• This is the author's version of a work that was accepted for publication in Computational Materials Science.Changes resulting from the publishing process, such as peer review, editing, corrections, structural for- Micro-scale modelling of bovine cortical bone fracture: Analysis of crack propagation and microstructure using X-FEM Adel A. Abdel-Wahab, Angelo R. Maligno, and Vadim V. SilberschmidtWolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK Abstract Bone fracture susceptibility increased by factors such as bone loss, microstructure changes, and material properties variations. Therefore, investigation of the microstructure and material properties effect on the crack propagation and the global response at macro-scale level is of great importance. A non-uniform distribution of osteons in a cortical bone tissue results in a localization of deformation processes. Such localization can affect bone performance under external load and initiate fracture or assist its propagation. Once the fracture initiates, that distribution can play an important role on the crack propagation process at micro-scale level. Subsequently, the global response at macro-scale level could also be affected. In this study, a two-dimensional numerical (finite-element) fracture model for osteonal bovine cortical bone was developed with account for its microstructure using X-FEM. The topology of a transverse-radial cross section of a bovine cortical bone was captured with optical microscopy. The mechanical properties for the microstructural features of the cross-section were obtained with a use of the nanoindentation technique. Both the topology and nanoindentation data were used as input to the model formulated with the Abaqus 6.10 finite-element software. The area, directly reflecting micro-scale information, was embedded into the region with homogenised properties of the cortical bone. The simulations provide the macro-scale global response, crack propagation paths and the distribution of maximum principal stress fields at the micro-scale level for three different microscopic topologies; homogeneous, two phase composite model and threr phase composite model under tensile loading condition. The calculated stress fields for various cases of topologies demonstrate different patterns due to implementation of microstructural features in the finite-element model. There is an important role of the microstructure on the crack propagation trajectory. The suggested approach emphasizes the importance of microstructural features, especially cement lines, in development of bone failure.

No abstract

No abstract

No abstract

No abstract