Destruction simulation for the inhomogeneous body by finite element method using computed tomography data
Destruction simulation for the inhomogeneous body by finite element method using computed tomography data
复制标题
利用计算机断层扫描数据通过有限元法模拟非均质体的破坏
DOI：
10.15593/rjbiomech/2020.2.12
复制
发表时间：
2020
影响因子：
--
通讯作者：
O. Sachenkov
中科院分区：
文献类型：
--
作者：
Pavel Bolshakov;O. Sachenkov
这项工作致力于用有限元方法模拟骨器官的破坏，并考虑CT数据。为了验证模型的有效性，文中还给出了股骨的仿真结果。这种方法可以使器官的模拟个体化，并确定研究的相关性。用有限元方法进行了数值研究，采用了线性逼近的八节点有限元。考虑了非均匀弹性体的线性方程。杨氏模数和极限应力用幂函数确定。假设力学性能对光密度的依赖关系，而光密度又由依赖于Hounsfield数的线性关系确定。对于有限元方法的离散化，根据层析成像数据对每个单元的材料的力学性能进行分布。求解后，计算出各节点的应力应变状态安全系数。根据计算的安全系数，决定是加厚网格还是删除有限元。文中给出了用该方法对非均匀试件和平均力学性能试件两个问题的计算结果。这些问题的数值结果说明了器官应力-应变状态结果的显著差异，并使我们能够判断器官破坏的性质。
The work is devoted to modelling the bone organ destruction using the finite element method and taking into account the CT data. In order to evaluate the model, the simulation results for the femur are presented. Such an approach allows to individualize the simulation of the organ and determines the relevance of the study. Numerical studies using the finite element method were performed, an eight-node finite element with linear approximation was used. A linear formulation for an inhomogeneous elastic body was considered. Young’s modulus and ultimate stress were determined using power functions. The dependence of mechanical properties on the optical density was assumed, which, in turn, was determined by linear relationships depending on the Hounsfield numbers. For discretization by the finite element method, the distribution of the mechanical properties of the material for each element was performed according to tomography data. After solving, the stress-strain state problem safety factor was calculated in each node. Based on the calculated safety factor, a decision is made either to thicken the mesh or to remove the finite element. The paper presents the results of calculations using the method for two problems: an inhomogeneous sample and specimen with averaged mechanical properties. The numerical results in these problems illustrate the significant differences in the results of the stress-strain state of the organ and allow us to judge the nature of the destruction of the organ.