Guided wave mode conversion phenomenon in composite materials: numerical and experimental study

Wandowski, Tomasz, Paweł Kudela, Paweł Malinowski, and Wiesław Ostachowicz. "Guided wave mode conversion phenomenon in composite materials: numerical and experimental study." In Health Monitoring of Structural and Biological Systems XIII, vol. 10972, p. 109720N. International Society for Optics and Photonics, 2019.

In this paper results of numerical and experimental analysis of S0/A0 elastic wave mode conversion phenomenon at various discontinuities in glass fibre reinforced polymer (GFRP) panels are presented. Analysis of S0/A0 mode conversion effect at Teflon inserts simulating delamination and impact damage with energies 5 J, 10 J and 15 J is conducted....................

 The aim of its application is to indicate the depth of discontinuity and to prove that delamination was created in the case of impact damage. The auxiliary method is based on terahertz spectroscopy (THz) where the analysis of propagation of electromagnetic waves in the terahertz band is conducted. The THz spectroscopy is a useful technique for damage assessment in the dielectric materials.

for full paper and abstract see https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10972/109720N/Guided-wave-mode-conversion-phenomenon-in-composite-materials--numerical/10.1117/12.2512682.short?SSO=1 

… The THz spectroscopy could be also utilised for non-destructive testing of dielectric
materials like GFRP [26], [27]. Terahertz spectrometer Teraview TPSSpectra 3000+ utilised
during the research generates impulses in the frequency range from 0.1 - 3 THz …