Measurement and Study of Electromagnetic Emission Generated by Tensile Fracture of Polymers and Carbon Fibres

Abstract

Electromagnetic emission (EME) signals generated by tensile fracture of four different types of polymers and three different carbon fibre types are presented and discussed. A suitable set-up for the detection of the electric field component of EME generated by fracture of solids is proposed. Basic theoretical considerations are made about the coupling between these field components and the capacitive sensors used to directly measure the short ranged and low frequency (kHz-MHz) electric fields emitted by the generation of free surface charges and their spatial movement as dictated by the vibrational motion of the crack walls. Special focus is put on solids with low conductivity, where the influences of the material on the emitted fields is small and the detected electric signals almost solely depend on the source dynamics and the sensor characteristics. Analysis of the influence of the acquisition circuit is presented. The discussion of the electric signals emitted by tensile fracture of carbon fibres and polymer specimens comprises the influences of the material properties on the signals as well as correlations between the signals and the crack dynamics, including the crack propagation velocities.

Investigating the Mechanical Properties of Polymer Samples from Different Additive Manufacturing Processes Using Ultrasonic Phase Spectroscopy

“…Other nondestructive testing methods, such as acoustic emission, 14 infrared thermography, 15 or electromagnetic emission, 16 are mainly used for the detection of cracks and other defects in critical parts such as airplane components or wind turbines. Therefore, they are essential and widely used for the health monitoring of these parts, and the methods are used regularly to spot defects at an early stage.…”

A review on deformation-induced electromagnetic radiation detection: history and current status of the technique

“…Among these, deformation-induced electromagnetic emission (EME) detection has evolved as an intriguing research area from the last one century [13]. Here the term electromagnetic emission (EME) is used to represent different effects such as electromagnetic radiation (EMR) emitted during and after local mechanical processes, such as crack propagation, fracture, plastic deformation or friction as well as the emission of charged particles such as electrons, ions, neutral species and photons (which is commonly known as fractoemissions) [14]. EME and EMR are used interchangeably in the present work with respect to the best suitability of use while both reflecting the same phenomenon.…”