Vibro-Acoustic Modulation for damage detection

Vibro-Acoustic Modulation is a nonlinear vibration method for the Non-Destructive Evaluation of structural health. It employs a low-frequency, high-amplitude pumping vibration coupled with a high-frequency, low-amplitude probing vibration to create highly nonlinear responses in regions with defects. Those nonlinear responses show up as frequency sidebands in the frequency response plot. The amplitudes of these sidebands generally correlate with the severity of the defect. 

VAM has been applied for the detection of composites damage such as delamination and "kissing" bond - a debonding defect that stays in close contact, making its detection by C-scan difficult.

For more details, please see our publications:

• First work on the experimental setup, including 1D theoretical derivations of sidebands in the appendix

• Subsequent work on the finite element simulation of VAM and more-involved theoretical derivations.

• Subsequent work on the 3D finite element simulation with in-depth analysis on the sub-harmonics.