摘要
目的:构建基于Micro CT的大鼠胫骨三维有限元模型,通过有限元分析计算得到在轴向压缩载荷作用下的胫骨表面应变的空间分布。方法:将Micro CT扫描得到的断层图像通过Mimics、Geomagic Studio和Solidworks软件建立大鼠胫骨的三维实体模型,导入ABAQUS 6.14中,将胫骨简化成各向同性材料,采用四面体单元划分网格,边界条件定义为胫骨远端固定、近端施加轴向载荷,经有限元分析计算得到胫骨表面应变的空间分布及"应变-载荷"关系曲线,并基于此确定胫骨表面最大张应变和压应变的解剖位置。结果:对大鼠胫骨的有限元分析计算发现,施加载荷与应变之间存在着显著的线性正相关关系;通过对不同载荷下大鼠胫骨表面应变空间分布的分析显示,最大张应变发生在胫骨近中下1/3处,最大压应变发生在胫骨中段。结论:基于Micro CT的三维有限元分析方法可以成功建立大鼠胫骨轴向的应力载荷加载模型,并可通过该方法精确定量不同压缩载荷作用下的胫骨表面张应变和压应变的空间分布,为预测骨微损伤发生的空间位置分布提供理论支撑。胫骨骨微损伤发生风险最高部位为胫骨中段及近中下1/3处。该模型可为课题组骨微损伤的动物和临床实验研究奠定重要基础。
Objective To establish a Micro CT-based 3D finite element analysis（FEA） model of rat tibia and obtain the spatial distribution of strain on rat tibia surface under axial mechanical loading via the FEA calculation.Methods Tomographic slices of the rat tibia were scanned by Micro CT and then imported into the Mimics,Geomagic Studio and Solidworks software to establish a 3D solid model.Then,the 3D model was imported into ABAQUS 6.14.The model was simplified as an isotropic material,and tetrahedron was used to mesh the model,and finally the boundary condition was defined.The distal part was fixed,while the proximal end was free to translate in the axial displacement.The 3D strain map of rat tibia surface together with the ＇stain-load＇ curve was obtained.Based on these results,the anatomical position with maximal tensile stain and compressive stain on the tibia surface were identified.Results The FEA results of the rat tibia demonstrated that a significant linear positive correlation between the load and strain was observed.The analysis results for the strain spatial distribution suggested that the maximal tensile strain occurred at distal 1/3 and maximal compressive strain occurred at mid-shaft of the tibia.Conclusion It′s demonstrated that the Micro CT-based finite element analysis method can successfully establish axial mechanical loading model on the rat tibia,and can identify the position with maximal tensile stain and maximal compressive stain on the tibia surface.This model may provide a critical theoretical basis for the skeletal microdamage study.It＇s shown that distal 1/3 and mid-shaft of the tibia might have the highest risk for the occurrence of microdamange.This model provides important foundation for the succeeding experimental and clinical investigations in bone microdamage.
出处
《医疗卫生装备》
CAS
2016年第11期15-18,31,共5页
Chinese Medical Equipment Journal
基金
国家自然科学基金资助项目(31500760)
