中国人体50百分位小腿有限元模型开发及骨折特性研究

发布时间：2018-03-15 06:18

本文选题：建模方法　切入点：中国50百分位　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：在汽车碰撞安全的研究方法中,有限元法因其独特的优点,成为研究的主要方法之一。人体下肢有限元模型,作为下肢交通损伤生物力学研究的主要工具,常被用于整车优化、事故重建及损伤研究。下肢有限元模型经历了若干个时期的发展,其计算和仿生精度得到了较大的提升。但是,现有的下肢有限元模型仍存在很多问题：首先,模型均是基于欧美人体建立,与中国人体存在较大差异；其次,现有模型均是将下肢肌肉作为整体建模,不便于模拟真实的肌肉主动力。因此,建立具有肌肉束模型的基于中国人体特征的50百分位男性下肢有限元模型显得至关重要。因此,本文在文献研究基础上,制定了一种用于中国人体下肢有限元模型建模的方案,并用于中国50百分位男性小腿的建模。基于文献研究,获得了中国50th男性下肢的人体统计学数据。利用CT及MRI扫描数据提取了几何数据,进行了网格的划分,模型包含脚骨(26块)、胫骨、腓骨、11束肌肉模型等,并依据中国人体统计学数据,对模型进行缩放,获得50百分位男性小腿网格模型。在此基础上,对模型进行了部件及属性和材料的定义。针对下肢在交通事故中的损伤特点,进行了胫骨与腓骨不同方向的准静态三点弯曲验证,胫骨、腓骨、小腿的侧向不同部位的动态三点弯曲验证,小腿的轴向冲击等验证。结果显示,模型的动力学特性与实验吻合较好,冲击力峰值的大小与出现的时刻基本一致,胫骨骨折弯矩：308.6N·m(Pro)、233.3N·m(Mid)、218.1N·m(Dist),也在耐受限度的范围(254±71N·m)之内,表明所建立的下肢有限元模型具有较好的精度和生物逼真度,所制定的中国人体下肢有限元建模方案具有较高的应用价值。针对下肢长骨刚性冲击器三点弯曲验证时,在骨折之前出现的冲击点位置单元压溃现象,进行了猪腿长骨实验研究,建立了特定样本有限元模型,结合SEM扫描,对压溃的产生过程及影响进行了研究,并探讨了仿真与试验中压溃的不同和如何避免仿真中压溃的影响。通过对压溃现象的实验及仿真研究,表明,压溃导致冲击点的分层现象及骨折路径改变,对实验曲线波动的影响相对于仿真较小,并且冲击区域不使用单元删除算法避免压溃影响是合理的,为模型建立的验证工作提供了参考。最后,在模型建立的基础上,应用模型研究了三种踝关节融合术对临近关节及软组织的影响,对三种踝关节融合术进行了评价。结果显示,前路加压踝关节融合术具有较小的术后临近关节的关节炎病变可能。
[Abstract]:In the research method of vehicle collision safety, finite element method (FEM) has become one of the main research methods because of its unique advantages. As the main tool of lower limb traffic injury biomechanics research, the finite element model of human lower extremity is often used in vehicle optimization. The finite element model of lower extremity has gone through several periods of development, and its calculation and bionic accuracy have been greatly improved. However, there are still many problems in the existing finite element models of lower extremities. Firstly, the models are based on the European and American human bodies, which are different from the Chinese ones. Secondly, the existing models are based on the lower limb muscles as a whole. Therefore, it is very important to establish a 50 percentile male lower extremity finite element model with muscle bundle model based on Chinese human characteristics. Therefore, on the basis of literature study, a finite element modeling scheme for Chinese human lower extremities is developed and applied to the modeling of Chinese 50 percentile male calf. The human body statistics data of the lower extremities of the 50th Chinese male were obtained. The geometric data were extracted from CT and MRI scanning data, and the meshes were divided. The models included 26 pieces of foot bone, tibia, and 11 muscle models of fibula, etc. Based on the Chinese anthropometric data, the model was scaled and the 50 percentile male calf mesh model was obtained. On this basis, the definition of components, properties and materials of the model is given. According to the characteristics of lower extremity injuries in traffic accidents, quasi-static three-point bending of tibia and fibula in different directions is carried out, tibia, fibula, fibula, fibula, fibula, tibia and fibula, The dynamic three-point bending of different lateral position of the leg and the axial impact of the leg were verified. The results showed that the dynamic characteristics of the model were in good agreement with the experiment, and the peak value of the impact force was basically the same as the time when it appeared. The tibial fracture moment: 308.6N 路m ~ (-1) 路m ~ (-1) was 233.3N 路m ~ (-1) N 路m ~ (-1), and it was also within the tolerance limit of 254 卤71 N 路m ~ (-1). It is shown that the established finite element model of lower extremity has good precision and biological fidelity, and the Chinese finite element modeling scheme for lower extremity of human body has higher application value. In this paper, when the rigid impact device of lower extremity is verified by three point bending, the experimental study on the long bone of pig leg is carried out, and the finite element model of specific sample is established, combined with SEM scan. In this paper, the process and influence of crushing are studied, and the difference between simulation and experiment is discussed, and how to avoid the influence of simulation is discussed. Through the experimental and simulation research on the phenomenon of crushing, it is shown that the phenomenon of stratification of impact point and the change of fracture path caused by crushing have less effect on the fluctuation of experimental curve than that of simulation. And it is reasonable to avoid the impact of the impact region without using the unit deletion algorithm, which provides a reference for the verification of the model building. Finally, on the basis of the establishment of the model, the effects of three kinds of ankle fusion on adjacent joints and soft tissue were studied, and the three kinds of ankle fusion were evaluated. Anterior compression ankle arthrodesis has a small possibility of arthritis adjacent to the joint.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R683

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