【作者】 荆友录；

【导师】 温卫东； 魏民祥；

【作者基本信息】 南京航空航天大学 ， 车辆工程， 2009， 博士

【摘要】 车辆碰撞相容性问题是目前造成不同车辆之间发生碰撞时伤亡率较高的重要原因之一,货车与乘用车正面碰撞相容性的问题尤为严重,如何提高货车与乘用车正面碰撞时的相容性成为汽车被动安全性分析中的一个关键环节。在车对车的碰撞中,良好的相容性要求,汽车不仅能保护自己车内乘员的安全,而且也必须考虑对方车内乘员的安全,使车辆对双方乘员能提供相同的安全保护水平。目前国内对车辆碰撞相容性问题的研究较少,因此开展这方面的研究具有重要的理论意义和工程应用价值。本文主要进行了以下几方面的研究:(1)综述了相容性问题的国内外研究现状,并综述了薄壁构件抗撞性优化的研究现状以及高吸能泡沫材料的研究现状,提出了碰撞相容性研究存在的问题及解决思路。然后基于显式有限元数值求解技术,给出了进行接触-碰撞界面的处理与算法,并给出了优化设计代理模型近似求解理论;(2)对四种不同截面结构薄壁直梁的耐撞性进行了研究,分析了结构参数的变化对结构耐撞性能的影响。以矩形薄壁梁为研究对象,对结构参数变化时薄壁直梁件轴向冲击载荷下的耐撞性进行了优化。探讨了提高矩形截面薄壁梁耐撞性能的改进措施。得到了不同结构参数和改进措施对结构耐撞性能的影响规律;(3)提出了在矩形薄壁梁内部填充成组圆管的组合梁结构,研究了组合梁在冲击载荷作用下的耐撞吸能特性,并分析了内部填充圆管直径(或排列)、壁厚和长度等参数变化对组合结构耐撞性能的影响。得到了填充圆管的数量、壁厚和长度参数变化对碰撞力峰值、碰撞力均值和吸能特性的影响规律;(4)参照欧洲ECE-R93法规,提出了在货车前下部安装前部钻碰防护装置FUP(Front Under-run Protector)来解决钻碰。建立了货车前下部防护装置的有限元模型,研究了静态载荷下FUP的防钻性能和冲击载荷作用下结构的能量吸收与变形特性,分析了FUP结构对货车与乘用车正面碰撞相容性的影响;(5)提出了在矩形薄壁梁内部填充圆管组的组合FUP支架,对内部填充圆管直径(或排列)、圆管壁厚和圆管长度等参数进行合理选择,研究了内部填充圆管的组合FUP在冲击载荷作用下的防钻性能和相容性;(6)研究了泡沫铝填充薄壁金属件的变形与吸能特性,建立了泡沫铝填充FUP支架的有限元数值模型,研究了泡沫铝填充FUP支架后对货车防钻碰性能和相容性的变化。最后采用响应面法对泡沫铝填充FUP的结构进行了优化研究,得到了耐撞性能较好的填充FUP结构。更多还原

【Abstract】 Compatibility in a collision between different type vehicles is one of the important causes that results in big ratio of casualty. Compatibility between a passenger car and a truck is more serious in all impacts between vehicles. It is becoming a key items how to improve the level of compatibility in a frontal collision. We can say that the compatibility of a vehicle is good if it takes into account its partner passengers’safety as well as its own passengers’when two vehicles impact together. Thus the passengers in the different vehicles are safeguarded in the same safety level. Few researches focus on compatibility in a collision between different type vehicles. Therefore, it’s very important to research on this aspect.The main research works include:(1) At the beginning of the dissertation, recent developments of compatibility and crashworthiness of vehicles are briefly summarized. Thin-walled components optimization and researches on high energy-absorption foam materials are also summarized. The matters needed to been solved are found out and some schemes are put forward to solve this problem. Then, the main theoretical backgrounds are introduced, such as explicit finite element technique, contact-impact problems and response surface method;(2) The crashworthinesses of thin-walled straight beams with different shapes are studied based on finite element theory. Structural crashworthinesses are analyzed when the structural parameters are different. Thin-walled straight beam with rectangular section are studied based on dynamic finite element model. Crashworthiness optimization of thin-walled beam, which is subjected to axial impacting load, is processed. Many measures are researched to improve the crashworthinesses of thin-walled beams with rectangular section. The characteristics of various structures and measures effection on crashworthiness are derived;(3) The combined rectangular section thin-walled beams filled with circular section tubes are brought forward. Energy-absorbing characteristics and crassworthiness of the combined beams are studied while they are subjected to axial impacting loads. Influences of parameters change including diameter (or arrangement), wall thickness and length of filled tubes are analyzed on performance of combined beams. The parameters influences on crashworthiness are derived when they are different;(4) According to ECE regulation ECE-R93, front under-run protector (FUP) is put forward and installed on the truck in order to settle the issue of under-run. The finite element model of truck’s FUP is set up. The performance of FUP used to prevent from under-run is studied while it bears static load. Energy-absorbed performance and deformation characteristics of FUP are studied while it bears impacting loading. The influence of FUP assembly on compatibility is analyzed while a truck impacts passenger vehicle in a frontal collision;(5) FUP bracket which combining rectangular section thin-walled beams with circular section tubes is advanced. The parameters (including diameter, wall thickness and length of filled tubes) are selected correctly. The performances of combined FUP used to prevent from under-run and improve compatibility are studied;(6) Deformation and energy-absorbing characteristics of thin-walled component filled with foam aluminium are studied. The finite model of FUP filled with foam aluminium is set up. The influence of FUP filled with foam aluminium is studied on compatibility and characteristic of proteting from under-run. Finally, the structure of FUP bracket filled with foam aluminium is optimized by response surface method. Optimal structure of FUP bracket filled with foam aluminium is derived.更多还原