NDE Research

Listed below are descriptions of several research areas being developed at the Center. Below each description are key articles that provide additional details on the research effort. These papers can be downloaded as PDF files.

Ultrasonic measurement of fluid composition

With today's increased emphasis on product quality and environmental concerns, the operators of industrial processes need better tools to monitor their process and waste streams.

A new ultrasonic technology has been developed which monitors the composition of fluid mixtures from the outside of the pipe or vessel. On-line information is provided about the fluid composition for both product quality assurance and process improvement.

"Ultrasonic Measurement of Fluid Composition," In Review of Progress in QNDE, Vol. 17, Ed. D.O. Thompson and D.E. Chimenti, Plenum (New York), p2177-2183

Treatment systems for ultrasonic hypothermia

This joint research with the University of Colorado Health Sciences Center focuses on measuring the effectiveness of ultrasound induced hypothermia (USHT) for enhanced transport of compounds across the blood brain barrier of live animals. To measure the effectiveness of the hypothemia treatments, it is critical that controlled amounts of ultrasonic energy can be transmitted and restricted to a small treatment zone within the brain. In addition, the temperature rise near this zone must be measured to assure that brain tissue damage does not occur.

A new technique is needed to control of this energy and the monitoring of temperature during treatment. A key outcome of this research is the development of a noninvasive, transkull temperature monitoring technique that may later be extended to human USHT treatment.

Characterization of energetic materials

DRI researchers apply radiographic, ultrasonic and thermographic techniques to verify the integrity of material used in small rockets and munitions. Since 1995, DRI has had a task ordering contract with the Naval Surface Warfare Center to support a number of Navy programs, including the development of inspection systems for rocket motors. DRI has unique capabilities for determining the best inspection technique, and modeling the application of this technique to specific munition systems.

For more information, here is a PDF presentation on inspection techniques for munitions and ordnance: NDE of Energetics.

Topic 2: On-line characterizations of propellants and explosives during manufacture.

Composite propellants are a mixture of a polymeric fuel and a solid oxidizer particle. Nondestructive techniques are under development to monitor many characteristics of these material that are critical for performance and safety including: oxidizer particle size, propellant density and porosity. Recent work at DRI has demonstrated that ultrasonic technology can monitor the status of energetic material during manufacture. Ultrasonics has distinct advantages over other nondestructive methods. It is non-intrusive, quick, portable, low cost, safe, and uses non-ionizing radiation. Analysis of the ultrasonic wave signal can reveal defects and provide information on physical and chemical changes. Although ultrasound has been used for many years to inspect for gross defects, it has not been widely used for materials characterization of energetics used in munitions and ordnance. DRI researchers are currently applying this technology to several DOD applications.

For more information see:

"Ultrasonic monitoring of materials during extrusion manufacture," Proceedings of the JANNAF Nondestructive Evaluation Subcommittee Meeting, Chemical Propulsion Information Agency, Cocoa Beach

Both aging and operational stresses can result in micro-cracking/fissuring of the energetic materials and de-bonding from the case or housing. These defects are among the primary causes of system or device failure. Although it is possible to predict remaining safe life of the energetic materials based on models of the chemical degradation, current methods do not provide adequate confidence far enough into the future to satisfy the needs of planners. Better material property measurement tools are needed to provide the aging data for confirmation of the models. Ideally, these material property measurements would be non-intrusive to the munition. Ultrasound is a low-energy, non-intrusive way to obtain critical chemical composition information on a wide variety of munitions. Ultrasound is perhaps the only technology that can measure physical and chemical changes in a material enclosed in a case, without opening the case. The only requirement is that the energetic materials are in direct contact with the case (e.g. case -bonded). This is true for a large number of Navy munitions and ordnance, such as the Sparrow and Standard Missiles. DRI researchers are working to develop new techniques that monitor the remaining safe life of energetic materials.

"Ultrasonic characterization of propellant aging," Proceedings of the JANNAF Nondestructive Evaluation Subcommittee Meeting, Chemical Propulsion Information Agency, Salt Lake City, Utah, November 1999

Meat tenderness measurement using noninvasive ultrasound

The beef industry needs an objective measure of tenderness that can be used to place value on a carcass, and tell cattlemen when they're breeding better stock. In the long term, implementing such a measure will improve the quality of all beef being sold, as well as the consumer's satisfaction with beef as a meat product.

Our current research goal is to develop ultrasonic technology to predict cooked meat tenderness based on backscattered signals from raw rib-eye samples. A noninvasive ultrasonic transducer is passed over the ribeye area of a carcass and measures ultrasound waves reflected from the meat fibers. The data is fed into a computer, and algorithms predict tenderness based on key features of the ultrasonic signals.