刚柔耦合模型汽车后扭力梁振动疲劳优化分析

发布时间：2018-06-28 01:51

本文选题：后悬架扭力梁 + 有限元　；参考：《湖南大学》2016年硕士论文

【摘要】：汽车由成千上万个零部件组成,其中悬架是汽车结构中重要的构件,其性能对整车的乘坐舒适性和安全性起着主要的作用,尤其是悬架后扭力梁因价格低廉结构简单实用在紧凑型家用轿车中得到普遍应用。车辆运行时,来自于路面激励的作用直接传递到悬架后扭力梁上,会发生疲劳损伤,影响其使用寿命。目前,很多厂家进行大量的实验来求疲劳寿命,费用大,时间长。现有部分人尝试采用理论和数值分析方法对其进行了探讨,但只局限于单个因素,没有联合实验结果和数值计算再对其进行系统分析。本文基于大量的文献调研,采用疲劳寿命理论分析、有限元和实验验证方法,对后悬架扭力梁结构进行了分析与优化。主要工作和结论如下:(1)基于疲劳损伤理论,对某车型的后悬架扭力梁进行力学分析,揭示了其疲劳寿命的影响因素;(2)基于有限元理论,对后悬架扭力梁模态和准静态下受力特点进行了较为详细的分析,得出其一阶模态偏低,接近于路面激振频率,造成结构强度不足;(3)基于后悬架扭力梁的受力特点,建立了整车刚柔耦合模型,根据实测采集得到的强化路面谱,得到了后悬架扭力梁的各阶模态位移历程;(4)基于疲劳寿命分析理论,结合各阶模态位移历程和材料S-N曲线,分析后悬架扭力梁的疲劳寿命,并进行了实验对比验证;(5)基于疲劳分析结果,对后悬架扭力梁的结构和悬架参数进行了优化,优化的悬架扭力梁的寿命得到提高。
[Abstract]:The automobile is composed of thousands of parts and components, among which suspension is an important component in the automobile structure, and its performance plays an important role in the ride comfort and safety of the whole vehicle. Especially, the rear torsion beam of suspension is widely used in compact passenger cars because of its low cost and simple structure. When the vehicle is in operation, the effect of the road excitation is transferred directly to the torsion beam behind the suspension, which will cause fatigue damage and affect its service life. At present, many manufacturers carry out a large number of experiments to obtain fatigue life, high cost and long time. Some people have tried to use the theory and numerical analysis method to study it, but it is limited to a single factor, without the joint experimental results and numerical calculation to carry on the systematic analysis. Based on a large number of literatures, this paper analyzes and optimizes the torsion beam structure of the rear suspension by using the fatigue life theory analysis, finite element method and experimental verification method. The main work and conclusions are as follows: (1) based on the fatigue damage theory, the mechanical analysis of the rear suspension torsion beam of a certain vehicle is carried out, and the influencing factors of its fatigue life are revealed; (2) based on the finite element theory, the fatigue life of the rear suspension torsion beam is analyzed. The modal and quasi-static stress characteristics of the rear suspension torsion beam are analyzed in detail, and the results show that the first order mode is lower, which is close to the exciting frequency of the road surface, resulting in the insufficient structural strength. (3) based on the stress characteristics of the rear suspension torsional beam, The rigid-flexible coupling model of the whole vehicle is established, and the displacement history of each order of the rear suspension torsional beam is obtained according to the enhanced road surface spectrum collected from the measured data. (4) based on the theory of fatigue life analysis, the displacement history and the S-N curve of the material are combined with each order modal displacement history. The fatigue life of the rear suspension torsion beam is analyzed, and the experimental results are compared. (5) based on the fatigue analysis results, the structure and suspension parameters of the rear suspension torsion beam are optimized, and the life of the optimized suspension torsion beam is improved.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.33

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