Combined Shear-Compression Ultrasound Reflection Tomography
A new imaging technique has been developed for carrying out real-time ultrasound reflection tomography of cylindrical objects. A circular synthetic aperture is realised by object rotation. Two scans are performed, one isonifying the object with compression waves and the other with shear waves. Each scan is processed separately, using convolution backprojection, and the two resultant tomographic images are then superimposed to form the final image. Images of real defects (voids and cracks) in rods and pipes are presented. It is illustrated that certain classes of defects can only be imaged correctly if the compression and shear images are superimposed to complement each other.
KeywordsShear Wave Compression Wave Shear Velocity Parallel Beam Pulse Transit Time
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