【作者】 李凌阳；

【导师】 陈立平； 张云清；

【作者基本信息】 华中科技大学 ， 机械设计及理论， 2013， 博士

【摘要】 本文针对悬架技术的几个关键问题，进行了系统化的深入分析和研究，提出了新的思路、方法和模型，并将理论计算、仿真分析与实物试验相结合，以试验结果数据为依据，验证了新方法的有效性以及新模型精度。本文主要研究内容包括以下几个方面：(1)对考虑非线性的两自由度悬架模型进行了推导，给出了偏频和阻尼比的理论算法，针对已有阻尼比计算方法的缺陷，引入新的阻尼比计算方法，改进阻尼比辨识的方法，消除对数衰减法出现假峰的情况，利用面积法计算阻尼比，提高了阻尼比的辨识精度。(2)对具有独立悬架系统的汽车而言，簧上质量无法用简单的质量叠加方法来计算。为此提出一种简化模型，避开轮胎非线性特性，利用试验得到的轮心及车身部分的加速度结果来辨识簧上、簧下质量，提高了质量参数估算的精准性，对悬架设计分析研究具有重要的意义。(3)建立了新的橡胶衬套非线性光滑迟滞模型，结合试验数据，确定模型参数初始值，对衬套回复力进行求解；通过对模型参数进行灵敏度分析，忽略参数交互作用，确定主要参数对模型输出的影响，为有可能的模型修改提供参考依据。结合静刚度和动刚度测试试验结果，分析试验数据，提出考虑预载作用的修正模型，扩展了橡胶衬套非线性光滑迟滞模型的应用范围；采用遗传算法进行参数辨识，获取修正模型的精确参数，并将仿真结果与试验数据相对比，验证模型的正确性和精度。(4)采用了一种新的试验方法，使用相对来说比较简单便宜的传感器，通过对加速度、位移、应变等比较容易获取的物理量进行测试，逆向求解轮心六分力。并在逆向求解得到轮心六分力后，还根据悬架多体系统动力学模型正向得到各连接点的受力，将仿真值与测量值进行对比，以验证逆向求解过程及结果的正确性。并在此基础上计算得到零部件的疲劳寿命，然后以悬架关键衬套刚度为设计变量进行优化分析，提高了悬架零部件的疲劳寿命。本文以汽车悬架为研究对象，结合目前悬架研发过程中的实际情况，丰富了悬架研发的模型体系，该模型体系能够使悬架的研发流程更加具有合理性，使其研发过程更加规范化，从而提高悬架的研发品质与研发效率。本文所采用的创新方法对悬架研发过程具有极大的现实意义和促进作用。更多还原

【Abstract】 Aiming to several key problems of suspension, the systematic analysis and researchare carried out. A new analysis method and model is proposed in this thesis, whichcombines the theory calculation and simulation analysis with physical experiment. Theexperiment data is used as the reference, which verifies the validation of new method andthe accuracy of new model. The research contents of this thesis are shown as following:(1)Induce the two freedom degree suspension model considering the nonlinearcharacteristic, providing the theoretical calculation method of offset frequency anddamping ratio. To conquer the deficiency of current calculation method of damping ratio, anew damping ratio calculation method is derivate. In this method, the area method isemployed to calculate the damping ratio, which eliminates the false peak circumstance inthe logarithmic decrement method, so as to improve the estimation accuracy of dampingratio.(2)The sprung mass of automotive with independent suspension may not be calculatedas the sum of each component mass. To avoid the nonlinear characteristic of tyre, asimplified model is proposed, in which the acceleration of wheel center and vehicle bodyobtained by experiment are used to estimate the sprung mass and unsprung mass. Thismethod provides higher accuracy of mass estimation, which has important influence ofsuspension analysis design and research.(3)Build a new nonlinear smooth hysteresis model of rubber bushing, combining theexperiment dates to determine the initial value of parameters, solving the bushingrestoring force. The parameters sensitivity analysis of model is implemented, neglectingthe cross affection of parameters, determining the influence extent to model response ofmainly parameters, which provides reference to the possible model mending. Combiningthe test results of static stiffness and dynamic stiffness, a mended model considering thepreload effect is proposed, which extends the application range of nonlinear smoothhysteresis rubber bushing model. The genetic algorithm is utilized to estimate theparameters obtaining the exact value of parameters, and then compare the simulation results with experiment result verifying the validation and accuracy of model.(4)A new experiment method is used, where the simple and cheap sensors areemployed, testing some more approachable physical quantities such as acceleration,displacement and strain and then back-calculating the six component forces of spindleload. After the six component forces of spindle load are obtained, the forces of joints arecalculated through the multi-body dynamics suspension model, which are compared withthe experiment data to test the validation of reverse solving process and results. Based onthese results, the fatigue lives of chassis components are calculated, and the optimizationchoosing the stiffness of key bushinges of suspension as design variables is implemented,which improves the fatigue lives of chassis components.This thesis is focused on the automotive suspension. Combining some real situationsin suspension research and design, enrich the system of suspension research and design,which makes the process of suspension research and design more reasonable and morenormal, improving the quality and efficiency of suspension research and design. Thecreative method proposed in the thesis has large reality worth and promoting effect onsuspension research and design process.更多还原