商用车悬架系统隔振特性分析研究

发布时间：2018-05-07 02:29

本文选题：商用车悬架 + 平衡悬架　；参考：《吉林大学》2017年硕士论文

【摘要】：商用车正不断朝着重型化、专业化趋势发展,针对直接影响运输效率的行驶平顺性研究,多集中在改善驾驶室座椅与悬置隔振上。随着移动互联网和物流行业的飞速崛起,商用车运输的对象扩展至高价值、易损坏物品,车厢中货物的安全性、完整性越来越被重视,转换到工程上就是簧载质量振动问题,因此本文以装有钢板弹簧的多轴商用车悬架系统为研究对象,围绕其隔振性能展开研究。商用车悬架系统由单前桥悬架和中后桥平衡悬架组成,涉及多根车轴耦合,对其振动性能的研究主要采用建模仿真方法,本文建立了精确的动力学模型:首先采用Timoshenko离散梁建模方法,在ADAMS/Chassis Leaf Spring模块下建立前、后钢板弹簧模型后,重新定义了簧片间接触和摩擦,并在钢板弹簧试验机上进行了力学特性试验,验证了平衡悬架钢板弹簧的静刚度特性及不同频率、幅值激励下表现的动刚度特性,仿真与试验结果间足够小的误差表明模型复杂度降低的同时达到了精度要求。然后按照悬架系统拓扑结构,基于ADAMS/View建立了车架,前后悬架(包括车桥)子系统及它们之间的连接,轮胎,激励试验台模型;还研究了不平路面理论,建立了扫频、随机、脉冲路面激励输入模型,最终构建了完整的悬架系统动力学仿真模型。目前单独研究商用车悬架隔振特性即簧载质量振动响应的评价体系及标准并不完善,本文基于ISO 2631-1:1997(E)和GB/T 4970-2009标准,以时域内簧载质量质心处垂向、纵向、侧向加速度作为振动输出量,及对输出量进行傅里叶变换得到频域内自功率谱密度,并结合最大(绝对值)加速度响应、加速度均方根值,共同用于分析路面激励振动通过悬架向车身传递的表现。由ADAMS模型初步计算得到分析指标,与Truck Sim整车动力学模型输出进行对比,结果验证了ADAMS悬架模型的准确性。然后分别在满载和空载工况下,先进行模态分析,再依次施加扫频及考虑不同车速的随机、脉冲路面激励,对悬架系统动力学模型进行振动响应分析运算,得到簧载质量分别在满载工况下3Hz附近和空载工况下7Hz附近出现的垂向振动峰值不符合实用固有频率范围的结论,需要对模型结构进一步改进以减弱异常振动。悬架刚度决定垂向振动特性,通过对比前、后悬架刚度,论证了影响隔振特性的主要因素是平衡悬架部分。然后分析了橡胶衬套刚度参数、钢板弹簧两端支撑结构形式在满载、空载工况下对悬架系统隔振特性的影响程度,分析结果表明钢板弹簧两端合适的弹性支撑能够很好地改善垂向振动的表现,为商用车悬架开发提供了理论依据。
[Abstract]:Commercial vehicles are becoming more and more heavy and specialized. The research on ride comfort which directly affects transportation efficiency is mainly focused on improving cab seat and mounting isolation. With the rapid rise of mobile Internet and logistics industry, the object of commercial vehicle transportation is expanded to high value, easily damaged, and the safety and integrity of the goods in the carriage are paid more and more attention to. Therefore, the vibration isolation performance of multi-axle commercial vehicle suspension system with leaf spring is studied in this paper. The commercial vehicle suspension system consists of a single front axle suspension and a middle rear axle balanced suspension, which involves multiple axle coupling. The vibration performance of commercial vehicle is mainly studied by modeling and simulation method. In this paper, a precise dynamic model is established. Firstly, the contact and friction between the Reed and the spring are redefined by using the Timoshenko discrete beam modeling method and the model of the leaf spring before and after the establishment of the ADAMS/Chassis Leaf Spring module. The static stiffness characteristics of the balanced suspension leaf spring and the dynamic stiffness characteristics under different frequency and amplitude excitation are verified by the mechanical characteristic test on the leaf spring testing machine. The small error between the simulation and the experimental results shows that the complexity of the model is reduced and the precision requirement is achieved. Then according to the topological structure of suspension system, based on ADAMS/View, the model of frame, front and rear suspension (including vehicle bridge) subsystem and the connection between them, tire and excitation test bed are established, and the theory of uneven road surface is also studied, and the frequency sweep, random, and random are established. Finally, a complete dynamic simulation model of suspension system is constructed by impulse road excitation input model. At present, it is not perfect to study the vibration isolation characteristic of commercial vehicle suspension, that is, the evaluation system and standard of spring mass vibration response. This paper is based on ISO 2631-1: 1997 (E) and GB/T 4970-2009 standard, using vertical and longitudinal spring mass center in time domain. The lateral acceleration is used as the vibration output, and the Fourier transform of the output is used to obtain the self-power spectral density in the frequency domain. Combined with the maximum (absolute) acceleration response, the root mean square (RMS) of the acceleration is obtained. It is used together to analyze the transmission of exciting vibration from road surface to body through suspension. The analysis index is obtained from the ADAMS model and compared with the output of the Truck Sim vehicle dynamics model. The results verify the accuracy of the ADAMS suspension model. Then under full load and no load conditions, modal analysis is carried out first, then sweep frequency and random impulse road excitation considering different speed are applied in turn to analyze the vibration response of the dynamic model of suspension system. It is concluded that the peak value of vertical vibration of spring mass near 3Hz under full load condition and near 7Hz under no-load condition does not accord with the practical natural frequency range. The model structure needs to be further improved to reduce abnormal vibration. The suspension stiffness determines the vertical vibration characteristics. By comparing the pre-and post-suspension stiffness, it is proved that the main factor that affects the vibration isolation characteristics is the balanced suspension part. Then, the stiffness parameters of rubber bushing, the influence of the structure form of leaf spring at full load and no-load on the vibration isolation characteristics of suspension system are analyzed. The results show that the suitable elastic support at both ends of the leaf spring can improve the vertical vibration performance and provide a theoretical basis for the development of commercial vehicle suspension.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U463.33

【相似文献】