Publication detail

A Model for an Electromagnetic signal Generated by Crack Creation in Solids

KOKTAVÝ, P., KOKTAVÝ, B.

Original Title

A Model for an Electromagnetic signal Generated by Crack Creation in Solids

Type

conference paper

Language

English

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 devices to create metal-insulator-metal structure. During the process of the crack generation the electric charges appeared at the faces of the cracks. The electric dipole system is a source of voltage induced on metal electrodes. Using Shockley-Ramo theorem, the differential equation for induced voltage is derived. We found that voltage on measuring capacitor 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.

Keywords

Crack, Electric charge, Electromagnetic emission, Acoustic emission

Authors

KOKTAVÝ, P., KOKTAVÝ, B.

RIV year

2003

Released

1. 1. 2003

Publisher

Brno University of Technology

Location

Brno

ISBN

80-7204-318-8

Book

Proceedings of the Workshop NDT CMC 2003 Non-Destructive Testing of Civil Materials and Constructions

Pages from

47

Pages to

52

Pages count

6

BibTex

@inproceedings{BUT9236,
  author="Pavel {Koktavý} and Bohumil {Koktavý}",
  title="A Model for an Electromagnetic signal Generated by Crack Creation in Solids",
  booktitle="Proceedings of the Workshop NDT CMC 2003 Non-Destructive Testing of Civil Materials and Constructions",
  year="2003",
  pages="6",
  publisher="Brno University of Technology",
  address="Brno",
  isbn="80-7204-318-8"
}