Creep contributes to the fatigue behavior of bovine trabecular bone.

摘要: Repetitive, low-intensity loading from normal daily activities can generate fatigue damage in trabecular bone, a potential cause of spontaneous fractures the hip and spine. Finite element models bone (Guo et al., 1994) suggest that both creep slow crack growth contribute to failure. In an effort characterize these mechanisms experimentally, we conducted tests on 85 waisted specimens obtained 76 bovine proximal tibiae. All applied stresses were normalized by previously measured specimen modulus. Fatigue at room temperature; 4, 15, 25, 37, 45, 53 degrees C custom-designed apparatus. The behavior was characterized decreasing modulus increasing hysteresis prior loops progressively displaced along strain axis, indicating also involved process. three classical stages decreasing, constant, rates. Strong highly significant power-law relationships found between cycles-to-failure, time-to-failure, steady-state rate, loads. Creep analyses generated strong power law for time-to-failure rate. Lastly, products rate constant equal failure strains, suggesting plays fundamental role bone. Additional analysis data suggests are not separate processes dominate high low loads, respectively, but present throughout all fatigue.