Session: Structural Health Monitoring I & II, Material Characterization by Ultrasonic wave

Paper Number: 164217

164217 - Passive Identification of Structural Complex Wave-Number Space via Ambient Noise: Application to Airfoil Icing Detection 

Abstract: 

A passive approach to identify the complex wavenumber via ambient noise is proposed in this paper. Ambient noise such as flow-induced vibration and machinery vibration have been tested (for example, the vibration induced by an air-jet, household hairdryer and an axial flow fan). The structural impulse response between two measurement points can be retrieved via cross-correlation technique. With the direct arrival of impulses response between two sensors, the wave propagating along the measurements line can be retained, by eliminating the coda wave of impulses response between two sensors. A measurement strategy with unequal spacings is employed, a reliable identification of complex wavenumber can be achieved with only 8 sensors in a line, using inhomogeneous wave correlation technique. The mechanical property of material can be revealed from the complex wavenumber, with the dispersion curve reconstructed by the real part of wavenumber and the damping behavior quantified by the imaginary part of wavenumber. The proposed method can be applied in passive ice detection, where the ice thickness can be estimate by minimizing the error between the reconstructed dispersion curve and its theoretical model solved from the Rayleigh–Lamb equations for the two-layer (ice-plate) structure. The result shows the ice detection method based on wavenumber performs well in the thin ice detection.The imaginary part of wavenumber provides the information about wave attenuation in ice material, leading to accurate and reliable assessment for the icing condition.

Presenting Author: Qihang Qin Beihang University

Presenting Author Biography: My research focuses on structural health monitoring using guided waves, particularly passive methods. Instead of relying on actively generated guided waves from excitation equipment, my work utilizes ambient noise. My current research explores passive ice detection through flow-induced vibrations, aiming to achieve real-time structural health monitoring for in-flight aircraft under random noise conditions.

Authors:

Qihang Qin Beihang University
Xun Wang Beihang University
Jingjing He Beihang University