【作者】 姜圣；

【导师】 卿启湘；

【作者基本信息】 湖南大学 ， 机械工程， 2010， 硕士

【摘要】 汽车平顺性是现代高速、高效率汽车的一个主要性能指标,不仅影响了乘客的乘坐舒适性,而且对保证驾驶员在复杂的行驶和操纵条件下具有良好的心理状态和准确灵敏的反应有重要作用,因此越来越受到人们的重视。但传统的研究分析方法已无法满足当代汽车的需要,虚拟样机作为一项新技术,已广泛地应用于车辆动力学方面,本文正是基于多体动力学软件ADAMS研讨悬架系统对平顺性的影响。本文概述了国内外汽车平顺性研究的发展进程,平顺性评价标准与方法,介绍了多体动力学分析理论与优化设计理论,并提出了本文的研究内容与意义。本文以某款车型为研究对象,提取整车建模所需参数,简化车身、座椅、发动机等部件,利用多体动力学软件—ADAMS,建立了包括钢板弹簧悬架或空气弹簧悬架、轮胎等系统在内的整车平顺性分析动力学模型。基于正弦波叠加原理,利用某公司现场测试路面的数据,分析了实验公路的平整度状况,并编制了适合ADAMS/View的、与实验路面近似的路面文件,且根据位移功率谱密度验证了路面模型的正确性。根据建立好的车——路相互作用模型,实现整车虚拟样机在随机输入激励下,车辆振动模型的时域仿真求解,得到B级路面下,车速为30km/h时,分别配置有钢板弹簧、空气弹簧的车辆在垂直方向的振动情况,根据平顺性评价标准对该车平顺性进行了分析,分析表明,原有板簧设计参数无法达到空气弹簧的平顺性效果,且实验测实验证了模型的正确性。在此基础上,根据板簧设计理论,重新计算了板簧参数,并将钢板弹簧以螺旋弹簧等效替换,根据汽车系统的优化准则,以垂直加速度均方根最小为目标函数,动、静挠度及刚度匹配为约束条件,对弹簧刚度参数进行优化,优化结果表明,平顺性得到有效改善。针对原有车型,通过将钢板弹簧与空气弹簧对比分析,选择钢板弹簧作为更合理的、更具竞争优势的弹性元件。最后根据优化的刚度参数反求钢板弹簧尺寸参数,达到了优化该车平顺性的目的,同时减轻了整车重量,降低了生产成本。更多还原

【Abstract】 Ride comfort is one important index of the high-speed and efficient vehicle, it influents not only the comforance of passengers, but also the psychology. It plays a important role in ensuring a good mentality, accurate and sensitive response of the driver in a complex driving conditions, so people have paid more and more attention on it. But the traditional analysis can’t satisfy the demand, as a new technology, virtual prototyping technology has been widely used in vertical dynamics. This is a discussion of suspension system ride based on the dynamics software ADAMS.Firstly, we summarized the developments of the ride comfort research. Then we dissussed the criteria and methods of ride evaluation and the theory of optimal design.This paper extracted the parameters of some vehicle and analyzes the dynamics model of the vehicle with multi-object dynamics software-ADAMS, including leaf spring suspension or air spring, tires and other systems, it streamlines the body and seat. The paper not only prepared the road file for ADAMS/View based on the superpositon principle and the data of test, but also verified the correctness of the pavement model according to the displacement power spectral density. On the foundation, we conclued the solving time-domain simulation in the random input excitation. The analysis deal with the vibration results of vehicle with the leaf spring or the air spring in the vertical direction when the car was riding on B class road in 30km/h. We evaluated the ride performance according to the standards and compared it with the test result to verify the validity of the model. The result proved that the leaf spring could not fulfill the effect of air spring. We recalculated the spring parameters on the base of the spring design theory and replaced the leaf spring with spiral spring. According to the optimization criteria, we minimized the root mean square of vertical acceleration as the objective function, using dynamic deflection, static deflection and stiffness matching as constraints to optimize the stiffness of leaf spring. It proved that the ride comfort improved effectively. The leaf spring was choosed as the more reasonable and more competitive spring than the air spring. Finally, we reverse to calculate the size of leaf spring according to the optimization. The result optimize the ride comfort, and reduced vehicle weight and the cost of production.更多还原