复合结构人工骨支架微结构的设计研究

发布时间：2018-03-05 00:03

本文选题：组织工程支架　切入点：微孔结构　出处：《新疆大学》2015年硕士论文　论文类型：学位论文

【摘要】：组织工程骨支架的结构决定着仿生人工骨的成骨性能,因此支架不仅需要三维微孔结构且需要有足够的强度。针对支架需要足够的孔隙率和足够的强度的需求,本文进行了研究。利用有限元分析软件,对人工骨支架的微孔结构对支架应力、应变和变形的影响,进行了数值模拟研究。同时利用力学压缩实验对人工骨支架结构的力学性能进行验证分析。对单一材料生物陶瓷β-磷酸三钙(β-TCP)人工骨支架内部的微孔结构进行优化设计。利用ANYSY软件建立支架微孔结构的三维模型,三维模型赋予其边界条件、载荷条件、材料参数,进行网格划分。然后定义变化参数及参数范围,对其进行优化分析,计算得到模型的最大等效应力及最大总变形与孔隙率的关系,并分析比较不同孔径、孔间距结构对支架最大等效应力、最大总变形、内部应变的影响。支架孔隙率和最佳应变比越大,最大等效应力、最大总变形越小,支架生物性能和力学性能越好。分析得到了微孔各个参数对支架孔隙率、最大等效应力、最大总变形以及内部应变的影响规律,这些结果为支架的结构设计和优化提供了有意义的参考价值。为复合结构中钛合金TC4支架结构的分布作前期研究,对钛合金支架进行了优化设计。建立钛合金支架各个方向不同层数和不同直径的钛合金支架模型,对其进行有限元分析,提取支架的最大等效应力和最大总变形。同时利用激光选区熔化技术(Selective Laser Melting,SLM)制备钛合金支架结构,利用力学实验对模拟仿真的结果进行验证。结果显示增加Z轴方向钛合金直径和X轴方向钛合金层数时,更有利于提高支架的力学性能。对生物陶瓷-钛合金复合结构人工骨支架的内部结构的进行了设计,并对复合结构中钛合金支架结构的分布和直径对支架力学性能的影响进行了研究与分析。利用ANYSY软件建立钛合金的分布和直径的不同的复合支架结构有限元模型,计算支架最大等效应力、最大总变形。本章计算结果显示复合结构中钛合金支架结构的受力面积越大,支架最大等效应力、最大总变形越小,支架生物性能和力学性能越好。分析得到了钛合金支架结构各个参数对支架最大等效应力、最大总变形的影响规律,这些结果为支架的结构设计和优化提供了有意义的参考价值。
[Abstract]:The structure of tissue engineered bone scaffolds determines the osteogenic properties of biomimetic artificial bones, so the scaffolds need not only three-dimensional microporous structures but also sufficient strength. In this paper, the effect of micropore structure on stress, strain and deformation of artificial bone scaffold was studied by using finite element analysis software. At the same time, the mechanical properties of the artificial bone scaffold were verified and analyzed by mechanical compression experiment. The micropore structure of the single material bioceramics 尾 -TCP-based artificial bone scaffold was optimized. Using ANYSY software to build three-dimensional model of scaffold micropore structure, The 3D model gives it boundary conditions, load conditions, material parameters, meshes, and then defines the variation parameters and parameter ranges, and analyzes them optimally. The relationship between the maximum equivalent stress and the maximum total deformation of the model and the porosity is obtained, and the maximum equivalent stress and the maximum total deformation of the support with different pore sizes and pore spacing structures are analyzed and compared. The larger the porosity and the optimum strain ratio, the greater the maximum equivalent stress, the smaller the maximum total deformation, the better the biomechanical and mechanical properties of the scaffold. The maximum total deformation and the influence of internal strain provide a significant reference value for the structural design and optimization of the support, and provide a preliminary study for the distribution of titanium alloy TC4 scaffold structures in composite structures. The optimal design of titanium alloy bracket was carried out. The model of titanium alloy stent with different layers and diameters in different directions was established, and the finite element analysis was carried out. The maximum equivalent stress and total deformation of the scaffold were extracted. At the same time, the titanium alloy scaffold structure was prepared by laser selective Laser melting technique. The simulation results are verified by mechanical experiments. The results show that when the diameter of Z axis titanium alloy and the number of X axis titanium alloy layers are increased, The internal structure of the scaffold with bioceramic-titanium alloy composite structure was designed. The influence of the distribution and diameter of titanium alloy bracket structure on the mechanical properties of the composite structure was studied and analyzed. The finite element model of titanium alloy composite scaffold structure with different distributions and diameters was established by using ANYSY software. In this chapter, the results show that the larger the bearing area of titanium alloy bracket, the smaller the maximum equivalent stress and the smaller the total deformation. The better the biomechanical and mechanical properties of the scaffolds are, the influence of the parameters of the titanium alloy scaffolds on the maximum equivalent stress and the maximum total deformation of the scaffolds are obtained. These results provide a valuable reference for the structural design and optimization of the scaffold.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R318.17;R687

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