Presenter Information

N. K. Batra, United States Navy

Location

La Jolla, CA

Start Date

1-1-1989 12:00 AM

Description

The attenuation of propagating ultrasound through heterogeneous materials such as fiber reinforced epoxy composites containing chopped fibers with random orientation is predominantly due to scattering from the fibers as well as from discontinuities such as pores and is consequently frequency dependent. In this paper, we determine the frequency dependent attenuation from the downshifted spectra of the transmitted broadband wavepacket. Such a technique, first used for medical ultrasound, can be very useful for characterization of acoustically very lossy composites, because spectral shifts for such materials can be particularly significant. Experimental results and analytical models are presented for the non-destructive characterization of such composites by this method.

Volume

8B

Chapter

Chapter 8: Composites

Section

Composites—Properties

Pages

1527-1533

DOI

10.1007/978-1-4613-0817-1_192

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Ultrasonic Spectral Analysis for Characterization of Composites

La Jolla, CA

The attenuation of propagating ultrasound through heterogeneous materials such as fiber reinforced epoxy composites containing chopped fibers with random orientation is predominantly due to scattering from the fibers as well as from discontinuities such as pores and is consequently frequency dependent. In this paper, we determine the frequency dependent attenuation from the downshifted spectra of the transmitted broadband wavepacket. Such a technique, first used for medical ultrasound, can be very useful for characterization of acoustically very lossy composites, because spectral shifts for such materials can be particularly significant. Experimental results and analytical models are presented for the non-destructive characterization of such composites by this method.