基于近似模型的机车齿轮的可靠性优化设计

发布时间：2018-05-20 07:16

本文选题：齿轮 + 非概率可靠性优化　；参考：《湖南大学》2012年硕士论文

【摘要】：齿轮是在各种传动系统中应用最为广泛的一种传动机构。它依靠轮齿齿廓直接接触来传递空间任意两轴间的运动和力，并具有传递功率范围大、传递效率高、传动比准确、使用寿命长、工作可靠等优点。目前，我国列车的运行速度较之以前得到大幅提高，作为动力传动部件的变速齿轮，长期处于高速重载的工作环境中，容易出现齿面胶合及点蚀，因此齿轮的应力分析以及齿轮的啮合参数的优化是很有必要的。本文首先基于通用有限元软件ANSYS的参数化设计语言APDL建立了机车齿轮的参数化有限元模型，，然后在齿轮最大等效功率工作状态下仿真计算轮齿的接触应力和齿根弯曲应力。然后，以齿轮的啮合参数为设计变量，可靠度作为约束，以轮齿的接触应力、齿根弯曲应力及轮齿传动的重合度为优化目标，采用带有精英保持策略的非支配排序遗传算法（NSGA-II）对齿轮进行了优化。考虑到有限元模型比较复杂，为避免优化迭代过程中调用有限元计算应力会导致计算时间过长的问题，在一定仿真次数的基础上建立了轮齿有限元计算的代理模型，以提高计算效率。由于轮齿的载荷在齿轮传动中会随着振动和冲击发生变化，故将其作为一不确定因素考虑并用区间数来描述，相应的可靠性约束采用非概率可靠性指标算法求解。为了降低不确定性参数对轮齿应力变化幅度的影响，采用区间分析方法对齿轮进行了不确定多目标优化，并与可靠性优化进行了比较。最后，将优化的结果通过有限元仿真验证，轮齿的应力得到了有效的降低，说明优化结果是有效可行的。
[Abstract]:Gear is the most widely used transmission mechanism in various transmission systems. It relies on the tooth profile to transfer the movement and force between any two axes in space. It has the advantages of large transmission power range, high transmission efficiency, accurate transmission ratio, long service life, reliable operation and so on. At present, the running speed of train in our country has been greatly improved compared with before. As a power transmission component, the variable speed gear is in the working environment of high speed and heavy load for a long time, so it is easy to appear tooth surface gluing and pitting corrosion. Therefore, it is necessary to analyze the stress of gears and optimize the meshing parameters of gears. In this paper, the parametric finite element model of locomotive gear is established based on the parameterized design language APDL of the universal finite element software ANSYS, and then the contact stress and the tooth root bending stress of the gear tooth are simulated under the working state of the gear maximum equivalent power. Then, the gear meshing parameter is taken as the design variable, the reliability is taken as the constraint, the contact stress of the gear tooth, the bending stress of the tooth root and the coincidence degree of the gear tooth transmission are taken as the optimization objectives. The non-dominant sorting genetic algorithm (NSGA-II) with elite retention strategy is used to optimize gears. Considering the complexity of the finite element model, in order to avoid the problem that the calculation time is too long when the finite element calculation stress is used in the optimization iteration process, the agent model of the gear tooth finite element calculation is established on the basis of a certain number of simulation times. In order to improve the efficiency of calculation. Because the load of gear teeth changes with vibration and shock in gear transmission, it is considered as an uncertain factor and described by interval number, and the corresponding reliability constraints are solved by non-probabilistic reliability index algorithm. In order to reduce the influence of uncertain parameters on the change of stress amplitude of gear teeth, the method of interval analysis is used to optimize the gear with uncertain multi-objective, and compared with the reliability optimization. Finally, the optimization results are verified by finite element simulation, and the stress of gear teeth is reduced effectively, which shows that the optimization results are effective and feasible.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH132.41;U260.3

【参考文献】