单枚外固定支架螺钉的三维有限元模型的初步建立及应用

Reconstruction and application of three dimensional finite element analysis model of single external fixation screw

目的建立单枚外固定支架螺钉钻入胫骨干的三维有限元模型。方法运用Pro/E,Geomagic Studio工程软件,Ansys Workbench13建立胫骨三维皮质螺钉装配体的有限元模型,并施加轴向载荷观察结果。结果胫骨干生成1217个体网格,螺钉生成270个体网格,应力云图显示螺钉的最大应力位于螺钉与皮质骨接触处,形变最明显的位置处于螺钉尾部。试验中通过对螺钉加载不同载荷,测量分析,得出螺钉最大应力及螺钉总变形量与轴向载荷呈正相关(线性关系)。结论三维胫骨螺钉装配体有限元为后期的不同材质螺钉,不同负荷螺钉与胫骨皮质应力的定量分析研究提供依据,从而为筛选出适宜的外固定支架螺钉材质实现手拧自攻螺钉创造条件。

Objective To establish three dimensional FEA(Finite Element Analysis)model for drilling a tibial shaft with a single external fixation screw.Methods To use the software of Pro/E Geomagic Studio to set up FEA model of tibia-screw assembly successfully using Ansys Workbench13,observing results after applying pressure loads.Results The shaft of tibia and single external fixation screw had been generated1217and270volume meshes respectively,von-mises stress revealed the maxium stress of the screw was located at contact surface,the most obvious position of deformation was at the end of the screw.In the test,different loads were applied to the screws,and the measurement and analysis showed that the maximum screw stress and the total screw deformation were positively correlated with the axial load(linear relationship).Conclusion Three dimensional tibia-screw assembly model would provide theoretical basis for quantitative studies of stresses between different materials,loads and tibia shaft,may contribute to select appropriate material fixation self-tapping screws to drill by hand possibly.