Further Studies on the Acoustic Emission of Fresh "Malian Bones"

Abstract

In an extension of our previous work on bovine femora (1977 Ultrasonics Symp. Proc.), acoustic emission testinBhave been performed on bones from several different species of mammals and from different types of bone within the same species: canine skulls, femora, tibiae/fibulae, humeri, and ulnaqradii, porcine skulls and femora; and bovine tibiae and femora. Three types of acoustic emission (AE) parameters were obtained for each specimen: (1) cumulative AE counts vs. loading time, (2) number of AE events vs. pulse width, and (3) number of AE events vs. peak amplitude. The AE spectra from these bones are similar, somewhat independent of the s pecies of mammals and the type of bone, but different from those of other natural and synthetic materials. The surrounding soft tissues in canine long bones appear to attenuate AE signals, thus lowering the number of AE events in both pulse width and amplitude distributions, compared to bones without soft tissues. However, effects of the soft t issues in canine skulls seem to be insignificant. In order to simulate abnormal or defective bones, a drilled hole or EDTA treatment was introduced into the specimen.