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通过台车试验,对受方向盘角度影响和座椅刚度等影响下的几种典型的胸部伤害情况进行了分析研究,指出了在无安全气囊或气囊作用偏弱的情况下,方向盘的水平角度一般时容易造成胸部加速度偏大,方向盘水平角度偏大时容易造成胸部压缩变形量偏大;另外,也指出了碰撞中,坐垫的深度偏大和前端刚度偏强时容易增大假人胸部伤害,坐垫前端刚度偏弱时导致假人下沉可造成胸部伤害指标提高,这为约束系统的匹配提供了参考。 相似文献
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本文利用MADYMO软件建立包含P系列儿童假人、一款国产汽车用儿童座椅和试验台车的儿童乘员约束系统的计算机仿真模型,并模拟了ECE-R44法规规定的正面碰撞台车试验环境。通过与对应产品的台车碰撞试验结果对比,对该模型有效性进行了验证。同时,在已验证模型的基础上,对儿童座椅及台车试验系统设计参数对儿童乘员响应的影响进行了分析,结果表明儿童座椅的摩擦系数、成人安全带刚度、儿童座椅安全带定位孔孔位置对儿童乘员在正面碰撞中的响应影响较大,通过适当的儿童约束系统设计可以降低儿童乘员在碰撞事故中的受伤几率。 相似文献
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在前方道路突然出现障碍物的危急情况中,车辆采用自动紧急转向来避障,由于情况紧急,车辆在转向过程中仍可能与其他道路参与者发生碰撞事故。当车辆采用自动紧急转向避让道路前方路口突然闯入的车辆时,与对向来车发生斜角碰撞,由此,对该特定场景的转向-碰撞全过程进行一体化仿真,分析乘员在转向阶段因车辆横摆和侧倾运动引起的离位现象以及离位在碰撞过程中对乘员的动态响应和损伤造成的影响。首先,建立由自动紧急转向导致的斜角碰撞场景;其次,在该场景中,确定车辆在最小避障距离内的紧急变道路径,并计算车辆和乘员在变道过程中的动态响应;碰撞事故发生时刻选取为本车在紧急转向过程中易与对向来车发生碰撞的时刻,且在该时刻乘员具有较大潜在损伤风险;然后,在时域上结合车辆转向阶段和碰撞阶段的运动响应,将其作为整体输入,对乘员在全过程的动态响应进行一体化仿真;最后,分析离位对乘员损伤的影响规律以及影响因素。研究结果表明:紧急转向会导致乘员产生明显的横向离位,降低了约束系统对乘员的保护效果,致使乘员头部和颈部在碰撞中的人车相对运动速度和相对位移明显增大;横向离位使得乘员头部偏离安全气囊中央区域,降低了安全气囊的保护作用;这2个因素导致了乘员头部损伤评价指标HHIC36增加7.20倍,颈部损伤评价指标Nij增加2.32倍;乘员头、颈部损伤具有随横向离位程度减小而减小的趋势。 相似文献
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Radu Alexandru Ionut Cofaru Corneliu Tolea Bogdan 《International Journal of Automotive Technology》2017,18(6):1017-1025
The aim of the paper was to determine the kinematic parameters that influence the occupant injury risk through a mathematical model. The developed model is a 2D model composed of 4 bodies (2 vehicles, thorax and head). The head and thorax are interconnected with a rotation joint and a torsion spring meant to stiffen the relative movement between the bodies. The thorax is connected with the vehicle body by a linear spring meant to simulate the seatbelt stiffness. The model was solved using Lagrange principle and the validation of the model was made through a crash test performed using the same initial conditions and comparing the obtained values of the displacement, velocity and acceleration parameters with the ones obtained with the mathematical model. The head and torso were chosen due to the fact that they are the common parts of the body that get injured, especially the head with the change of 80 % to cause fatal injury in car’s frontal collision. Once the model was validated, the stiffness of the seatbelt was modified in order to determine the behavior of the occupant in case of car frontal collisions. When the seatbelt stiffness was reduced, the occupant displacement and velocity increased, while by increasing the stiffness, these parameters decreased. The values of the developed model presented a high degree of similarity with the results obtained from the crash test with an error of 10 %. This model can be used by engineers to easily asses the occupant injury risk in case of vehicle frontal collisions. 相似文献
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针对目前儿童座椅常存在因结构设计不合理而导致的保护效果差的问题,基于MADYMO建立了包含台车座椅、某款典型儿童座椅、五点式安全带、P3 儿童假人的儿童约束系统模型,根据 GB 27887 标准进行正面碰撞台车试验,基于试验结果从假人运动轨迹和损伤指标两方面对模型进行了验证。结果表明,建立的儿童约束系统模型能较真实地反映实车碰撞过程,具有较高的准确性。在模型验证的基础上,针对碰撞中座椅上部存在变形量过大的问题,提出了在椅背顶部后侧加装加强板,并将椅背与椅盆连接处位置原有的凹槽贯通的改进方案,对改进后的儿童座椅进行了不同加速度下正面碰撞工况的仿真分析和安全性评估。结果表明,改进方案能在座椅质量不增加的前提下,有效减少椅背的变形量,确保碰撞中座椅结构的完整性和儿童的安全,达到了预期的防护效果。研究结果可为儿童座椅的设计和改进提供支撑和参考。 相似文献
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采用Pam-Crash仿真软件,在已验证的6岁儿童乘员有限元模型上,施加ECE R129法规中规定的减速度曲线,以模拟汽车在侧面碰撞事故中后排儿童乘员的头部损伤情况。通过头部质心合加速度、头部性能指标(HPC)、脑组织Von Mises应力、颅内压、剪切应力和泡沫与头部之间的接触力等评价指标,研究侧面碰撞时安全座椅侧翼结构中头枕部位填充吸能泡沫对儿童乘员头部的保护效果。结果表明:安全座椅中填充泡沫可有效降低侧面碰撞对头部的损伤,且填充PU泡沫的保护效果要优于EPS泡沫。 相似文献
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在高度自动化车辆(Highly Automated Vehicle,HAV)中,由于不再需要驾驶人,乘客之间可以实现面对面的交流,这给车辆座椅的布置提供了更大的灵活性。为提高HAV的碰撞安全性,提出使用旋转座椅来改变人体朝向与碰撞方向相对位置的规避策略,其基本思路是在碰撞发生前通过主动改变座椅朝向来降低乘员损伤。首先,利用尸体试验数据对所建立的碰撞模型进行验证;然后,基于4种不同的座椅朝向,利用THUMSTM人体模型进行初始速度为56 km·h-1的正面碰撞模拟试验,以确定相对安全的座椅朝向位置;最后,预测座椅旋转过程本身以及旋转至某位置后发生碰撞的乘员损伤风险。在静态正面碰撞中,选择0°、90°、135°和180°四种不同的座椅朝向进行乘员损伤预测和比较,结果表明180°朝向时的乘员损伤风险最小。在此基础上,模拟了200 ms内将座椅旋转±45°和±90°,以及分别在0 ms和100 ms时间延迟后引入碰撞的试验过程。研究结果表明:200 ms能够将乘员旋转±45°和±90°而不引起额外的人体损伤,并且在无时间延迟时,旋转至背对碰撞方向的乘员损伤,比正面碰撞中0°、90°和135°座椅朝向的乘员损伤更低,证明了该损伤风险规避策略的有效性。 相似文献
