【作者】 张玉美；

【导师】 王智明；

【作者基本信息】 吉林大学 ， 机械工程， 2011， 硕士

【摘要】 本课题主要是根据实际需要选题,为降低产品的成本,根据车轮台架试验对车轮进行有限元分析及优化设计[1]。以某轿车的钢制车轮为分析对象,构建从产品建模、应力分析、模态分析、疲劳分析到优化设计为一体的仿真分析。为开发设计人员提供设计依据,使设计人员在产品开发之前就能够预测其应力分布、变形和使用寿命等,进而降低产品的开发周期和成本。具体研究工作如下:(1)本文的轿车车轮为两件式,包括轮辐和轮辋,轮辐和轮辋通过过盈装配及焊接连接。为了更好的模拟过盈装配对车轮的影响,应用弹塑性理论对车轮进行了过盈装配分析,分析结果中表明只有轮辋发生了塑性变形,但是经过后期的热处理等工艺,可以将过盈产生的残余应力消除。(2)对车轮的螺栓预紧力进行了模拟,采用梁单元来模拟螺栓,并用温度载荷法给梁单元施加预紧力,通过分析可知螺栓的预紧力对车轮的影响较小,可以忽略不计。(3)根据国家标准,对车轮进行了弯曲和径向应力分析,由于车轮具有对称性,所以对车轮进行了正对螺栓孔和正对两螺栓孔中间的两种工况的分析。在对车轮进行径向应力分析时,在不考虑应力集中的情况下,轮辐的危险点出现在螺栓孔处,轮辋的危险点出现在轮辋两边的凸起处,但车轮的整体强度足够。对于弯曲应力分析,因为螺栓孔处为加载位置,所以螺栓孔处出现了应力集中,除应力集中外,轮辐和轮辋都有一定的强度储备,车轮处于安全状态。为了后续仿真计算,提出了车轮简化模型,并验证了其简化的合理性。(4)由于车轮的破坏主要是弯曲疲劳破坏,所以为了深入研究车轮在弯曲疲劳试验下车轮的振动特性,对车轮进行了弯曲工况下的模态分析,并提取前12阶模态,分析结果表明,车轮振动特性符合要求。(5)为了更好地预测车轮的疲劳寿命,用ANSYS中的Fatigue模块对车轮进行了弯曲疲劳寿命分析[2],预测车轮的疲劳破坏位置和使用寿命,为设计人员提供指导意义。(6)利用ANSYS中的优化模块,对车轮的轮辐进行了优化设计,结果表明,在保证车轮不发生共振和疲劳破坏的前提下,优化后的车轮质量减轻了4.32%,材料得到了充分利用,达到了降低生产成本的目的。更多还原

【Abstract】 This topic is mainly according to actual needs to reduce the cost of the product, according to the wheel to wheel bench finite element analysis and optimization, the method is a collection of product modeling, stress analysis, model analysis, and fatigue analysis and optimization design as one of the simulation based on the car steel wheel. It can provides design basis for designers, makes the designers predict the stress distribution, deformation and service life before product development,then reducing product development cycle and cost. Specific studies are as follows:(1)This text of car wheel is two-piece, including the spoke and rim, the connection of spoke and rim through interfere fit and weld. In order to simulate the influence of interfere fit to wheel accurately; we used elastic-plastic theory to analyze. There is only plastic deformation on rim in the analysis results. But after the later heat treatment process, the interference can be generated by residual stress eliminated.(2)Simulated the preload of wheel bolts, using beam elements to simulate the bolts, and the beam elements were loaded by temperature load method. The result shows that the influence of bolts preload to the wheel is slight.(3)According to National Standards, analyze the bending and the radial stress of the wheel. Because of the symmetric of wheel, two analysis conditions were chosen, the wheel bolt holes and the middle of two bolt holes.When analyzed the radial stress, without considering the stress concentration in the case, the dangerous points of spoke appear on the bolt holes, and the dangerous points of rim appear on both sides of the protrusions.However, the overall strength of the wheel is enough.When analyzed the bending, because the bolt hole is loaded position, so there is a stress concentration around the bolt hole. Both of the spoke and rim have additional strength reserved except the stress concentration, so that the wheel is safe.Proposed the simplified model of the wheel for the simulation following, and verified the reasonableness.(4)For the main damage of wheel is bending fatigue, the modal analysis of wheel is discussed, which to study the vibration characteristics of the wheel in the bending fatigue test deeply. Extracting the preceding twelve models proved that the vibration characteristics of the wheel to meet the requirements there was no resonance upon the wheel.(5)In order to exactly predict the fatigue life of the wheel, we analyzed the bending fatigue life of the wheel using Fatigue in ANSYS,predicted the fatigue failure location and the wheel life, provided guidance for the designer.(6)Take use of the optimization module of ANSYS,optimized the wheel spoke. The result shows that the mass of spoke reduced by 4.32%.The material has been fully utilized to achieve lower the production cost.更多还原