Boundary element solution for the bidimensional scattering of guided waves in laminated plates

Ultrasonic guided waves are being successfully applied to remotely detect defects in large metallic elements. These components are commonly coated for corrosion protection or insulation purposes. Since the coating materials are usually viscoelastic, the inspection range is severely reduced unless an adequate combination of mode and frequency with low attenuation are chosen. The hybrid boundary element-finite element method is applied to study the scattering of low-attenuated modes by hidden corrosion defects. Some trends in the mode conversion factors are highlighted that could be used in long-range NDE applications for defect sizing.