Finite element analysis of macro-crack behavior in the cortical bone of a human tibia

The bone is a biological tissue that possesses a highly complicated hierarchical structure; hence, the tissue components of the bone exhibit variable mechanical properties and a complex bone geometry. This is why the creation of a three-dimensional model through CAD software facilitates the study of the mechanical behavior of bones. Combining the concepts of linear elastic fracture mechanics and finite element analysis provides a practical solution to study the fracture behavior of the tibial bone. The objective of this study is to analyze the behavior of cracks in the cortical bone of the human tibia using stress intensity factors (SIF) in mode I, II, and III as rupture criteria to assess the bone damage response. The tibial bone is one of the most common sites for lower limb stress fractures, which pose problematic injuries. The results investigating the effect of the crack position in the bone demonstrate that the risk of crack propagation is mainly due to mode I opening and is highly favored in the distal zone compared to the middle and proximal regions, regardless of bone density. For the second case study, it is observed that regardless of the crack size, the maximum values of SIF KI are obtained in the distal zone. Regarding the effect of crack orientation, the results indicate the dominance of mode II for angles α = - 45°, 30°, 45°, leading to high values of SIF KII.