Rayleigh Wave Nondestructive Evaluation for Defect Detection and Materials Characterization

1999 ◽  
Author(s):  
Philip L. Marston ◽  
Scot F. Morse ◽  
Karen Gipson

Abstract In ultrasonic nondestructive evaluation and sonar imaging, scattering contributions by leaky waves on truncated objects can be important for enhancing the visibility of certain of the borders of the scatterer. A method of approximating the leaky wave contributions is reviewed together with recent experimental and computational tests for evaluating that method in situations where the scattering contributions are large. The tests include meridional ray contributions to the scattering by tilted solid cylinders and cylindrical shells and Rayleigh wave contributions for steel cubes in water.


2003 ◽  
Vol 17 (08n09) ◽  
pp. 1653-1658 ◽  
Author(s):  
S. J. Song ◽  
Young H. Kim ◽  
D. H. Bae ◽  
M. H. Jung ◽  
S. D. Kwon

The corrosion degradation characteristics of the 12Cr alloy steel, which is widely used in fossil power plants as a turbine blade material, are evaluated nondestructively by use of the backward radiation of propagating Rayleigh wave. For this purpose, an automated system for measuring the ultrasonic backward radiation has been developed, and the frequency dependency of the Rayleigh surface wave has been investigated indirectly by observing the angular dependency of the acquired signals. The velocity of Rayleigh wave decreased as the increase of aging time, which implies the increase of the effective degraded layer thickness. And the peak amplitude of the radiation increased as aging time, which relates to the increase of inter-granular corrosion. The result observed in this study demonstrates high potential of the backward radiated ultrasound as a tool for nondestructive evaluation of the corrosion degradation characteristics of aged materials.


MRS Bulletin ◽  
1996 ◽  
Vol 21 (10) ◽  
pp. 18-21 ◽  
Author(s):  
Theodore E. Matikas ◽  
Robert L. Crane

Characterization of materials properties is critical for the understanding of materials behavior and performance under operating conditions. Tailoring materials properties, which are functions of the materials states, is essential for advanced product design. The need to characterize materials for a myriad of applications has spurred the development of many new methods and instruments. Unfortunately many of these characterization tools require destructive sectioning. Also many characterization techniques do not provide key information about material parameters in their operating environments. An ideal characterization tool would provide data about the material properties that are related to micro-and macrostructure without destructive sectioning. Such data can only be obtained using nondestructive-evaluation (NDE) methodologies. Therefore NDE is essential for almost any industrial product. Nondestructive evaluation has become an integral part of materials research because it enables the determination of material parameters (such as micro- and macrostructure, stress, physical properties, and defects) at nearly any point, line, surface, or volume element of interest and at nearly any state during the life of the material. Nondestructive evaluation is based on many different methods that rely on elastic waves, penetrating radiation, light, electric and magnetic fields, chemical sensing, etc. The large number of potential methods makes NDE not a single field but a synergism of many scientific and engineering disciplines. Since it would be impractical here to present all the new NDE methodologies with application to materials research, this issue of MRS Bulletin focuses exclusively on those ultrasonic techniques that are increasingly important in materials characterization.


1988 ◽  
Vol 142 ◽  
Author(s):  
Robert E. Green

AbstractIn recent years classical nondestructive testing techniques for detecting macroscopic defects have been augmented by more sophisticated nondestructive evaluation methods for characterizing the microstructure and associated physical and chemical properties of materials. This paper will briefly describe several such nondestructive evaluation methods developed in the Center for Nondestructive Evaluation (CNDE) at The Johns Hopkins University.


2000 ◽  
Vol 2000 (0) ◽  
pp. 351-352
Author(s):  
Takahiro KUBO ◽  
Taiji HIRASAWA ◽  
Ichiroh KOMURA ◽  
Koichiro KAWASHIMA

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