Research Of The Mechanics Model Of Bone Scaffold

Artificial bone scaffolds are the most promising substitute materials for bone repair. In this paper, we have investigated mechanical properties of bio-derived bone scaffolds and built mechanical models for their structural and mechanical properties on a frame of human bone microstructure. These models have been evaluated by numerical simulation and experimental studies that define their mechanical parameters. We have also investigated the mechanical properties of porous metal materials and porous coating materials. Main results are summarized as follows:1. Cortical bone of the prepared bio-derived bone is made up of punched bone plates. The cancellous bone forms a plexiform structure when it is close to cortical bone and forms a network structure when it is away from cortical bone. In damage study, cortical bone of the fabricated bio-derived bone is cracked along the circumferential direction, and the lateral wall of cancellous bone is disrupted first.2. A method is proposed to build a model of bone scaffold mechanics that represents the normal human bone structure and mechanical properties. Using this method, we have built a model of radius bone scaffold mechanics and a model of bio-derived bone scaffold mechanics that describe three dimensional structure and mechanical behaviors of normal human bones. The relationship between shear modulus and time has been found.3. Simulation studies of these two bone scaffold mechanical models suggested that the maximum stress is on lateral holes of the pore wall that would damage the lateral wall first. The relationship between stress and strain is of non-linear viscoelasticity. The integral stiffness of bone scaffold materials was obtained by means of linear fitting.4. Finite element models of mechanics were built for porous copper - aluminum - aluminum composite material and for randomly generated porous titanium / HA composite coating material, respectively. Finite element simulation and analyis of porous copper - aluminum - aluminum composite material suggested a relationship between shear modulus and time, with the elastic modulus comparable to the experimental data. Both the relationship between pressure and displacement and the relationship between support reaction and time were of non-linear viscoelasticity. Finite element simulation and analysis of porous titanium / HA composite coating material suggested a relationship of equivalent elastic modulus with porosity, and of solid fractal dimension with porous fractal dimension. It also suggested a range of porosity and of pore/solid fractal dimension in the porous titanium alloy/HA bone scaffold material that best conforms to the requirements of natural bone mechanical properties.