Selection of the best element type in the finite element analysis of hip prostheses

Hip prostheses have to fulfil biomedical, anatomical and strength requirements. In the initial design phase it is convenient to carry out contact analyses that simulate standardized fatigue tests using automatically generated finite element meshes of the implant design. While parabolic tetrahedrons are known to be more accurate, they usually cannot be used in contact analyses. In the present study, a prototype design was analysed using automatically generated tetrahedral meshes under linearly equivalent boundary conditions. Results of convergence analyses show that linear tetrahedral elements, even with rotational degrees of freedom, should be avoided, especially when modelling regions with a high stress gradient.