Simulation of Radio Frequency Inductive Testing (RFIT) for deep sub-surface defects in concrete

Radio Frequency Inductive Testing (RFIT) is a new nondestructive technology that is typically used in damage detection in thin CFRP composites. The method utilizes a pair of inductive coils using low-frequency magnetic field waves to detect subsurface defects. In this paper, we investigate the proof of concept of RFITs in the structural health monitoring of the concrete structures. The study includes electromagnetic simulations of a single coil using the manufacturer specifications which correlates the physical properties of the sensors used in the experiments. The initial results showed that increased frequency results in a decreased magnetic field penetration. Additionally, two coupled coils are simulated in order to increase the detection depth. For a range of driving frequencies, the resulting magnetic field and the received voltage is examined. The results showed that the placement of a discontinuity in concrete such as steel could cause a strong coupling to the magnetic field and additionally alter the received voltage. Theoretically differing sizes and depths of defects should be detectable and distinguishable.