Divide-and-Conquer Approach Applied to Impedance Analysis of Pipe Eddy Current Test

This paper proposes a unique analytical method for eddy current impedance model of ferromagnetic pipe. Based on the asymptotic behavior of Bessel function in model under bulk quantity occasion, the method exploits the divide-and-conquer approach in the generalized integral interval to simplify model calculation. The calculation results of the model are compared with the results of practical pipe eddy current test, verifying the correctness and feasibility of calculation on the divide-and-conquer approach. The analytical method has the advantages of conciseness and high precision for impedance model applications under cylindrical coordinate systems.