25%正面小偏置碰撞下某车型车身结构和约束系统仿真研究

发布时间：2018-03-01 19:19

本文关键词： 小偏置碰撞入侵量结构耐撞性约束系统　出处：《重庆理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：在许多正碰事故中,如车辆左前角与另一车辆右前角相碰撞、斜向碰撞或与窄物体碰撞(如树、电线杆)等,由于仅有小部分车身参与碰撞,即使正确佩戴安全带和应用安全气囊,仍会导致乘员的死亡,这类交通事故被称为低重合率正面碰撞(SOFC)。在这类交通事故中,车体避开了多数车型的保险杠和前纵梁等结构件,碰撞能量直接传递至轮胎、乘员舱,导致轮胎总成失效或者相当容易地入侵乘员舱,对驾驶员造成直接的伤害。因此,研究低重合率正面碰撞很有必要。本文以某小轿车为研究对象,提出了一整套完整的低重合率正面碰撞(SOFC)下的车身结构优化流程,并对应地进行了针对该车型的约束系统匹配。首先介绍了美国公路安全保险协会(IIHS)提出的关于低重合率正面碰撞(SOFC)的评价试验(25%正面小偏置碰撞试验)及评价规范,采用hypermesh软件建立该车型的25%小偏置碰撞(SOI)工况,经过LS-DYNA软件分析计算后,将仿真数据与实验数据进行对标,验证模型的可信度。然后分析基础模型的结构耐撞性,以IIHS提出的评价指标对基础模型进行结构耐撞性评价。由此得出基础模型在小偏置碰撞下结构耐撞性存在的问题,然后对主要结构件设置测力截面,进行截面力分析,研究问题出现的原因和实质,得出具体的结构优化方案,应用该方案进行结构优化,对比基础模型和优化模型的结构耐撞性差异,然后分析优化模型主要结构件的截面力,分析优化方案的实质。最后对主要结构件进行刚度匹配,得出最终优化模型,将最终优化模型与之前的优化模型进行结构耐撞性对比,验证刚度匹配方案的可行性。在进行结构优化后,本文针对最终优化模型建立小偏置碰撞下的乘员—约束系统模型,采用正交实验法进行约束系统匹配,然后分析假人运动状态,最后对最终优化模型的车身结构耐撞性、假人伤害值和约束系统/假人运动学进行总体评价,验证本文思路的正确性。
[Abstract]:In many positive impact accidents, such as the left front corner of the vehicle colliding with the right front corner of another vehicle, the oblique collision or the collision with a narrow object (such as trees, utility poles), etc., as only a small part of the body is involved in the collision, Even the proper wearing of seat belts and the application of airbags can still lead to the death of the occupants, known as low-coincidence frontal collisions. In such accidents, the body avoids the bumper and front girder structures of most models. The impact energy is transmitted directly to the tyre, the passenger compartment, causing the tire assembly to fail or invading the crew compartment quite easily, causing direct damage to the driver. It is necessary to study the low coincidence rate frontal impact. In this paper, a complete set of body structure optimization process under the low coincidence rate frontal collision (SOFC) is proposed. The constraint system matching for the vehicle is carried out correspondingly. Firstly, the evaluation test on low coincidence rate frontal collision (SOFC) proposed by the American Highway Safety Insurance Association (IIHSS) and its evaluation specification are introduced. The 25% small offset collision mode of the vehicle is established by using hypermesh software. After the analysis and calculation of the LS-DYNA software, the simulation data and the experimental data are calibrated to verify the credibility of the model, and then the structural crashworthiness of the basic model is analyzed. The structural crashworthiness of the foundation model is evaluated by the evaluation index proposed by IIHS. The problems of the crashworthiness of the foundation model under small bias impact are obtained, and then the force section of the main structural parts is set up, and the cross-section force analysis is carried out. After studying the cause and essence of the problem, the concrete structural optimization scheme is obtained, and the structural optimization scheme is used to optimize the structure. The difference of structural crashworthiness between the basic model and the optimization model is compared, and then the cross-section force of the main structural parts of the optimization model is analyzed. The essence of the optimization scheme is analyzed. Finally, the stiffness matching of the main structural parts is carried out, and the final optimization model is obtained. The final optimization model is compared with the previous optimization model for structural crashworthiness. The feasibility of stiffness matching scheme is verified. After structural optimization, this paper establishes the occupant-constrained system model for the final optimization model under small bias collision, and uses orthogonal experiment method to match the constrained system. Then the motion state of the dummy is analyzed and the impact resistance of the body structure the injury value of the dummy and the kinematics of the restraint system / dummy are evaluated to verify the correctness of the idea in this paper.
【学位授予单位】：重庆理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U467.14

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