摘要当今世界每年因汽车交通事故造成了巨大的人员伤亡和社会财概要

摘要：当今世界每年因汽车交通事故造成了巨大的人员伤亡和社会财产损失，汽车安全问题因此成为汽车工业界的研究重点。由于汽车正面碰撞是最常见的交通事故之一，而且正面碰撞事故中造成的死亡人数占首位，因此，汽车正面碰撞抗撞性研究是汽车碰撞安全研究的核心内容。

目前在国外的汽车正面碰撞试验法规中有两种典型的正面碰撞试验评价方法，分别是100%重叠率刚性固定壁障碰撞试验（全宽碰撞）和40%重叠率的偏置变形壁障碰撞试验（40%偏置碰撞）。40%偏置碰撞试验时，车辆前端只有一侧参与碰撞中能量吸收，这种碰撞形态下车身变形大，乘员舱严重的侵入会造成车内乘员的伤害。交通事故统计结果也表明，该事故形态下乘员严重伤害的比例最高，40%偏置变形壁障碰撞试验主要评价安全车身。全宽碰撞和40%偏置碰撞两种碰撞形态乘员的伤害机理不同，对车身和乘员约束系统考核的侧重面也不同，实际碰撞试验研究也表明上述两类试验无法相互替代。我国目前对正面碰撞中全宽碰撞的研究比较多，而对40%偏置碰撞的研究还非常少，要全面提高汽车正面碰撞安全性能，需要同时考虑这两种正面碰撞形态，因此开展40%偏置碰撞的研究工作是十分必要的。

本文应用显式非线性有限元方法，进行基于虚拟试验技术的汽车40%偏置碰撞抗撞性研究。

首先阐述了汽车碰撞计算机仿真分析的基础理论，根据《乘用车正面偏置碰撞的乘员保护》国家标准，建立偏置变形壁障块的有限元模型，并进行了有效性验证；再选择某轿车为研究对象，建立该车针对CMVDR294的100%障碍壁正面碰撞有限元模型，将碰撞仿真结果与试验结果进行对比验证，验证表明了该整车模型的正确性和本文所采用的虚拟试验方法的有效性。

在此基础上，按照欧洲ECE R94.01法规建立该轿车的40%偏置碰撞有限元模型，基于虚拟试验技术对该轿车进行40%偏置碰撞抗撞性分析，确定该轿车40%偏置碰撞抗撞性改进方向和抗撞性改进对策。

最后，按照制定的抗撞性改进对策，对该轿车依次进行了四个方面的改进设计研究，包括：乘员舱的高强度钢加强件改进设计、前纵梁抗撞性改进设计、前纵梁的连接有效性改进设计、碰撞吸能盒与保险杠吸能改进设计。经过改进设计后在一定程度上提高了该轿车的40%偏置碰撞安全性能。

本文的研究结果对于我国汽车企业开展汽车40%偏置碰撞的计算机仿真设计研究具有重要的参考价值。

关键词：虚拟试验，40%偏置碰撞，抗撞性，有限元方法，碰撞安全

Abstract: Every year vehicle traffic accidents lead to a large number of casualties and social property losses around the world, thus vehicle safety problems have been attached great importance by the entire automotive industry. Frontal impact is one of the normal crash types, which cause severe injure and death. Research on frontal crashworthiness of body structure will decrease the injury to passenger, so it’s urgent and necessary to do some research in the field.

In the world frontal impact test statute includes two typical parts: 100% impact (full impact) and 40% offset impact. In the 40% offset impact, only one front side of the vehicle participates the energy absorption of collision, it is a great deformation under this kind of collision shape, the serious invasion of cab can bring the injury to passenger. Traffic Accident statistics also show, that the incident of the serious occupant injuries is the highest in this collision shape, 40% offset deformable barrier impact test major evaluations of the safety body. The full impact and 40% offset impact form two different injury mechanism to occupant, the evaluation focus on the body and occupant restriction system is different, the actual impact test research have shown that these two types of tests can not be substitutes. Now the research on full impact is done in china, but little research on 40% offset impact. It is necessary to comprehensively improve the frontal impact safety performance, taking into account the needs of the frontal impact of these two types, it’s nec essary and meaningful to do research on 40% offset impact.

Research is made on the vehicle 40% offset deformable barrier impact crashworthiness based on virtual test technique using explicit nonlinear finite element method.

At first, the fundamental theories in study of computer simulation are described. According to the state standards《The Frontal Offset Collisions of Vehicle Occupant Protection》, establish the finite element model of offset deformation barriers and have a validation. And choose a saloon car for the research object; establish the finite element model of 100% frontal impact according to CMVDR294. Compare the results of simulation and experiment, the compare certification shows that the vehicle model is correct and the virtual test method is effectiveness in this paper.

On this basis, accordance to European regulations ECE R94.01, establish the finite element model of 40% offset impact, based on virtual test method have 40% offset