Damage Imaging of Lamb Wave in Isotropic Plate Using Phased Array Delay and Sum Based on Frequency-domain Inverse Scattering Model

ABSTRACT

Among many damage imaging methods based on Lamb wave, phased array Delay and Sum (DAS) has attracted much attention because of its high efficiency. However, inherent dispersion effect leads to the inaccurate acquisition of time-domain features, which affects imaging accuracy. The imaging index based on the amplitude of scattering wave ignores the interaction between Lamb wave and damage, which is difficult to reflect the physical characteristics of damage scattering, and further affects imaging accuracy. We use the physical characteristic parameter-reflectivity of the damage surface as the imaging index and establish an inverse scattering model of damage in frequency domain with dispersion relationship. The simulation and experiment results show that the DAS method combined with the frequency-domain inverse scattering model can realise the high-quality imaging of the damage in the isotropic waveguide structure.

KEYWORDS:

• Lamb wave
• Delay and Sum (DAS)
• dispersion
• imaging accuracy
• inverse scattering model

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by The National Natural Science Foundation of China [11520101001].