Title :
Reconstruction of crack shapes from the MFLT signals by using a rapid forward solver and an optimization approach
Author :
Chen, Zhenmao ; Preda, Gabriel ; Mihalache, Ovidiu ; Miya, Kenzo
Author_Institution :
Int. Inst. of Universality, Tokyo, Japan
fDate :
3/1/2002 12:00:00 AM
Abstract :
In this paper, the reconstruction of crack shapes from magnetic flux leakage testing (MFLT) signals is realized by introducing a rapid forward simulator and applying a deterministic optimization approach. The MFLT signals due to cracks of different shape are calculated with an FEM-BEM code employing the A method and polarization algorithm, which is accelerated by the new rapid forward scheme. For reconstructing the crack shape, the conjugate gradient method is applied with the gradients predicted by using the difference technique. Both inner and outer cracks are successfully reconstructed from simulated MFLT signals that verified both the efficiency of the fast-forward scheme and the feasibility of the deterministic inverse approach
Keywords :
boundary-elements methods; conjugate gradient methods; crack detection; eddy current losses; eddy current testing; electromagnetic wave polarisation; finite element analysis; inverse problems; magnetic leakage; signal reconstruction; A method; FEM-BEM code; MFLT signals; conjugate gradient method; crack shape reconstruction; crack shapes; deterministic inverse approach; deterministic optimization; difference technique; fast-forward scheme; inner crack reconstruction; inverse problems; magnetic flux leakage testing signals; nondestructive testing; optimization; outer crack reconstruction; polarization algorithm; rapid forward scheme; rapid forward simulator; rapid forward solver; Character generation; Computational modeling; Magnetic flux leakage; Magnetic materials; Magnetization; Maxwell equations; Neural networks; Nonlinear equations; Polarization; Shape measurement;
Journal_Title :
Magnetics, IEEE Transactions on
