Séminaire: Defect reconstruction in waveguides using resonant frequencies

This presentation introduces a multi-frequency approach for reconstructing width defects in elastic waveguides. Unlike conventional inverse methods, our technique uses resonant frequencies known for their ill-conditioned propagation equations. By investigating the forward problem at these resonant frequencies, we employ a WKB approximation to characterize the wavefield for each modal component. Then, we apply this approximation to address the inverse problem, enabling stable reconstruction of width defects from partial wavefield measurements. We also provide numerical validations and comparative analyses against established methods, alongside experimental validations conducted at Institut Langevin on ZGV resonant frequencies, offering comprehensive insights into the efficacy and reliability of our approach.