Comparison Of Mechanical And AE Properties And Fracture Patterns Of Aged And Fresh Bovine Bone

PURPOSE: We performed compression tests on fresh and artificially aged specimens to compare differences in mechanical properties, AE parameters, and fracture patterns. METHODS: We artificially aged specimens by bleaching and boiling. Pre-test CT scans revealed aged specimen damage(Fig. 1). A narrow-band resonant acoustic emission sensor was mounted on the specimens. SUMMARY OF RESULTS: Fig. 2 shows force-displacement and AE energy-displacement curves. Aged specimens have stiffer responses and higher failure forces. AE activity started immediately and continued throughout the test for aged specimens. Early AE activity is likely due to pre-existing fractures. AE events in fresh specimens started near failure. Aged specimens had more AE events with higher energies and amplitudes. Fresh specimen AE events had higher average frequencies. Aged specimens had vertical and fragmentary fractures. Fresh specimens exhibited based buckling with fractures in radial and circumferential directions (Fig. 3). CONCLUSION: This study revealed different mechanical properties, acoustic emission parameters, and fracture patterns between fresh and aged specimens. The pre-existing fractures in aged specimens most likely contributed to the different behaviors.