Application of Neural Network and Finite Element Method for Multiscale Prediction of Bone Fatigue Crack Growth in Cancellous Bone - Multiscale Computer Modeling in Biomechanics and Biomedical Engineering - page 21

Complete
trabecula
fracture

Fatigue
damage

Crack
propagation

crack initiation

Fig. 10 Contour of fatigue damage within a trabecular bone specimen (cycle = 1.E5,
r ¼ 110 MPa, BV = TV ¼ 26 : 2 %). The enlargement shows the location of a fatigue crack and
its corresponding initiation and propagation process

In Fig. 11 , an enlargement of the predicted fatigue damage contour is given and
compared with reported experimental results. Micro-CT images of trabecular bone
specimens were obtained at 10 lm resolution by Wang et al. [ 50 ] to measure the
fraction of damaged bone tissue and to capture localized regions of damage in
trabecular bone specimens (Fig. 11 b).
The predicted damage was found to be located in a limited number of tra-
beculae at low apparent stress levels during the first cycle stage. It can be seen that
the predicted damage contour of Fig. 11 a is qualitatively similar to the experi-
mental ones of Wang et al. [ 50 ]. Both results show that the damage is localized in
small areas of the bone. Such local damage generates local non-linearities. This is
in agreement with experiments by Dendorfer et al. [ 9 ]. The authors showed that