副驾驶离位儿童损伤机理研究

发布时间：2018-04-07 16:13

本文选题：副驾驶安全气囊　切入点：离位儿童　出处：《江苏大学》2017年硕士论文

【摘要】：汽车被动安全产品主要包括方向盘、转向管柱、安全带、安全气囊等,交通事故中,它们能够有效的保护乘员的生命安全,避免乘员与车辆内部发生二次碰撞。目前的车辆安全产品许多并未考虑儿童乘车的情况,儿童在这些产品起作用时不能受到很好的保护,有时候还会受到一些损伤,比如副驾驶安全气囊能够很好的保护50百分位的成年男子,却对于副驾驶位置的儿童造成很大损伤。本文针对副驾驶离位工况的儿童频繁遭受副驾驶气囊展开造成损伤的情况,研究美国联邦机动车安全法规FMVSS208法案的相关内容,明确了副驾驶离位儿童损伤指标的相关内容和气囊低风险展开的试验方法。进一步了解了交通事故中儿童的损伤生物学理论和头部、胸部、颈部的损伤机理,为后续研究做了理论准备。本文的主要研究方法是仿真分析,先用MADYMO软件建立安全气囊的模型,完成气囊的算法选择和折叠建模,在此基础上用气囊的静态展开试验和线性冲击试验加以验证,后加上座椅和假人等建立整个副驾驶离位工况的仿真模型,并用试验加以验证。针对饰盖门形铰链在气囊展开过程中断裂的情况,分析饰盖的应力应变分布,确定相关优化参数和优化水平,对门形铰链结构进行正交优化以减小其最大应变,用SPSS数据分析软件对于正交试验结果进行方差分析,研究各参数对于应变的影响。最终门形铰链在气囊展开过程中不再断裂飞出。研究表明,铰链根部的厚度是对铰链受到最大应变影响较大的参数。选取排气孔直径,气囊织布渗透率、双级气体发生器参数、气囊展开角度、离位位置等参数,分别改变单一因素的值,研究其对副驾驶离位儿童损伤的影响,研究发现:一定范围内,排气孔直径越大,则儿童受到的损伤越小;气囊的织布渗透率越大,则儿童受到的损伤越小。气囊的展开角度较大时,儿童的颈部易受损伤,展开角度较小时,儿童头部易受损伤。双级气体发生器的点火时间间隔较长时,对儿童的保护效果较好。离位位置不同时,儿童远离气囊模块,其损伤会减小。对副驾驶离位儿童的损伤机理进行研究,用SPSS软件对气体物理量和损伤指标进行相关性分析,发现气体压力是导致损伤的主要参数。同时,对所有模型的计算结果进行回归分析,发现HIC15积分时间段内,连续3ms头部加速度的最大值与气体压力线性相关;连续3ms胸部加速度的值与气体压力线性相关;颈部轴向拉伸力的最大值与头胸Z轴方向相对位移最大值线性相关。
[Abstract]:Passive safety products mainly include steering wheel, steering string, seat belt, airbag and so on. In traffic accidents, they can effectively protect the safety of the occupants and avoid the second collision between the occupants and the vehicles.Many of the current vehicle safety products do not take into account the situation of children travelling by car. Children are not well protected and sometimes suffer from injuries when these products work.The co-pilot airbag, for example, protects adult men at the 50 th percentile, but can cause serious damage to children in the co-pilot position.In this paper, according to the condition that children in off-duty condition of co-pilot are frequently injured by co-pilot airbag, we study the relevant contents of the Federal Motor vehicle Safety regulations (FMVSS208) Act in the United States.The related contents of the injury index and the test method of low risk of air bag were defined.The theory of injury biology and the injury mechanism of head, chest and neck of children in traffic accident were further understood, and the theoretical preparation for the follow-up study was made.The main research method of this paper is simulation analysis. First, the model of airbag is established by MADYMO software, and the algorithm selection and folding modeling of airbag are completed. On this basis, the static expansion test and linear impact test of airbag are used to verify the model.The simulation model of the whole off-position condition of the co-pilot is established by adding the seat and dummy, and the simulation model is verified by the experiment.In view of the fracture of the door hinge during the expansion of the air bag, the stress and strain distribution of the cover is analyzed, and the optimization parameters and the optimization level are determined, and the orthogonal optimization of the door hinge structure is carried out to reduce the maximum strain.SPSS data analysis software was used to analyze the variance of the orthogonal test results, and the effect of the parameters on the strain was studied.Finally, the door hinge does not break out during the expansion of the airbag.The results show that the thickness of the hinge root is a parameter which is greatly affected by the maximum strain of the hinge.The parameters, such as the diameter of exhaust hole, the permeability of air bag fabric, the parameters of two-stage gas generator, the angle of air bag development and the position of air bag, were selected to change the value of single factor, respectively, and to study the effects of the parameters on the injuries of children who left the position of co-pilot.It is found that in a certain range, the larger the diameter of the exhaust hole, the smaller the damage to the children, and the greater the permeability of the air bag, the smaller the damage to the children.When the angle of air bag is bigger, the neck of the child is easy to be damaged, and the head of the child is easy to be injured when the angle of expansion is small.When the ignition time of two-stage gas generator is longer, the protective effect of two-stage gas generator is better for children.If the child stays away from the airbag module, the damage will be reduced.In this paper, the injury mechanism of the children who were separated by co-pilot was studied, and the correlation between the physical quantity of gas and the damage index was analyzed by SPSS software. It was found that the gas pressure was the main parameter that caused the damage.At the same time, regression analysis of the results of all the models shows that the maximum acceleration of the head of continuous 3ms is linearly related to the gas pressure in the HIC15 integral period, and the value of the chest acceleration of the continuous 3ms is linearly related to the gas pressure.The maximum axial tensile force of the neck is linearly correlated with the maximum displacement of the Z axis of the head and chest.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U491.61

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