On completion of this subject the student should be able to:
1. Discuss the various kinds of mechanical waves in solids and at interfaces;
2. Explain how ultrasonic waves are generated and how they are used to detect imperfections in solids;
3. Explain the physical basis of eddy current methods of defect detection;
4. Discuss the physical basis of holography and explain how holography is employed in non-destructive testing.
Ultrasonics; Review of elementary wave theory; Bulk waves in solids, longitudinal (compression) waves and transverse (shear) waves; Polarization; Expressions for velocity of compression and shear waves; Surface waves in solids; Free surfaces, Rayleigh waves; Dispersion relations; Liquid/solid and solid/solid interfaces; Stoneley waves; Love waves; Lamb waves; Acoustic impedance of boundaries; Mode conversion; Ultrasonic optics; Diffraction effects; Attenuation; Ultrasonic generators; Piezoelectric effect; Magnetostrictive effect; Electromagnetic-acoustic effect; Thermoelastic effect; Practical applications; Probe output and calibration; Distance-amplitude correction; Probe configurations; Detection and characterization of defects; Electromagnetic methods; The impedance plane diagram; Skin effect; Eddy current methods; Pulsed eddy currents; Probe design and instrumentation; Holography; Coherence and interference of light rays; Summary of hologram types: transmission, reflection and phase holograms; Fresnel diffraction and the zone plate; Optical holography, speckle pattern interferometry; Acoustic holography; Neutron holography.
Halmshaw, R., Non-destructive testing, Edward Arnold, London, UK, 1991.
Continuous assessment 40%
Written examination 60%
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