion H. Mathewson Medal from TMS (The Minerals, Metals and Materials Society).
Also, he is the 1991 recipient of the Alfred Noble Prize presented by the American Society of Civil Engineers, and has been honored three times as a young author, receiving the ASM Marcus A. Grossman Young Author Award in 1986 and 1994, and the Rossiter W. Raymond Memorial Award in 1990 from the American Institute of Mining, Metallurgical and Petroleum Engineers.
The author of more than 190 papers, Chan earned bachelor's, master's and doctoral degrees in metallurgical engineering from Michigan Technological University. He is a Fellow of ASM International and a member of TMS, American Society for the Advancement of Science, Sigma Xi and Alpha Sigma Mu.
Contact Chan at (210) 522-2053 or firstname.lastname@example.org.
John P. Hageman, a principal scientist and radiation safety officer at Southwest Research Institute, has been selected a Fellow of the Health Physics Society, a nonprofit scientific professional organization with a mission to promote the practice of radiation safety. The award is given to senior members of the Health Physics Society "in recognition of their significant administrative, educational and/or scientific contributions to the profession of health physics."
Hageman came to the Institute in 1976 as a research engineer in the Nondestructive Testing and Nuclear Services Department, where he managed the radiation control program to ensure compliance with Nuclear Regulatory Commission, Department of Transportation and state of Texas regulations.
In 1987, he transferred to the Center for Nuclear Waste Regulatory Analyses (CNWRA), a federally funded research and development center established by the NRC at SwRI. At the CNWRA, he managed several projects related to the NRC's high-level radioactive waste program and was principal investigator for a project that developed a systematic and comprehensive approach to determine the sufficiency and adequacy of NRC regulations for handling high-level waste.
Since 1996, Hageman has served as SwRI's radiation safety officer and is responsible for the use of a large variety of radionuclides under a Broad Radioactive Material License issued for research and development. He is also responsible for the safe operation of a wide variety of radiation-producing machines used for laboratory analyses and SwRI's High-Level Radiation Effects Facility.
Hageman has been a member of the Health Physics Society since 1977 and has served on various national committees for the society including chairman of the Publications Committee and chairman of the Local Arrangements Committee, and since 1999 has been an associate editor of Operational Health Physics, a supplement to the society's scientific journal, Health Physics. In 2003, he was elected to the society's Board of Directors. He has also served as president of the South Texas Chapter (STC), chairman of the STC Nominating Committee and is a member of the STC Task Force for Homeland Security. Since 1984, Hageman has served as editor-in-chief for the STC newsletter, The Billet.
He holds a bachelor of science degree in physics from The University of Texas at Arlington and a master of science degree in radiological sciences-medical health physics from The University of Texas Health Science Center at San Antonio. In 1999, Hageman became a Certified Health Physicist with the American Board of Health Physics. He is co-inventor on one patent, U.S. 5,861,701, "Charged-Particle Powered Battery."
Contact Hageman at (210) 522-2633 or email@example.com.
Published in the Summer 2004 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Joe Fohn.