  Bone is a multiscale heterogeneous materiel of which principal function is to
support the body structure and to resist mechanical loading and fractures. Bone
strength does not depend only on the quantity and quality of bone which is
characterized by the geometry and the shape of bones but also on the mechanical
proprieties of its compounds, which have a significant influence on its
deformation and failure. This work aim to use a 3D nano-scale finite element
model coupled to the concept of quasi-brittle damage with the behaviour law
isotropic elasticity to investigate the fracture behaviour of composite
materiel collagen-mineral (mineralized collagen microfibril). Fracture
stress-number of cross-links and damping capacity-number of cross-links curves
were obtained under tensile loading conditions at different densities of the
mineral phase. The obtained results show that number of cross-links as well as
the density of mineral has an important influence on the strength of
microfibrils which in turn clarify the bone fracture at macro-scale.
