Location

Brunswick, ME

Start Date

1-1-1990 12:00 AM

Description

The most common technique to determine the elastic constants of anisotropic materials from ultrasonic wave speed measurements requires that the material be cut into samples such that particular symmetry directions can be accessed for normal incidence wave speed measurements.[1,2] This is a destructive technique and is not feasible for thin or inhomogeneous materials. A truly nondestructive technique is needed. Recent work along these lines has addressed composite materials using ultrasonic immersion techniques.[3–7] However these methods have been limited to measurements in symmetry planes. Due to this limitation, all of the elastic constants can not be obtained by this technique alone. Two of the limiting factors are: the lack of a general analytic closed form solution for elastic wave propagation in anisotropic materials and that the energy vector does not, in general, lie in the plane formed by the incident wave and the refracted phase velocity. However, general analytic closed form solutions have been recently reported, removing the first of the limitations.[8,9] The second limitation greatly complicates the analysis of the problem.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

9B

Chapter

Chapter 8: Characterization of Materials

Section

Properties

Pages

1565-1572

DOI

10.1007/978-1-4684-5772-8_201

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Ultrasonic Determination of Elastic Constants from Oblique Angles of Incidence in Non-Symmetry Planes

Brunswick, ME

The most common technique to determine the elastic constants of anisotropic materials from ultrasonic wave speed measurements requires that the material be cut into samples such that particular symmetry directions can be accessed for normal incidence wave speed measurements.[1,2] This is a destructive technique and is not feasible for thin or inhomogeneous materials. A truly nondestructive technique is needed. Recent work along these lines has addressed composite materials using ultrasonic immersion techniques.[3–7] However these methods have been limited to measurements in symmetry planes. Due to this limitation, all of the elastic constants can not be obtained by this technique alone. Two of the limiting factors are: the lack of a general analytic closed form solution for elastic wave propagation in anisotropic materials and that the energy vector does not, in general, lie in the plane formed by the incident wave and the refracted phase velocity. However, general analytic closed form solutions have been recently reported, removing the first of the limitations.[8,9] The second limitation greatly complicates the analysis of the problem.