Detecting Damage in Carbon Fibre Composites using Numerical Analysis and Vibration Measurements

Abstract

In this work, carbon fibre reinforced polymer (CFRP) plates have been tested under free impact vibration tests in pristine and damaged configurations. The plates were suspended as cantilevers and vibrated using an impact hammer. Two accelerometers and one microphone were used to obtain the vibration response data signals from the pristine and damaged plates, and the frequency response function (FRF) was plotted. The current technique focused on the detected signal from more than one vibration sensor to ensure the measurement's accuracy. Comparisons between the experimental vibration test and the simulated analysis using finite element analysis (FEA) showed that the results agreed. The damage orientation significantly affected the composites’ dynamic properties. The FRF measures of the damaged CFRP composites showed the lowest eigenvalues in the resonant frequencies. The 0/90 layup laminate composite exhibited greater fluctuations in resonant frequencies across the various mode shapes, which reached a 2.85% difference compared to the quasi-isotropic laminate composites.

Keywords:
Carbon Fibre Reinforced Polymer (CFRP); Damage; Frequency Response Function (FRF); CFRP; Damping; Mode Shape

Graphical Abstract