Structural health condition monitoring of carbon-fibre based composite materials using acoustic emission techniques

Ning, Weili (2015). Structural health condition monitoring of carbon-fibre based composite materials using acoustic emission techniques. University of Birmingham. M.Sc.

Preview

Ning15MScbyRes.pdf
PDF - Accepted Version
Download (6MB)

Abstract

The general aim of this study is to evaluate the efficiency of the AE technique in monitoring the structural health of CFRP. To reliably establish the link between the AE responses with the evolution of structural damage tests were carried out initially on carbon fibre bundles alone before progressing with tests on plain carbon weave fabric composite specimens fabricated in the laboratory. In certain composite specimens artificial defects such as through-hole defect, deep scratch and notches were intentionally induced to study the effect of these defects on the mechanical properties and AE responses arising during testing. Tensile tests were carried out on carbon fibre bundle and composite specimens. Composite specimens were also tested in three-point bending. AE sensors were used to monitor the structural health condition of all specimens. Due to the complexity of the AE signals recorded from composite specimens, the AE results from the bundle specimens were initially evaluated, compared and then linked to the AE responses resulting from the composite specimen tests. The AE responses collected from tests of defect-free composite specimens were compared to those containing various types of artificially induced defects. From the results acquired it was established that the AE technique can monitor effectively the evolution of damage as load increases. Key parameter indicators based on the energy, counts and duration of the AE signals were determined to be more important than the amplitude of the hits recorded. From the results at hand it can be concluded that the AE technique can be a valuable tool in the evaluation of in-service critical structural CFRP components operating under cycling loading conditions.

Type of Work:

Thesis (Masters by Research > M.Sc.)

Award Type:

Masters by Research > M.Sc.

Supervisor(s):