Location

La Jolla, CA

Start Date

1-1-1989 12:00 AM

Description

Eddy-current inspection of advanced composite materials appears to overcome some of the difficulties typical of ultrasonic inspection. For example, carbon-carbon material can be inspected using eddy-currents without making the sample wet or using any acoustic coupling substances. Eddy-current inspection is very good for detecting fibers and fiber content because the fibers usually conduct electricity very well. Eddy-current measurements can therefore detect broken fibers in many cases where ultrasonic inspection fails to find the damage (broken fibers are not always good at scattering the ultrasonics). One of the common arguments against using eddy-currents to inspect composite materials is that they are unable to detect delaminations. This paper presents experimental evidence that suggests that delaminations can be detected with eddy-current inspection. Sabbagh [4] offer theoretical reasoning for the delamination behavior. This paper also presents some experimental data that indicates fiber structure, impact damage, and drilled holes in advanced composite material, including carbon-carbon and graphite-epoxy.

Volume

8B

Chapter

Chapter 8: Composites

Section

Composites—Properties

Pages

1519-1526

DOI

10.1007/978-1-4613-0817-1_191

Language

en

File Format

application/pdf

Share

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Jan 1st, 12:00 AM

Detecting Micro-Structure and Flaws in Composites Using Eddy-Current Instrumentation

La Jolla, CA

Eddy-current inspection of advanced composite materials appears to overcome some of the difficulties typical of ultrasonic inspection. For example, carbon-carbon material can be inspected using eddy-currents without making the sample wet or using any acoustic coupling substances. Eddy-current inspection is very good for detecting fibers and fiber content because the fibers usually conduct electricity very well. Eddy-current measurements can therefore detect broken fibers in many cases where ultrasonic inspection fails to find the damage (broken fibers are not always good at scattering the ultrasonics). One of the common arguments against using eddy-currents to inspect composite materials is that they are unable to detect delaminations. This paper presents experimental evidence that suggests that delaminations can be detected with eddy-current inspection. Sabbagh [4] offer theoretical reasoning for the delamination behavior. This paper also presents some experimental data that indicates fiber structure, impact damage, and drilled holes in advanced composite material, including carbon-carbon and graphite-epoxy.