THE MICROSTRUCTURAL ORIGINS OF ACOUSTIC EMISSION SIGNATURES ENCOUNTERED DURING FRACTURE CUTTING OF BOVINE CORTICAL BONE

This paper is aimed at studying the acoustic emission signatures of dominant failure mechanisms encountered during fracture cutting of bovine cortical bone. This is achieved through an orthogonal cutting study performed in a sensor-rich environment comprising of a cutting force sensor, acoustic emission sensor and a high-speed camera. The synchronization of these three sensing modalities allows for the visual identification of the dominant failure modes, while also mapping them to their corresponding acoustic and cutting force metrics. Given their distinctly different underlying microstructures, the haversian and plexiform components of the bovine cortical bone are investigated separately. A total of six dominant failure mechanisms have been confirmed across the haversian and plexiform bone types. Osteon fracture and trans-lamellar fracture have been identified as the mechanisms expending the maximum energy during the fracture cutting of haversian and plexiform bone, respectively. Overall, the acoustic emission and the cutting force metrics are seen to be complementary in characterizing the six failure mechanisms. The findings of this work have implications for tool-mounted sensing modalities that could be used to detect ‘in-process’ failure mechanisms during bone surgical procedures.