Optimal method of bulk wave EMATs used in thick aluminum plate with single flat-bottom hole

Aiming at the problem that the transduction efficiency of electromagnetic acoustic transducers (EMATs) is relatively poor, easily affected by the noise of external environment, which result in small echo signal and low SNR, an optimization method using orthogonal test was introduced.According to the theory of electromagnetics eddy current effect, particle elastodynamics wave equation, and finite element method, a two-dimensional finite element model was established for the bulk wave EMATs in the pulse-echo arrangement, operating on the thick aluminum plate with a single flat-bottom hole.The orthogonal test and extreme difference analysis were applied to consider the parameters of the magnet and coil, which impact on defect echo signal voltage value in different construct, and the optimized model parameters were obtained.Meanwhile, the optimal ratio of magnet width and coil width is gained in this structure.The optimized result validity is verified by the experimental results. It is shown that the experimental peak-peak value of defect reflected waves are in good agreement with simulation.