汽车侧围结构抗柱撞设计理论与方法研究

发布时间：2018-05-06 17:27

本文选题：汽车侧面柱碰撞 + 耐撞性优化　；参考：《湖南大学》2016年硕士论文

【摘要】：随着我国汽车工业的快速发展,汽车年产销量稳居世界第一位,与此同时,道路交通安全形势也愈发严峻。相关数据统计显示,汽车侧面碰撞事故是仅次于正面碰撞事故的碰撞形式,这其中包括汽车因失控与路旁的柱状物发生的侧面碰撞事故。由于汽车侧面柱碰撞中柱状物坚硬、碰撞速度高、碰撞接触面积小、碰撞区域车身结构刚度薄弱等原因,乘员会面临极大的损伤死亡风险。因此,该碰撞形式对车身侧围结构的抗柱撞设计提出了非常高的要求。针对上述问题,本文首先对侧面柱碰撞中车体的运动过程和受力情况进行理论分析,得出该碰撞形式下的能量转化过程和假人损伤机理,为后续的车身侧围抗柱撞结构设计提供理论基础。首先建立整车侧面柱碰撞有限元仿真模型,在经过模型有效性验证的前提下,对整车侧面柱碰撞仿真结果中的车身压溃变形、各部件吸能情况、车体加速度响应、碰撞力传递路径以及侧围结构侵入等耐撞性指标进行研究,得出车体抗侧面柱撞耐撞性改进设计的方向和原则,并且对门槛梁、B柱、顶盖横梁、座椅横梁等关键受力吸能部件提出改进方案,有效提高了车身侧面柱碰撞耐撞性。在此基础上,提出一种结合结构拓扑优化和多目标参数优化的车身抗柱撞耐撞性设计方法,并将其应用于车门的抗柱撞优化设计。通过力学计算将车门柱碰撞和车门刚度试验中的动力学问题转化为静力学问题,采用静力学结构拓扑优化方法得到车门防撞梁的最佳材料分布,选取合适的截面得到两种新型的防撞梁结构,通过多目标参数优化使防撞梁同时具备最佳的抗柱撞性能、最轻的质量和最大的结构刚度。提出一种基于正交试验敏感度分析方法的材料匹配设计方法,并将其应用于车身侧围关键部件的材料匹配,通过分析结构总吸能和材料成本对各部件材料替换的敏感度,选择合适的部件进行高强度钢材料的替换,解决了车身不同等级材料的配置问题。论文研究结果表明:从车身结构和材料出发,采用合适的结构优化设计方法和材料匹配方法进行改进设计可以有效提高汽车抗侧面柱撞性能。本文提出的考虑汽车侧面柱碰撞形式的车身结构改进设计方案能够有效提高车身侧面刚度,减少车身受柱撞时的变形量和刚性柱的侵入量,研究方法和结果对同类车型的抗侧面柱撞设计具有参考意义。
[Abstract]:With the rapid development of automobile industry in our country, the annual production and sales of automobile are ranked first in the world. At the same time, the situation of road traffic safety is becoming more and more serious. The related data show that the side impact accident is the second only front impact accident which includes the side impact accident caused by vehicle losing control and the columnar object along the road. Because of the rigid column, high impact velocity, small contact area and weak stiffness of the body structure in the impact area, the occupants will face a great risk of injury and death. Therefore, the impact form has put forward very high requirements for the design of column collision resistance of the body side-girth structure. In order to solve the above problems, the motion process and force of the car body in the side column collision are analyzed theoretically in this paper, and the energy conversion process and the damage mechanism of dummy under the impact form are obtained. It provides a theoretical basis for the subsequent design of the body side-circumference anti-column collision structure. Firstly, the finite element simulation model of the side column collision of the whole vehicle is established. On the premise of verifying the validity of the model, the crash deformation of the body, the energy absorption of each component, and the acceleration response of the vehicle body in the simulation result of the side column collision of the whole vehicle are analyzed. The crashworthiness indexes such as impact force transfer path and lateral structure invasion are studied, and the direction and principle of improving the crashworthiness design of the side column are obtained, and the B column and the top cover crossbeam of the threshold beam, the roof beam, and so on, are obtained. An improved method is put forward to improve the impact resistance of the side column of the car body. On the basis of this, a design method of collision resistance of body column is proposed, which combines structural topology optimization with multi-objective parameter optimization, and it is applied to the optimization design of the car door. By means of mechanical calculation, the dynamic problems in vehicle door post collision and door stiffness test are transformed into static problems, and the optimum material distribution of the door anti-collision beam is obtained by using the static structure topology optimization method. Two new types of anti-collision beam structures are obtained by selecting appropriate cross-sections. The anti-collision beams have the best anti-column impact performance, the lightest mass and the maximum structural stiffness through multi-objective parameter optimization. A material matching design method based on the sensitivity analysis method of orthogonal test is proposed, and it is applied to the material matching of the key parts around the body. By analyzing the sensitivity of the total energy absorption of the structure and the material cost to the material replacement of each component, the material matching design method is proposed. Choosing suitable parts to replace the high strength steel material solves the problem of configuration of different grades of body materials. The research results show that: from the view of the body structure and materials, the improved design using the appropriate structural optimization design method and material matching method can effectively improve the vehicle anti-side column impact performance. In this paper, the improved design scheme of car body structure considering the form of side column collision can effectively improve the stiffness of the body side, reduce the deformation of the body when it is hit by the column and the intrusion of the rigid column. The research methods and results are of reference significance for the design of the side column collision resistance of the same type of vehicle.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.83

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