Computational Modeling in Bone Machining

Abstract

In general machining of materials is a complex process involving several process and material parameters. During machining, multiple physical phenomena are associated with combination of these process and material parameters. These physical phenomenon may occur simultaneously or in sequence rendering the process of machining very complex. The complexity of machining further depends upon the type of machining process and the nature of material being machined. Especially, in case of bone, as described in Chap. 1, which is a multicomponent, multi-composition, and hierarchical material that in turn makes its interaction with a machining tool (mechanical or heat based) very complicated. To understand such interaction and involved physical phenomena during bone machining is very important to control the machining process for desired outcome. However, inherently complex nature of bone machining renders it to inability for in-situ probing of the physical phenomena employing any experimental techniques. In view of this, either numerical or analytical computational modeling appears to be a suitable approach in designing a bone machining process for desired outcome. Nonetheless, due to the complex nature of bone machining, the search of open literature revealed paucity of efforts on computational modeling. Only limited efforts were focused on heat transfer and stress based computational modeling. Furthermore, some of the efforts have also tried to model micro scaled mechanics in bone. Hence, the current chapter is divided in to three sections; heat transfer model, stress based models, and micro scaled models. Key equations and process parameters in each case have been elaborated. Important studies concerning all these aspects have been discussed. Heat Transfer ModelsPrediction of heat transfer during bone machining process aids in optimization of the operation intended to minimize the damage by thermal necrosis. Basic equation governing the heat transfer (Eq. 6.1) within the bone forms the foundation of thermal finite element model (FEMs).

Non-Fourier bioheat model for bone grinding with application to skull base neurosurgery

“…It is assumed that all the frictional and shear energy of the contact area is converted to heat flux, and this flux is also represented by the heat source for the analytical solution. Using the formulas from machining theory, shear velocity, Ernst-Merchant relationship, and frictional force and previous studies, 6,25,26 the final expression is obtained. Heat-based machining methods are like laser processing.…”