交通撞击过程中行人颅脑损伤有限元模型关键参数研究

发布时间：2018-03-21 23:37

本文选题：汽车碰撞　切入点：头部损伤　出处：《南京林业大学》2016年硕士论文　论文类型：学位论文

【摘要】：汽车的发明为人类的生活带来了巨大的方便,但是随着社会的发展,它在给人们带来便捷的同时,也带来了许多安全问题。近年来,交通事故中行人的损伤越来越受到医疗等各科研机构的关注,事故发生时行人作为易受伤群体极易受到伤害。汽车—行人碰撞事故中,行人头部损伤占身体各部位损伤总数的30%以上,是造成交通事故中行人死亡的主要原因。损伤还会导致人体各种能力的丧失以及后遗症,对社会和受害人家庭都将造成巨大的经济损失。开展交通事故中行人颅脑损伤机理的研究具有十分重要的现实意义。本文以50百分位人体头部有限元模型为研究对象,采用有限元法和实验设计技术,分析头部组织材料性能敏感性对颅内因交通撞击而产生的压力响应。针对敏感性较高的颅骨、脑脊液、脑膜和脑组织材料参数进行正交实验设计,获得最佳的参数匹配方案,并对优化前后的模型进行验证对比,具体工作如下:1.有限元模型材料关键参数研究。基于课题组建立的50百分位人体头部有限元模型,研究颅骨和脑组织材料特性,用多因子、多层次的因子实验设计对头部模型主要组成部分材料性能的敏感性进行分析。进一步证实颅骨、脑脊液、脑膜和大脑的材料性能对颅内因撞击而引起的压力有重要的影响。并采用正交实验方法,针对敏感性较高的材料参数进行实验研究,从中获得最佳的参数匹配方案。本研究内容对现有头部碰撞损伤有限元分析提供了新的见解。2.头部碰撞有限元模型有效性验证。头部碰撞损伤力学研究必须建立在完整的有限元模型有效性验证和理论模型修正基础上,该模型具有头部详细解剖学特征和材料属性。通过广泛使用的Nahum和Trosseille实验验证模型的动力学响应及颅内压力,实现理论模型的修正,比较参数改变前后模型生物逼真度。3.典型面部碰撞交通事故案例分析。经过有效性验证过的有限元模型具有较高的生物逼真度,可用于汽车碰撞头部损伤生物力学机理研究。总结典型交通事故面部碰撞类型,仿真模拟常见碰撞情景的颌面部损伤,分析头部颅内压、Von Mises应力、剪应力和应变等生物力学参数,对比脑组织耐受阈值,分析得出,面部碰撞的位置和方向是导致面部骨折位置和严重性的关键因素,而面部外伤中的骨折在一定程度上都与脑损伤(TBI)有关,所以同样也是TBI的关键影响因素。
[Abstract]:The invention of automobile has brought great convenience to human life, but with the development of society, it has brought people convenience as well as many safety problems. In recent years, The injuries of pedestrians in traffic accidents are paid more and more attention by various scientific research institutions such as medical treatment. Pedestrians are vulnerable to injury when accidents occur. Pedestrian head injuries account for more than 30% of the total number of injuries in various parts of the body, which is the main cause of death in traffic accidents. The research on the mechanism of pedestrian craniocerebral injury in traffic accidents is of great practical significance. In this paper, the 50 percentile finite element model of human head is taken as the research object. Finite element method (FEM) and experimental design technique were used to analyze the pressure response of head tissue material sensitivity to intracranial pressure caused by traffic impact. The parameters of meninges and brain tissue were designed by orthogonal experiment to obtain the best matching scheme, and the models before and after optimization were verified and compared. The specific work is as follows: 1. Research on the key parameters of finite element model material. Based on the 50 percentile human head finite element model established by the research group, the material properties of skull and brain tissue were studied. The multilevel factor experimental design was used to analyze the sensitivity of the material properties of the main components of the head model. The material properties of the meninges and the brain have an important influence on the pressure caused by the intracranial impact. The orthogonal experiment was used to study the sensitive material parameters. The best parameter matching scheme is obtained. This study provides a new opinion for the existing finite element analysis of head impact damage. 2. The validity of the head collision finite element model is verified. The mechanical research of head collision damage must be established. Based on the verification of the validity of the finite element model and the modification of the theoretical model, The model has detailed anatomical characteristics and material properties of the head. The dynamic response and intracranial pressure of the model are verified by the widely used Nahum and Trosseille experiments to correct the theoretical model. Comparing the biological fidelity of the model before and after the change of parameters. 3. Case study of typical face collision traffic accident. The finite element model verified by its validity has high biological fidelity. It can be used to study the biomechanical mechanism of head injury in automobile collision, summarize the type of facial collision in typical traffic accident, simulate the maxillofacial injury in common collision scenarios, and analyze the intracranial pressure of head and the Von Mises stress. According to the biomechanical parameters such as shear stress and strain, and comparing the threshold of brain tissue tolerance, it is concluded that the position and direction of facial collision are the key factors leading to the location and severity of facial fracture. Fracture in facial trauma is related to brain injury to some extent, so it is also a key factor of TBI.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U467.14

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