2019 Volume 45 Issue 3 Pages 105-113
Measurement of the elastic moduli of carbon fiber reinforced plastics (CFRP) can be difficult owing to the anisotropic and viscoelastic characteristics of CFRP. In this study, a technique based on resonant ultrasound spectroscopy is proposed that can identify the viscoelastic moduli of CFRP by measuring the resonant frequencies. The resonant frequencies of a CFRP specimen were measured by employing an experimental device comprising a pair of piezoelectric transducers and the spectrum analyzer software. The viscoelastic moduli were thereby identified by applying genetic algorithms. Considering the viscoelastic properties, it is possible to conduct highly accurate analysis as compared to the case in which the viscoelastic properties are not considered. Furthermore, by measuring the resonance modes that are significantly affected by the three independent viscoelastic moduli (EL, ET, GLT), each modulus can be identified with constant precision.