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P. E. Pfeffer M. Harrer D. N. Johnston 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2008,46(5):413-428
For the on-centre handling behaviour of vehicles the steering system is absolutely important. To investigate the interaction of the vehicle and steering system a validated, especially tailored simulation model was developed. Some meaningful vehicle and steering system parameters are altered to show the influence on steering wheel torque, steering feel and understeer. The results underline the importance of an accurate steering system model. Identified measures to improve the centre feel and steering response were a stiffer torsion bar, a higher cornering stiffness or a lower overall steering ratio. The steering response, however, suffers when the centre feel is improved by a higher trail. The steering rack friction reduces mainly the steering response while the steering column friction decreases the centre feel whereas a stiffer torsion bar lessens the understeer tendency. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):413-428
For the on-centre handling behaviour of vehicles the steering system is absolutely important. To investigate the interaction of the vehicle and steering system a validated, especially tailored simulation model was developed. Some meaningful vehicle and steering system parameters are altered to show the influence on steering wheel torque, steering feel and understeer. The results underline the importance of an accurate steering system model. Identified measures to improve the centre feel and steering response were a stiffer torsion bar, a higher cornering stiffness or a lower overall steering ratio. The steering response, however, suffers when the centre feel is improved by a higher trail. The steering rack friction reduces mainly the steering response while the steering column friction decreases the centre feel whereas a stiffer torsion bar lessens the understeer tendency. 相似文献
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Yasuhiro Matsui Masami Kubota Shoko Oikawa 《International Journal of Automotive Technology》2018,19(1):77-83
The Japan New Car Assessment Program (J-NCAP) evaluates the performance of cars in terms of protection against whiplash injuries in rear-end collisions. In the test protocol, a simplified triangular acceleration is applied to the sled. This study clarifies whether biofidelic rear-impact dummy II (BioRID II) measurements obtained for simplified triangular acceleration reflect car-to-car rear-end impacts in real-world accidents in Japan. We conducted a car-to-car rear-end impact experiment and a simplified-triangular-acceleration sled test. Our results indicate that the time series of dummy responses were approximately consistent in the two test conditions. The neck injury criterion (NIC) and maximum acceleration of the head and T1 measured using the BioRID II dummy were similar in the car-to-car and sled experiments. This revealed that the J-NCAP test protocol using simplified triangular acceleration reflects the car-to-car rear-end impact experiment using Japanese cars, in terms of the NIC and maximum acceleration of the head and T1. 相似文献
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假人主要伤害值对等效双梯形减速度曲线的灵敏度分析 总被引:2,自引:0,他引:2
文中利用同时配置气囊和安全带、只配置安全气囊以及只配置安全带的3种不同正碰台车试验的MADYMO数学仿真模型,分析了等效双梯形曲线不同特征参数对假人头部HIC值、胸部3ms累积加速度以及胸部变形量等3种伤害值的影响. 相似文献
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目前,国内外有关汽车内部凸出物试验的标准中均只将假人头部作为参考指标;而正面碰撞法规和C-NCAP(2021版)中均将假人的头、颈、胸、骨盆、腿等部位损伤值作为衡量汽车安全性能优劣的重要评价指标。本文通过滑台碰撞试验方法,对汽车内部凸出物试验测评方法进行研究;结果显示:假人的头、颈、胸、腿部均受到不同程度的损伤;尤其是95th假人的骨盆位移量过大,造成假人下半身受到损伤更为严重。因此,本文建议乘用车内部凸出物试验测评方法中,应适度考量假人多个部位及其损伤指标,旨在不断完善我国汽车安全标准体系,进一步提升汽车安全性能,更好地保护驾乘人员的乘车安全。 相似文献