采用有限元方法建立和分析枢椎的生物力学行为

发布时间：2018-05-14 14:14

本文选题：枢椎 + 有限元　；参考：《安徽医科大学》2012年硕士论文

【摘要】：背景在科学技术领域内,对于许多力学问题,由于方程某些特征的非线性性质,或由于求解区域的集合形状比较复杂,不能得到解析的答案。对于这类问题人们通常采用数值解的方法,但是,随着计算机的应用,数值分析方法已成成为求解科学技术问题的主要工具。在已有的数值分析方法中,有限单元法是一种十分有力的求解工具。它对于其他数值分析发放来说,可以对几何形状十分复杂的问题进行求解。它的出现是数值分析方法研究领域内重大的突破性进展。有限单元法是随着电子计算机的发展而迅速发展起来的一种现代计算机发放。它是20世纪50年代首先在连续体力学领域—飞机机构静、动态特性分析中应用的一种有效的数值分析方法,随后很快被广泛地应用于求解热传导、电磁场、流体力学等连续性问题。有限元法的基本思想是连续的求解区域离散为一组有限个、按一定方式相互连接在一起的单元的组合体。由于单元能按不同的连结方式进行组合,且单元本身又可以有不同的形状,因此可以模型化几何形状复杂的求解域；有限元的另外一个重要特点是利用在每个单元内假设的近似函数来分片地表示全求解域上待求的未知场函数,从而得到整个求解域上的近似解。本研究就是采用有限元方法建立和分析人类枢椎的生物力学行为。目的采取有限元的方法,建立第二颈椎(枢椎)的三维有限元模型,模拟该枢椎模型在外力作用下的生物力学行为,分析枢椎骨折的生物力学条件。方法利用螺旋C T扫描获得1例健康成年男性上颈椎原始DICOM数据图像,采用Mimics软件对数据进行处理并导入ANSYS软件,得到枢椎骨性结构的三维实体模型。并且此模型上模拟头颅位于中立位、屈曲位及后伸位等条件下,枢椎承受的应力分布状况,分析枢椎可能出现的骨折类型。结果实验所构建枢椎骨性的有限元模型外形逼真,三维网格化后枢椎模型共包含1717个节点,5772个单元。模拟结果：头颅在中立、前屈、后伸位时枢椎最大应力集中于齿突基底部,次级应力集中区域为枢椎椎弓峡部；直接于齿突加载力模拟头部过度屈曲时,最大应力集中于齿突基底部。结论头颅为于中立位,屈曲位或者后伸位,枢椎齿突基底部及枢椎椎弓峡部是应力最集中的部位。头部过度屈曲时,齿突基底部是应力最集中的部位。
[Abstract]:Background in the field of science and technology, for many mechanical problems, because of the nonlinear properties of some characteristics of the equation, or because of the complexity of the shape of the set of solving regions, we can not get an analytical answer. Numerical methods are usually used to solve this kind of problems. However, with the application of computer, numerical analysis has become the main tool for solving scientific and technological problems. Finite element method (FEM) is a powerful tool for numerical analysis. For other numerical analysis, it can solve the problem with very complicated geometry. Its emergence is an important breakthrough in the field of numerical analysis. Finite element method (FEM) is a kind of modern computer distribution developed rapidly with the development of computer. It is an effective numerical analysis method which was first applied in the field of continuous mechanics in 1950s, which is the static and dynamic characteristics analysis of aircraft mechanism, and then it is widely used to solve heat conduction and electromagnetic field. Continuity problems such as hydrodynamics. The basic idea of finite element method (FEM) is to discretize the solution region into a finite group of units connected with each other in a certain way. Because the element can be combined according to different connecting modes and the element itself can have different shapes, the complex solution domain of geometric shape can be modeled. Another important feature of the finite element is that the approximate function assumed in each element is used to represent the unknown field function in the whole solution domain in a piecewise manner, and the approximate solution on the whole solution domain is obtained. The purpose of this study is to establish and analyze the biomechanical behavior of human axis by finite element method. Objective to establish a three-dimensional finite element model of the second cervical vertebra (axis) by finite element method, simulate the biomechanical behavior of the axial model under external force, and analyze the biomechanical conditions of the axial fracture. Methods the original DICOM images of a healthy adult male upper cervical vertebra were obtained by spiral CT scanning. The data were processed by Mimics software and imported into ANSYS software. The three-dimensional solid model of the axial bone structure was obtained. In this model, the stress distribution of the axis is simulated under the condition of neutral position, flexion position and extension position, and the possible fracture types of the axis are analyzed. Results the finite element model of axial bone was constructed in our laboratory. The 3D mesh model consisted of 1717 nodes and 5772 elements. The results showed that the axial maximum stress was concentrated at the base of odontoid base in neutral, anterior flexion and extension position, and the secondary stress concentration was in the isthmus of axial arch, and when the dentoid loading force was used to simulate the overflexion of the head, the maximum stress was concentrated in the base of odontoid process. The maximum stress is concentrated at the base of the dentate process. Conclusion the skull is in neutral position, flexion position or extension position, the base of odontoid process of axis and the isthmus of pedicle of axis are the most concentrated part of stress. When the head is overflexion, the base of odontoid is the most concentrated part.
【学位授予单位】：安徽医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R687.3;R318.0

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