| This work is concerned with the development and verification of a methodology for a reliable prediction of risk of radius fracture in the event of a fall onto an outstretched hand. The proposed approach involves inelastic finite element analysis, which incorporates comprehensive information on bone geometry, material properties of bone tissue and strength characteristics.In the second part of this work, a two-stage experimental program is described. This program was aimed at examining the process of initiation/propagation of fracture in human radii under conditions simulating a fall onto an outstretched hand. The experimental results provided a benchmark for assessing the predictive abilities of numerical models incorporating linear/non-linear finite element formulations. In addition, key information about mechanical properties of bone tissue was obtained. The latter results were used to verify the performance of an anisotropic fracture criterion for cortical tissue.The last part of the thesis is focused on numerical analysis of fracture initiation and propagation. First, the procedure for generation of FE mesh for a radius bone is described. Subsequently, the implementation of the mathematical formulation in finite element software is discussed, followed by verification problems. Finally, inelastic finite element analyses simulating the actual experimental tests designed to produce a Colles' fracture are presented and their outcome compared against the experimental results.In the first part, main aspects of the proposed methodology are discussed. The primary focus is on the macroscopic description of propagation of fracture within the cortical tissue. The inception of fracture is defined by invoking a criterion based on the critical plane approach, which takes into account the anisotropic nature of bone tissue. The subsequent propagation of damage is described by employing a homogenization procedure and incorporating the framework of associated plasticity. |
