Study on damage identification of aero-engine composite vane based on experimental modal parameters

The paper took both undamaged and damaged composite plane plates as examples to effectuate the modal experiments by laser vibrometer measurement systems. The plate vibration modal parameters were identified. One coefficient was further constructed to locate the damage position. The experimental results show that the presence of the damage reduces the plate vibration amplitude due to its material deformation. Several orders of frequencies of the plate may not be identified only by the amplitude-frequency curves. For the plate, its first three orders natural frequencies are 67 Hz, 85 Hz and 105 Hz, respectively. The fourth and fifth orders ones correspond to 140 Hz and 225 Hz. The plate's natural frequencies decrease and its damping ratio increases in the presence of the damage on the plate. The plate damage does not change evidently its vibration shape features, but reduces its vibration amplitude. The constructed damage coefficient may identify the damage location in most cases.