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KOKTAVÝ, P., ŠIKULA, J., KOKTAVÝ, B.
Original Title
An Electromagnetic Emission SIgnal Generated by A Moving Crack in Solids
English Title
Type
conference paper
Language
Czech
Original Abstract
When a stress is applied to the solids (rocks or tiles) cracks creation can be detected by signals of an acoustic and electromagnetic emission. The experimental study has been performed on rock samples. Two metallic layers have covered the tested devgices to create metal-insulator-metal structure. During the process of the crack generation the electric charges appeared at the face of the cracks. The electric dipole system is a source of voltage induced on metal electrodes. Using Shockley-Ramo thoerem, the differential equation for induced voltage is derived. We found that voltage on measuring capaciotr is directly proportional to the dipole width and its active area. The recorded electric signal is superposition of crack walls :self: vibration given by crack length and vibration due to an ultrasonic wave given by sample dimensions. The electromagnetic signal precedes the acoustic emission response and time delay corresponds to the difference of propagation velocities of sound and electromagnetic radiation in the sample. The simultaneous investigation of acoustic and electromagnetic emission signals enable us to localise the crack position in solids.
Key words in English
nondestructive testin, noise, nonlinearity
Authors
RIV year
2003
Released
1. 1. 2003
Publisher
CNRL
Location
Brno
ISBN
80-238-9094-8
Book
Noise and Non-linearity Testing of Modern Electronic Components
Pages from
134
Pages to
139
Pages count
6
BibTex
@inproceedings{BUT9388, author="Pavel {Koktavý} and Josef {Šikula} and Bohumil {Koktavý}", title="An Electromagnetic Emission SIgnal Generated by A Moving Crack in Solids", booktitle="Noise and Non-linearity Testing of Modern Electronic Components", year="2003", pages="6", publisher="CNRL", address="Brno", isbn="80-238-9094-8" }