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in creator/contributor: "Deason, Vance Albert"

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Imaging Laser Ultrasonics Measurement of the Elastodynamic Properties of Paper

Many sheet and plate material industries (e.g. paper) desire knowledge of the anisotropic stiffness properties of their material to optimize the manufacturing process. A determination of the anisotropic elastic matrix would be very beneficial for determination of parameters, such as as microstructural texture, fiber or grain orientation and stiffness. The propagation of ultrasonic waves in plates is a method for determining the anisotropic elastic properties in a nondestructive manner. Laser ul… more

Date: October 1, 2001

Creator: Telschow, Kenneth Louis & Deason, Vance Albert

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of ultrasonic traveling wave surface displacement and phase in all planar directions simultaneously without scanning. The imaging method performs optical lock-in operation. A single antisymmetric Lamb wave mode image produces direct quantitative determination of the phase velocity in all planar directions showing plate stiffness anisotropy. Excellent agreemen… more

Date: May 1, 1999

Creator: Telschow, Kenneth Louis; Deason, Vance Albert & Datta, S.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultrasonic Imaging of Subsurface Objects Using Photorefractive Dynamic Holography

The INEEL has developed a photorefractive ultrasonic imaging technology that records both phase and amplitude of ultrasonic waves on the surface of solids. Phase locked dynamic holography provides full field images of these waves scattered from subsurface defects in solids, and these data are compared with theoretical predictions. Laser light reflected by a vibrating surface is imaged into a photorefractive material where it is mixed in a heterodyne technique with a reference wave. This demodul… more

Date: July 1, 2001

Creator: Deason, Vance Albert; Telschow, Kenneth Louis & Watson, Scott Marshall

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Imaging of Acoustic Waves in Sand

There is considerable interest in detecting objects such as landmines shallowly buried in loose earth or sand. Various techniques involving microwave, acoustic, thermal and magnetic sensors have been used to detect such objects. Acoustic and microwave sensors have shown promise, especially if used together. In most cases, the sensor package is scanned over an area to eventually build up an image or map of anomalies. We are proposing an alternate, acoustic method that directly provides an image … more

Date: August 1, 2003

Creator: Deason, Vance Albert; Telschow, Kenneth Louis & Watson, Scott Marshall

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultrasonic Imaging and Theoretical Prediction of Orthotropic Plate Stiffness in all Planar Directions

Exact and approximate theoretical analysis of the wavelengths of plate wave mode propagation in all planar directions for the dispersive antisymmetric Lamb wave mode are compared with measurements from a laser ultrasonic imaging approach that records the out of plane ultrasonic motion over a large area in a single frame without scanning. Good agreement is demonstrated, based on independent determination of the elastic constants, for two different types of paper.

Date: July 1, 2000

Creator: Telschow, Kenneth Louis; Deason, Vance Albert; Mukdadi, O. & Datta, S. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Material Property Measurement of Metallic Parts using the INEEL Laser Ultrasonic Camera

Ultrasonic waves form a useful nondestructive evaluation (NDE) probe for determining physical, microstructural, and mechanical properties of materials and parts. Noncontacting laser ultrasonic methods are desired for remote measurements and on-line manufacture process monitoring. Researchers at the Idaho National Engineering & Environmental Laboratory (INEEL) have developed a versatile new method for detection of ultrasonic motion at surfaces. This method directly images, without the need for s… more

Date: August 1, 1999

Creator: Telschow, Kenneth Louis; Deason, Vance Albert; Schley, Robert Scott & Watson, Scott Marshall

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Imaging of Lamb Waves in Plates for Quantitative Determination of Anisotropy using Photorefractive Dynamic Holography

Anisotropic properties of sheet materials can be determined by measuring the propagation of Lamb waves in different directions. Electromagnetic acoustic transduction and laser ultrasonic methods provide noncontacting approaches that are often desired for application to industrial and processing environments. This paper describes a laser imaging approach utilizing the adaptive property of photorefractive materials to produce a real-time measurement of the antisymmetric Lamb wave mode in all dire… more

Date: June 1, 1998

Creator: Telschow, Kenneth Louis; Deason, Vance Albert; Schley, Robert Scott & Watson, Scott Marshall

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Direct Imaging of Anisotropic Material Properties using Photorefractive Laser Ultrasound

Anisotropic properties of materials can be determined by measuring the propagation of elastic waves in different directions. A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of the antisymmetric Lamb or flexural traveling wave mode displacement and phase. Continuous excitation is employed and the data is recorded and displayed in all directions simultaneously at video camera frame rates. Fourier transform o… more

Date: July 1, 1999

Creator: Telschow, Kenneth Louis; Deason, Vance Albert; Schley, Robert Scott & Watson, Scott Marshall

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Full-Field Imaging of Acoustic Motion at Nanosecond Time and Micron Length Scales

A full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning. Images are recorded at normal video frame rates by employing dynamic holography using photorefractive interferometric detection. By extending the approach to ultra high frequencies, an acoustic microscope has been developed capable of operation on the nanosecond time and micron length scales. Both acoustic amplitude and phase are recorded allowing full calibration an… more

Date: October 1, 2002

Creator: Telschow, Kenneth Louis; Deason, Vance Albert; Cottle, David Lynn & Larson, John D., III

Item Type: Article

Partner: UNT Libraries Government Documents Department