Micromechanical Analysis of the Trabecular Bone Stress State at the Interface with Metallic Biomedical Devices*

An iterative procedure for the stress analysis at interfaces between dissimilar materials is presented. The problem is specialised to the case of biomaterial interfaces with particular reference to materials which are characterised by tiny microstructures. The procedure is based on a recursive analysis of small size problems defined upon subdomains obtained by partitioning the whole structural domain. The kinematic boundary conditions are iteratively adjusted by using appropriate preconditioners. The numerical example reported in this paper shows that the procedure is effective regardless of the degree of material heterogeneity, in contrast with the results obtained by using a coarse mesh for the whole domain. The procedure seems to be a promising one for determining the structural strength of interfaces between trabecular bone and metal implants requiring accurate evaluation of stress at the scale level of the single microstructure exhibited by the bone.