Numerical Analysis Of Bone Remodeling Under Multi Field Coupling Load

It is recognized that living bone is continually undergoing processes of growth, reinforcement and resorption termed"remodeling"under internal or/and external loads. These remodeling processes are the mechanisms by which bone adapts its histological structure to changes in long term loading. Generally, there are two kinds of bone remodeling: internal and surface (Frost, 1964). The distinction between them is as follows. Internal remodeling refers to the resorption or reinforcement of an existing bone by decreasing or increasing respectively, the bulk density of the bone within fixed external boundaries. Surface remodeling refers to the resorption or deposition of bone material on the external surface of the bone.The problem of internal remodeling of the bone is addressed within the framework of bone adaption theory. Three kinds of internal bone remodeling problems are analysed on the basis of bone adaption theory using finite element analysis method: (1) Internal remodeling of the bone which is seemed to be a kind of material without piezoelectricity (2) Internal remodeling of the bone which is seemed to be piezoelectricity material caused by mechanical load (3) Internal remodeling of the bone which is seemed to be piezoelectricity material caused by mechanical load and electricity load. A"node-based"finite element analysis and first-order Adams-Bashforth method is used here , not only to eliminate the checker-board phenomenon but also to improve the convergence speed. In the numerical analysis, various load and electrical conditions are considered.In the end gives an analysis of the effect of material character and the load conditions on internal bone remodeling behavior. The numerical results showed that both of the mechanical load and electric field can affect internal bone remodeling process and this feature may be utilized in controlling healing process of injured bones. It should be mentioned here that all the results are attained on the basis of the numerical model which may be different from remodeling process of actual bone materials. So further experimental verification is required before the proposed formulation can be applied to the medical clinical pratice. The model of this paper has some disadvantages, and we must try to find other better model to distinguish the respective effect of electricity load and mechanical load on the bone remodeling process.