Ultrasonic attenuation tomography in disks under load

Experiments were performed using tomographic imaging to study the changes in ultrasonic attenuation within a solid disk under load. A Brazilian disk test was performed on solid disks, and ultrasonic waves passed through the sample at various stages of loading. From these data, tomographic images were reconstructed using time of flight, amplitude, and risetime of signals to give variations in acoustic velocity and attenuation as a function of load. These data have been correlated within acoustic emissions emitted during loading. Analysis of these data leads to conclusions concerning the failure modes of the disks