| Finite element models (FEM) are increasingly being used to investigate the mechanical behavior and the resistance of vertebrae. Nevertheless, biological variability (including age effects) and dynamic loading are not always taken into account when developing these models, in spite of their influence on the behavior of this structure.;The objective of this work was to integrate age related features in FEM of vertebrae in dynamic conditions.;The experimental part of this work consisted in testing vertebral bodies in compression at 0,5m/s. The data required to understand the failure mechanism of vertebral bodies and to validate FEM were gathered. The vertebrae were also scanned to evaluate their density.;The numerical part was divided into three sections:;First, the mechanical properties of trabecular and cortical bone were calibrated by using an inverse method in a FEM of a lumbar vertebra tested in compression at different loading rates.;Secondly, age effects were implemented in these calibrated models. Mechanical properties of bone components were adapted and validated according to literature data.;Finally, subject-specific models were developed from scans of the experimental part. Their responses, compared to experimental data, showed the efficiency of these models to evaluate quantitative (force, stiffness, energy) and qualitative data (location of the fracture initiation) in dynamic loading.;The results of this work have large prospects, from age effects influence on spine trauma to evaluation of surgery techniques considering subject-specific properties.;Keywords : Biomechanics, finite elements, bone, vertebra, mechanical properties, experimental tests, fracture, age, dynamics... |
