Technical note: Exploring acoustic emission characteristics from quasistatic compression testing of aged and fresh bovine cortical bone

Bone specimens are preserved using various methods, which have been shown to influence their material properties. An unexplored process of assessing the influence of preservation methods is using acoustic emission (AE) monitoring during quasistatic compression testing. AEs are transient ultrasonic waves generated during abrupt, localized plastic deformation. AE waveforms were collected and assessed for specimens preserved with two methods: fresh frozen and aged by boiling and bleaching. Results demonstrated that aged specimens exhibit different AE characteristics compared to fresh specimens, including an earlier onset of microcracking, higher AE event counts, and greater AE amplitudes and energies. Aged specimens generally showed a mix of tensile and shear microcracks, while fresh specimens predominantly exhibited shear microcracks. This study highlights the influence of preservation methods on the AE characteristics of bone tested in compression, providing valuable insight into the differences in microcracking phenomena between fresh and aged specimens.