方形孔结构细胞支架非线性流固耦合数值计算

Numerical computation on the scaffolds models with regular square holes using nonlinear fluid-solid-coupling approaches

目的讨论三维方形孔细胞支架不同孔隙率和不同孔半径的对细胞表面固体场和流体场的影响,以及将多孔支架视为刚性体和非线性变形体对计算结果的影响。方法采用一种直接耦合解法和和两种间接耦合解法,两种间接耦合解法分别是有限原法(固体模型)与有限差分法(流体模型)耦合、有限原法(固体模型)与有限体积法(流体模型)耦合。对3种流固耦合计算方法的可靠性进行验证。结果通过对构建的12种模型的计算(50、100和150μm三种边长和61%、65%、77%和84%四种孔隙率),获得了固体模型的应力场、应变场和位移场和流体模型的静压、速度、壁面剪应力和切变率,并对结果进行了比较分析。结论将多孔支架视为刚性体和非线性变形体计算结果有一定差别;孔隙率一定时不同孔半径以及孔半径一定时不同孔隙率条件下对固体场和流体场都有不同程度的影响。

Objective The influencing parameters of solid and fluid computing fields for the scaffolds models with regular square holes were discussed by nonlinear fluid-solid-coupling approaches.The numerical computational results of which the models were regarded as both rigid body and non-linear elasticity were compared as well.Method One direct fluid-solid-coupling approach and two indirect fluid-solid-coupling approaches were adopted,and the calculating reliability of three kinds of fluid-solid coupling methods was verified.Results The solid-fluid-coupling computational results are obtained in light of 12 kinds of scaffolds models which are constructed by 3 groups of square side length（50,100 and 150 μm）and 4 groups of porosity（61%,65%,77% and 84%）.The field parameters of those solid models including stress,strain and displacement and those fluid models including static pressure,velocity,wall shear stress and strain rate are achieved and compared.Conclusion There appear some difference between the results of porous scaffold models as a rigid body and as non-linear elasticity.The different porosity with the same pore radius or the different pore radius with the same porosity would affect the field parameters of solid models and fluid models in varying degrees.