A simulation study of artificial bone scaffolds based on multi-physics coupling model

Through establishing the fully coupling mathematical model of the fluid-structure of the artificial bone scaffolds under the saturated porous medium and using finite element method, we analyze the stress, strain trends of the artificial bone scaffolds under several load constraints so that we can predict the biodegradation and regeneration of the artificial bone scaffolds under optimization growth situations. We demonstrated the stress equation in multi-physics according to the mechanical equilibrium condition, and established the dynamic coefficient model of porosity (Eq. 6) and permeability (Eq. 11) in Section 2. Section 3 describes seepage dynamical equation deduction procedure and Eq. 21 is the dynamical seepage equation. Meanwhile, based on the hydromechanics continuity equation and considering the deformation of the skeleton and the compressibility of the fluid, we obtained the full fluid flow constitutive equation (Eq. 30) in Section 4. We put Eq. 21 into COMSOL simulation platform as the seepage governing equation and input Eq. 30 as constitutive equation. In addition, in Section 5.1 we put forward the initial and constraint conditions. We then analyzed the distributed rule between stresses, displacement under interstitial fluid flow pressure based on this fluid-structure coupling seepage theory. Figs. 4 and 5 demonstrate that the density of nutrition fluid flow and bone scaffolds increases with the external loads and interstitial fluid flow pressure; Fig. 6 demonstrates that the seepage velocity of nutrition fluid flow increases sharply with the depth of bone scaffolds; Figs. 7 and 8 show that the coupling stress is bigger than the non-coupling stress; Fig. 9 shows that the nutrition fluid flow velocity increases with bone scaffolds porosity.