@inproceedings{01J0K552ZXHZTEJR70ABSCPNFJ,
  abstract     = {{Composite structures are increasingly used in high-tech industry because of their good mechanical performance. However, the perennial challenge associated with the utilization of composites pertains to the potential presence of internal defects. It is imperative to conduct inspections for detecting internal damage to ensure a safe structural operation.
A non-destructive inspection approach, based on the guided elastic wavefield, is presented for damage imaging in composite plates. Guided elastic waves are excited using two piezoelectric actuators bonded on the specimen. One actuator is fed with a broadband sine sweep signal, while the other is supplied with a single frequency sine signal. The full-field vibrational response at the surface of the tested part is measured by 3D infrared scanning laser Doppler vibrometry. The construction of specific time-frequency bandpass filters allows to isolate of certain nonlinear wave components, such as the higher harmonics and modulation sidebands. By pixel-wise computing the bandpower of the filtered nonlinear components, a high-quality damage map is obtained.
A series of tests are carried out on several specimens, and it is illustrated that both the second higher harmonic and the first modulation sideband offer distinct imaging of defect nonlinearity, while the latter is unaffected by source nonlinearity. The effect of both the intensity and the bandwidth of the excitation signal on the generated nonlinear components is studied in order to get in-depth information on the nonlinear behavior of defects. Finally, a Gaussian process regression is implemented to cope with a sparse measurement grid, and to obtain a more region-specific and smooth visualization of damage.}},
  author       = {{Liu, Yongcheng and Chronopoulos, Dimitrios and Talemi, Reza and Van Paepegem, Wim and Kersemans, Mathias}},
  booktitle    = {{11th European Workshop on Structural Health Monitoring (EWSHM 2024), Abstracts}},
  keywords     = {{Guide Waves,Non-destructive Testing,Composites,Nonlinearity,Damage Imaging}},
  language     = {{eng}},
  location     = {{Potsdam, Germany}},
  pages        = {{18}},
  title        = {{NWMS-based damage imaging in composites and exploration of nonlinearity evolution}},
  url          = {{https://ewshm2024.com/frontend/index.php?folder_id=112&page_id=}},
  year         = {{2024}},
}