Estimation of Fatigue life of Cortical Bone Considering Viscoelastic Properties and Damage Mechanics

Recently, the Osteoporosis victims increase in the senior citizen. Therefore, the danger of the stress fracture due to the decrease in bone strength is pointed out. Especially, the damage accumulation behavior of the bone in the cyclic load becomes a problem for the fatigue of the bone. Moreover, it is necessary to consider the viscoelastic property for the prediction of the fatigue behavior, because the bone is a viscoelastic material. In this study, our objective is to estimate the fatigue behavior that considers the viscoelasticity behavior and the damage accumulation behavior as damage mechanics. The viscoelastic properties were revealed with the strain rate tests, and we calculated the 3-mode Maxwell parameters with these results. The damage accumulation behaviors were measured with the Acoustic Emission method. Using these results, we could estimate the fatigue behavior of cortical bone with the viscoelastic parameter and cumulative AE energy.