Affiliations: [a] State Key Laboratory of Mechanics and Control for
Mechanical Structures, Nanjing University of Aeronautics & Astronautics,
Nanjing, Jiangsu, China | [b] Institute of Fluid Science, Tohoku University, Sendai,
Japan | [c] Department of Mechanical Engineering, Chiba
University, Chiba, Japan
Correspondence:
[*]
Corresponding author: Jinhao Qiu, State Key Laboratory of
Mechanics and Control for Mechanical Structures, Nanjing University of
Aeronautics & Astronautics, #29 Yudao Street, Nanjing 210016, Jiangsu,
China. Tel./Fax: +86 25 84891123; E-mail: qiu@nuaa.edu.cn
Abstract: This paper deals with eddy current testing simulation for
carbon-fibre reinforced polymer composites (CFRPs) using an edge –
element FEM code. The FEM code is based on the A formulation and it uses the
coupled analysis with external fields. The coil impedance variations due to the
fibre orientation and cracks in CFRP plates with unidirectional plies are
computed. The conductivity of CFRP is characterized as low value and high
anisotropy, which cause the distinct difference between CFRP and isotropic
metal ECT signals. The correlation of the fibre orientation with coil impedance
variations is obtained, but the exact fibre arrangement in a composite plate
can't be ascertained because of signal symmetry. Another method for determining
the fibre orientation via the edge effect is presented in this study. According
to the numerical results, the shape of cracks in a CFRP plate is not easily
evaluated from the detection signal curves unless the fibre orientation is
perpendicular to the crack path.
Keywords: Carbon-fibre reinforced polymer, Eddy Current Testing, numerical simulation, Finite Element Method, fibre orientation
