Error Compensation of Planar Location of Acoustic Emission Sources in Composite Materials Using the Jacobian Matrix

Abstract

In this paper, a methodology for improving the accuracy of planar location of acoustic emission (AE) source in composite materials has been presented. The effect of acoustic property anisotropy on AE pulse propagation velocity and on the planar location error has experimentally been established using the standard algorithm. The maximal error in planar location for an isotropic aluminum plate has not exceed 10.9 mm, whereas for a composite material plate, it has reached 104.9 mm. To reduce the error in calculating the coordinates of acoustic emission sources caused by changes in velocity depending on the direction of propagation of acoustic signals, an algorithm for compensatory scaling of planar location using the Jacobian matrix has been developed. The algorithm has been implemented during preliminary tests simulating AE pulses at the nodes of a coordinate grid applied to the surface of a composite plate. The coefficients of the Jacobian matrix and the components of the residual vector have been calculated based on the results of constructing a discrete field of indication displacements. As a result of applying the developed method, the average error of planar location compared to the standard algorithm and the Δt-mapping method decreased by approximately two and 1.2 times, respectively.