Accession Number:

ADA172130

Title:

Elastic Wave Scattering by Surface-Breaking Planar and Non-Planar Cracks,

Descriptive Note:

Corporate Author:

COLORADO UNIV AT BOULDER DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

• Shah, A. H.
• Chin, Y. F.
• Datta, S. K.

Report Date:

1986-08-01

Pagination or Media Count:

17.0

Abstract:

At present ultrasonic techniques for characterizing defects are being explored vigorously at various research centers around the world. Currently, the ultrasonic approach to defect sizing and characterization is beginning to find great favor for in- or out-of-service use. A recent review of practical ultrasonic nondestructive evaluation is referred. Because of recent advances in experimental ultrasonic technology, increasing demands are being put on quantitative theoretical modeling of scattering of ultrasonic elastic waves by cracks, cavities and other material inhomogeneities in an elastic medium. With a view to obtain detailed information about signals scattered from complex defects various analytical and numerical techniques have emerged. In this article we present a combined finite elements and eigenfunction expansion technique for solving scattering problems involving multiple scattering as well as complex geometries. Numerical results obtained by this method are compared with recent experimental results. In the following we first summarize the theoretical treatment. Then we present the finite elements and eigenfunction expansion technique FEEET. Numerical and experimental results are presented next. Although the results presented here are for homogeneous materials, the method can readily be extended to composite materials.

Descriptors:

• *NONDESTRUCTIVE TESTING
• *CRACKS
• *ULTRASONICS
• *ACOUSTIC SCATTERING
• *ULTRASONIC TESTS
• *DEFECT ANALYSIS
• MODELS
• MATERIALS
• COMPOSITE MATERIALS
• FINITE ELEMENT ANALYSIS
• THEORY
• ELASTIC PROPERTIES
• EIGENVALUES
• DEFECTS(MATERIALS)
• GEOMETRY
• HETEROGENEITY
• ELASTIC SCATTERING
• EXPANSION
• NUMERICAL METHODS AND PROCEDURES
• HOMOGENEITY
• ELASTIC WAVES

Subject Categories:

• Test Facilities, Equipment and Methods
• Acoustics
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE