Abstract
Damage accumulation in bovine cortical bone under cyclic loading was characterized by AE monitoring and ultrasonic wave velocity measurement. Static and fatigue compression tests were performed and microfracture process was investigated by AE technique. In static test, remarkable AE increase was observed only at final fracture, while continuous AE activity was observed during fatigue test. Longitudinal wave velocity along radial axis of the bone decreased gradually during fatigue loading. Furthermore, the AE signals corresponding crack opening and closure were discriminated. Comparing the AE behaviors during static and fatigue tests, and decrease in wave velocity during fatigue test, it was understood that the crack opening AE emitted from crack propagation and crack closure AE has dominant role for degradation of strength of bone under cyclic loading.
