汽车乘员腰椎的随机振动响应特性分析

发布时间：2018-05-09 20:14

本文选题：人机工程学 + 有限元分析　；参考：《东北大学》2013年硕士论文

【摘要】：近年来随着汽车越来越大众化,车辆舒适性和乘员的健康问题逐渐引起了人们的重视。由于发动机振动和路面不平度等因素,汽车乘员会暴露在振动环境中。研究表明驾驶员中有要痛症状的占60%左右,要明显高于非驾驶人员。为了研究汽车振动环境和人体腰椎病症之间的关系,有必要提取人体腰椎部分进行生物力学分析。本文通过建立人体T12-Pelvis三维有限元模型结合生物力学的知识,对处在车辆振动环境中人体腰椎进行静动态特性分析,以此来获得人体脊椎在静力学和振动环境下的损伤机理。首先,通过CT扫描、Mimics、Ansys等软件建立完整的T12-Pelvis三位有限元模型,对该模型每一节段和整体分别进行静力加载,将结果同国内外文献对比,验证了模型的有效性。其次,运用Workbench静力学分析模块模拟T12-Pelvis有限元模型中T12-L1节段和整体模型在直立、前俯、单向侧弯、轴向扭转四种坐姿下的静力学环境,提取出T12-Pelvis的位移、应力等静力学仿真结果,分析结果得出人体腰椎承受静力载荷的结构和容易受损的部位,总结出人体腰椎承受静力时的损伤机理。再次,利用Workbench中动态分析模块对T12-Pelvis有限元模型整体进行模态分析,分析模型的固有频率和振型可知第三阶模态对人体影响最大。改变人体上半身重心的坐标后的模态分析,结果表明重心的改变会导致固有频率提高,重心后移会减小共振位移,前移会增大共振位移。最后,在模态分析的基础上,以路面不平度功率谱作为输入激励,对乘员T12-Pelvis有限元模型整体进行随机振动分析,得到在路面随机振动下的敏感频率范围为8-9Hz,并通过位移和应力的响应分析T12-Pelvis模型的动态特性,研究结果为车辆环境下人体脊椎的保护提供参考。
[Abstract]:In recent years, with the increasing popularity of automobiles, vehicle comfort and occupants' health problems have gradually attracted people's attention. Car occupants will be exposed to vibration due to engine vibration and road roughness. The study showed that 60% of drivers had symptoms of pain, which was significantly higher than that of non-drivers. In order to study the relationship between vehicle vibration environment and lumbar disease, it is necessary to extract the part of human lumbar spine for biomechanical analysis. In this paper, the three-dimensional finite element model of human body T12-Pelvis combined with the knowledge of biomechanics is established to analyze the static and dynamic characteristics of lumbar vertebrae in vehicle vibration environment, so as to obtain the damage mechanism of human spine under static and vibration conditions. Firstly, a complete T12-Pelvis three-bit finite element model is established by means of CT scanning software such as Mimics / Ansys. The static loading of each segment and whole of the model is carried out, and the results are compared with the domestic and foreign literatures, and the validity of the model is verified. Secondly, Workbench statics analysis module is used to simulate the static environment of T12-L1 segment and integral model in T12-Pelvis finite element model under four sitting positions: vertical, forward bent, unidirectional lateral bending and axial torsion, and the displacement and stress of T12-Pelvis are extracted from the static simulation results. The results show that the structure of human lumbar vertebrae is subjected to static load and the easily damaged part, and the mechanism of human lumbar vertebrae being subjected to static load is summarized. Thirdly, the modal analysis of T12-Pelvis finite element model is carried out by using the dynamic analysis module in Workbench. The analysis of the natural frequency and mode shape of the model shows that the third mode has the greatest influence on the human body. The modal analysis results show that the change of the center of gravity will lead to the increase of the natural frequency, the backward shift of the center of gravity will decrease the resonant displacement, and the forward shift will increase the resonant displacement. Finally, on the basis of modal analysis, the random vibration analysis of the T12-Pelvis finite element model is carried out by taking the road roughness power spectrum as the input excitation. The sensitive frequency ranges from 8 to 9 Hz under random vibration of road surface. The dynamic characteristics of T12-Pelvis model are analyzed by the response of displacement and stress. The results provide a reference for the protection of human spine in vehicle environment.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R642;R318.01

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