【作者】 王伟；

【导师】 林棻；

【作者基本信息】 南京航空航天大学 ， 车辆工程， 2014， 硕士

【摘要】 第三代轿车轮毂轴承是汽车的重要零部件，由于其结构新颖、运行工况恶劣且使用广泛，针对其开展力学性能分析及优化设计具有重要意义。本文首先针对轮毂轴承开展静力学分析。采用Catia建立轮毂轴承三维模型，基于Hypermesh及Ansys生成与轮毂轴承转弯工况相等效的有限元模型，考察轮毂轴承单元的力学性能。将仿真结果与力矩刚性试验结果进行比对，验证了有限元分析的正确性，精确地预测了轮毂轴承的力学性能。在对轮毂轴承静力学分析的基础上，基于Ansys/Ls-dyna开展了轮毂轴承在低速工况下的显式动力学分析，考察了轮毂轴承主要部件的速度场、应力场以及加速度场的分布形式，同时将仿真值与解析解进行比对，验证仿真结果的正确性。在此基础上，综合对比了轮毂轴承在低速、中速以及高速状态下的动态特性，分析了轮毂轴承转速对各部件应力场以及加速度场的影响。最后，针对轮毂轴承进行多目标优化，建立轮毂轴承优化设计数学模型，选取疲劳寿命、磨损寿命以及旋滚比作为目标函数，以轮毂轴承结构参数作为设计变量。引入惩罚函数处理约束条件，将原约束优化问题转化为无约束优化问题，采用带精英保留策略的非劣排序遗传算法(NSGA-II)进行轮毂轴承多目标优化设计。优化结果表明，各目标性能均得到不同程度的改善，优化效果显著。最后通过有限元仿真对优化前后轮毂轴承的应力及变形情况进行对比，验证了优化设计的正确性。更多还原

【Abstract】 The third generation wheel hub bearing is one of the most important parts of the car. Due to itsnovel structure, poor working conditions and widely usage, carrying out its mechanical propertyanalysis and optimization design is of great significance.Firstly, static analysis of wheel hub bearing is conducted. Geometric model is created by Catia.And the finite element model is established by Hypermesh based on the actual cornering conditionmodel of wheel hub bearing. And mechanical properties of wheel hub bearing can be calculated byAnsys. Then, the simulation results are compared with the results tested by rigid torque testingmachine. It verifies the correctness of the finite element model. And the mechanical properties of thewheel hub bearing are accurately predicted.Based on the static analysis, explicit dynamic analysis of wheel hub bearing is carried out in lowspeed working condition by Ansys/Ls-dyna. The stress field, velocity field and acceleration field arestudied under this condition. And the simulation results are compared with the analytical solution toverify its correctness. Based on the above study, wheel hub bearing’s dynamic characteristics arecompared in the low-speed, medium-speed and high-speed conditions. And the influences to the fieldsare analyzed.At last, multi-objective optimization for the third generation wheel hub bearing is conducted.Fatigue life, abrasion life and spin roll ratio are considered as the optimization targets. And theoptimum design model is established. Penalty function is introduced to deal with constraints.Multi-objective optimization design is calculated by NSGA-II. The performances of wheel hubbearing have been improved in different degrees. Finally, through the finite element analysis, thestress and deformation of the pre-optimization structure are compared with the optimization one toverify the correctness of optimization.更多还原