Method and device for adjusting array structure of omnidirectional electromagnetic acoustic transducers for imaging defect profile of metal plate

摘要

A method for adjusting array of omnidirectional EMATs includes: uniformly arranging N EMATs in a detection region of a metal plate; calculating positions of scattering points according to amplitudes and travel times of guided wave scattering signals, and forming a first defect profile curve by performing three smooth spline interpolations on coordinate data of positions of scattering points; calculating curvatures of points on the first defect profile curve by solving a first and second derivatives of a function of the first defect profile curve; determining an array adjustment region by comparing the curvature with a preset threshold, adjusting the array and calculating a second defect profile curve; and performing data fusion on the first and second defect profile curves to form a defect profile image of the metal plate.