Defect Detection in Carbon Fiber-Reinforced Plate by Imaging of Mechanical Nonlinearity-Induced Sideband Vibrations
Tommaso Seresini,
Sevilia Sunetchiieva,
Helge Pfeiffer,
Martine Wevers,
Christ Glorieux
Affiliations
Tommaso Seresini
Laboratory of Soft Matter and Biophysics, Department of Physics and Astronomy, Katholieke Universiteit Leuven, Celestijnenlaan 200D, P.O. Box 2416, 3001 Heverlee, Belgium
Sevilia Sunetchiieva
Structural Composites and Alloys, Integrity and Nondestructive Testing (SCALINT) Group, Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, P.O. Box 2450, 3001 Leuven, Belgium
Helge Pfeiffer
Structural Composites and Alloys, Integrity and Nondestructive Testing (SCALINT) Group, Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, P.O. Box 2450, 3001 Leuven, Belgium
Martine Wevers
Structural Composites and Alloys, Integrity and Nondestructive Testing (SCALINT) Group, Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, P.O. Box 2450, 3001 Leuven, Belgium
Christ Glorieux
Laboratory of Soft Matter and Biophysics, Department of Physics and Astronomy, Katholieke Universiteit Leuven, Celestijnenlaan 200D, P.O. Box 2416, 3001 Heverlee, Belgium
Laser Doppler scanning vibrometry is used for imaging spectral vibration components in a carbon fiber-reinforced composite plate that contains a sub-surface delamination defect caused by hammer impact. The images reveal sideband generation at the location of the defect, reflecting mechanical nonlinearity-induced mixing between a high amplitude, low-frequency vibration that modulates the stress–strain behavior near the defect and a low amplitude, high-frequency probe vibration. In this work, a multifrequency probe is used to tackle the problem that the mixing coefficients are, in practice, frequency dependent. Based on the measured sideband amplitudes, a study is presented on the expected feasibility of detecting defects by a full field imaging scheme based on a photorefractive interferometer that is configured as a vibrometer acting as a bandpass filter around a sideband frequency of interest.
