Non-Destructive Testing of Carbon Fiber-Reinforced Plastics (CFRPs) Using a Resonant Eddy Current Sensor

Abstract

Eddy current testing (ECT) is commonly used for the detection of defects inside metallic materials. In order to achieve the effective testing of CFRP materials, increasing the operating frequency or improving the coil structure is a common method used by researchers. Higher or wider operating frequencies make the design of the ADC’s conditioning circuit complex and difficult to miniaturize. In this paper, an LC resonator based on inductance-to-digital converters (LDCs) is designed to easily detect the resonant frequency response to the state of the material under test. The reasonableness of the coil design is proven by simulation. The high signal-to-noise ratio (SNR) and detection sensitivity of the LC resonator are demonstrated through comparison experiments involving multiple probes. The anti-interference capability of the LC resonator in CFRP defect detection is demonstrated through various interference experiments.

Assemblies of Coaxial Pick-Up Coils as Generic Inductive Sensors of Magnetic Flux: Mathematical Modeling of Zero, First and Second Derivative Configurations

“…This is why they have been used in a wide range of experimental studies on the properties of magnetic and superconducting materials, either in the form of a single PUC or two PUCs, with dimensions adjusted to the size of each sample [ 30 , 31 , 32 , 33 , 34 , 35 ]. Also, 3D magnetic field sensors based on planar PUCs that can be fabricated relatively easily have been studied by simulations and numerical analyses [ 36 ]; single PUC magnetic field sensors, without and with a core for plasma-based and power-cable applications have been reported so far [ 37 , 38 ], and single PUCs have been incorporated in LC resonators for the nondestructive evaluation of materials [ 39 ].…”