Wave propagation and scattering

COURSE CONTENT

• Introduction, link with non-destructive testing, ultrasonic method, Acoustic Emission (AE) method, correlation with wave propagation and scattering.
• Definitions, homogeneous and non-homogeneous waves, propagation, reflection, refraction, scattering. Damping-Attenuation, Wave Conversion.
• Wave density in space and time (Wavelength, wavenumber), phase velocity.
• Wave Equation in 3 dimensions, plane waves, equipotential surfaces, characteristic equation, dispersion, attenuation.
• Elastic waves, isotropic homogeneous material and what types of waves can propagate, determination of phase velocities and polarization vectors.
• Anisotropic materials, determination of propagation velocities and polarization vectors of elastic waves on anisotropic media, slowness curves.
• Oblique incidence, Snell’s law, critical incidence angles, reflection and refraction factors between two semi-infinite media.
• Definition of Group Velocity, differences from phase velocity.
• Plate waves, Natural significance, types, solutions, dispersion curves, applications.

LEARNING OUTCOMES 

The goal of the module is to acquaint the student with the fundamental aspects of wave propagation and scattering in isotropic and anisotropic materials. To acquaint with the basic mathematics that describe the problem of wave propagation in continuum elastic media. Study the type of waves that propagate in infinite, semi-infinite and fully bounded (e.g. thin walled) media. Examples and applications. More specifically:

• Introduction, link with non-destructive testing, ultrasonic method, Acoustic Emission (AE) method, correlation with wave propagation and scattering.
• Definitions, homogeneous and non-homogeneous waves, propagation, reflection, refraction, scattering. Damping-Attenuation, Wave Conversion.
• Wave density in space and time (Wavelength, wavenumber), phase velocity.
• Wave Equation in 3 dimensions, plane wave, equipotential surfaces, characteristic equation, dispersion, attenuation.
• Elastic waves, isotropic homogeneous material and what types of waves can propagate, determination of phase velocities and polarization vectors.
• Anisotropic materials, determination of propagation velocities and polarization vectors of elastic waves on anisotropic media, slowness curves.
• Oblique incidence, Snell’s law, critical incidence angles, reflection and refraction factors between two semi-infinite media.
• Definition of Group Velocity, differences from phase velocity.
• Plate waves, Natural significance, types, solutions, dispersion curves, applications.