镁合金骨板组织液流场分析及表面织构优化

发布时间：2018-04-23 11:08

本文选题：镁合金骨板 + 流场分析　；参考：《济南大学》2016年硕士论文

【摘要】：目前临床主要应用的固定植入体是不锈钢和钛合金骨板。这些骨板虽然能促进骨愈合,起到加强内固定的作用,但是会给患者带来负重感和二次手术的伤害。而镁合金骨板密度和人体骨相近,镁元素能被人体吸收,促进骨骼生长,无负重感,减少二次手术的伤害。故本文通过对镁合金骨板与断骨之间流场进行分析,研究携带药物的组织液的流动状态及分布规律,研究镁合金骨板表面不同织构型式对组织液流动状态的影响。通过有无织构的组织液流场分析,对织构的结构进行设计和优化。经过分析与计算,设计截面为正方形、半圆形、正六边形凹坑的三种镁合金骨板表面织构。通过在镁合金骨板表面添加织构,增加镁合金骨板与胫骨组织的接触面积,同时增大镁合金骨板表面的载药量。对镁合金骨板表面流场进行数学建模,通过对流场的速度、压力、剪切应力的计算与分析,为镁合金骨板表面织构优化与分析打下坚实基础。本文分析镁合金骨板表面组织液与药物组成的两相流的流场分析。通过正方形、半球形、正六边形三种单织构的骨板流场与无织构骨板流场两相流的比较分析,得出有表面织构的镁合金骨板流场的速度、压力、剪切应力较大,能促进骨骼愈合。而三种单织构的流场中,半球形织构的镁合金骨板更能促进人体骨骼愈合的速度。单织构流场的分析为镁合金表面织构的优化打下坚实的基础。通过比较分析镁合金骨板表面单织构的半球形流场与多织构的半球形流场发现,多织构流场与单织构流场差别不大,对有限元分析结果与数值计算结果进行相互对比,得出误差在允许范围内,说明半球形织构应用到镁合金骨板上是合理的。把组织液与药物看成一种流场,对镁合金骨板表面的半球形织构进行流场分析。通过改变半球形织构的深-径比来优化半球形织构,分析改变深-径比后的半球形流场,对流场的速度、剪切应力、压力进行分析比较,把有限元分析的结果与数值计算结果进行对比,误差在允许的范围内,得出深-径比为1:2的半球形织构更能促进骨骼的生长与人体康复速度。通过流-固耦合分析,得出镁合金骨板添加表面织构满足强度要求。
[Abstract]:The main clinical implants are stainless steel and titanium alloy bone plates. These plates, while promoting bone healing and strengthening internal fixation, can cause weight-bearing and secondary surgery injuries to patients. The density of magnesium alloy bone plate is similar to that of human bone. Magnesium element can be absorbed by human body, promote bone growth, have no sense of weight, and reduce the injury of secondary operation. Therefore, the flow field between magnesium alloy bone plate and broken bone is analyzed in this paper, and the flow state and distribution of tissue liquid carrying medicine are studied, and the influence of different texture types on the flow state of magnesium alloy bone plate is studied. The texture structure was designed and optimized by analyzing the flow field of tissue liquid with or without texture. Through analysis and calculation, the surface texture of magnesium alloy bone plate with square, semicircular and hexagonal pits is designed. By adding texture to the surface of magnesium alloy bone plate, the contact area between magnesium alloy bone plate and tibial tissue was increased, and the amount of drug loaded on the surface of magnesium alloy bone plate was increased. The flow field on the surface of magnesium alloy bone plate was modeled. The calculation and analysis of the velocity, pressure and shear stress of the flow field laid a solid foundation for the optimization and analysis of the surface texture of magnesium alloy bone plate. In this paper, the flow field of the two-phase flow on the surface of magnesium alloy bone plate is analyzed. By comparing and analyzing the flow field of bone plate with square, hemispherical and hexagonal single texture and that of non-texture bone plate, the velocity, pressure and shear stress of the flow field of magnesium alloy bone plate with surface texture are obtained. Can promote bone healing. In the flow field of three kinds of single texture, the magnesium alloy bone plate with hemispherical texture can promote the speed of bone healing. The analysis of single texture flow field lays a solid foundation for the optimization of magnesium alloy surface texture. By comparing and analyzing the hemispherical flow field of single texture on the surface of magnesium alloy bone plate and the hemispherical flow field of multi-texture, it is found that there is little difference between multi-texture flow field and single-texture flow field. The finite element analysis results are compared with the numerical results. The error is within the allowable range, which indicates that the hemispherical texture applied to the magnesium alloy bone plate is reasonable. The flow field of the hemispherical texture on the surface of magnesium alloy bone plate was analyzed by considering the tissue fluid and the drug as a flow field. The hemispherical texture is optimized by changing the ratio of depth to diameter of hemispherical texture, and the velocity, shear stress and pressure of the hemispherical flow field, the velocity of the flow field, the shear stress and the pressure of the hemispherical flow field after changing the depth-diameter ratio are analyzed and compared. Comparing the results of finite element analysis with numerical results, the error is within the allowable range, and it is concluded that the hemispherical texture with the ratio of depth to diameter of 1:2 can promote the growth of bone and the recovery speed of human body. Through fluid-solid coupling analysis, it is concluded that the surface texture of magnesium alloy bone plate can meet the strength requirement.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R687;R318.08

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