Determinación de la tensión de rotura de huesos combinando ensayos mecánicos y microtomografía computarizada

Abstract

The determination of the load that a bone is capable of supporting can be measured experimentally, in principle, by means of a conventional tensile test. However, given the complex geometry of the bone and the difficulties in fixing it in a universal testing machine, direct measurement of the breaking stress itself is very difficult. These difficulties mean that the properties of these materials are often determined by means of 3-point bending tests. To determine the mechanical properties of bones by 3-point-bending tests requires knowledge not only of the loaddisplacement recorded during tests but also of the geometry of samples. In this work, a method has been proposed to determine the mechanical properties of bones by combining mechanical tests with micro-computed tomography techniques. In this work, a bio-mechanical test has been performed on a mouse bone whose geometry was previously known. Given the fragile nature of the bone, a linear-elastic behaviour until failure was assumed. Once the test had been carried out, the real maximum stress it has withstood was determined from the maximum load reached, using both classical theories of strength of beam materials and finite element techniques. As a result of this work, a comparison is shown between the results obtained using beam theory, which is easy to apply, and finite element models, which are more costly and complex to apply.