Deformation of short fibre reinforced polymers: Correlation between results obtained by acoustic emission and X-ray computed tomography

Abstract

Acoustic emission (AE) is a suitable method to detect micro deformation processes occuring during loading of short fibre reinforced polymers. In principle, characteristic effects like fibre fracture, debonding and matrix deformation can be detected and distinguished. Nevertheless there is some uncertainty in interpreting the results and giving direct correlation to the different sources of acoustic signals. Some approaches were done by insitu scanning electron microscopy coupled with acoustic emission [1]. But it should be kept in mind that in that case only a relative small part on the surface could be observed. The most part of the acoustic signals develop in der whole damaged region around the crack-tip. X-ray computed tomography with µm resolution gives the possibility to characterize the debonding (void generation) and fibre fracture. By quantitative analysis of the amount of events detected by tomography a good correlation with the number, size and frequency characteristics of the AE signals can be shown.