Title :
Lamb wave tomography
Author :
Jansen, D.P. ; Hutchins, D.A.
Author_Institution :
Dept. of Phys., Queen´´s Univ., Kingston, Ont., Canada
Abstract :
Tomographic imaging of the condition of tin materials has been performed using Lamb waves. Lamb waves were generated in thin sheets of aluminum submerged in water using an immersion transducer set at the critical angle. An identical transducer at a fixed separation detected energy radiated back into the water by the propagating Lamb wave. Waveforms from the receiving transducer were captured and stored for a set scan pattern with an automated data collection system under the control of a microcomputer. Both the amplitude variation and propagation delay were used to obtain tomographic images of attenuation and velocity, based on a filtered back-projection technique. Representative reconstructions of both slowness and attenuation variations are shown, illustrating the technique´s success in imaging defects in thin materials
Keywords :
aluminium; computerised tomography; flaw detection; microcomputer applications; surface acoustic waves; ultrasonic materials testing; Al; Lamb wave tomography; amplitude variation; attenuation; automated data collection system; critical angle; defects; filtered back-projection technique; immersion transducer; microcomputer; propagating Lamb wave; propagation delay; receiving transducer; set scan pattern; thin sheets; tin materials; tomographic images; velocity; Aluminum; Attenuation; Automatic control; Control systems; Microcomputers; Propagation delay; Sheet materials; Tin; Tomography; Transducers;
Conference_Titel :
Ultrasonics Symposium, 1990. Proceedings., IEEE 1990
Conference_Location :
Honolulu, HI
DOI :
10.1109/ULTSYM.1990.171515