TY - JOUR A1 - Reimund, Verena A1 - Pelkner, Matthias A1 - Kreutzbruck, Marc A1 - Haueisen, J. T1 - Sensitivity analysis of the non-destructive evaluation of micro-cracks using GMR sensors JF - NDT & E international N2 - Micro-cracks in a magnetized ferromagnetic material cause stray fields that can be observed using giant magnetoresistive (GMR) sensors. This work investigates the applicability of GMR sensors to the non-destructive evaluation of micro-cracks via the observation of stray fields. For this purpose, our measurement setup is assessed using a fast new sensitivity analysis based on adjoint states, employing the finite-element method. A model for the GMR sensor is developed and verified. We are able to resolve micro-cracks with an opening of 3 µm and a depth of 30 µm. GMR positioning inaccuracies are analyzed. KW - Adjoint sensitivity analysis KW - Inverse problem KW - Magnetic stray field KW - Magneto-statics PY - 2014 DO - https://doi.org/10.1016/j.ndteint.2014.02.003 SN - 0963-8695 VL - 64 SP - 21 EP - 29 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-32236 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -