同轴式二级圆柱齿轮减速器的优化设计*

在系统研究二级圆柱齿轮减速器优化设计目标、设计变量和约束条件的基础上,以同轴式二级圆柱齿轮减速器的中心距与大齿轮分度圆直径之积最小作为设计目标,建立了齿轮减速器优化设计的数学模型。利用MATLAB的优化工具箱,对减速器进行优化设计,得出了优化结果。实例计算表明,优化结果明显好于常规设计方案。     

齿轮减速器的最优化设计

在齿轮减速器优化设计目标函数建立、设计变量选取和约束条件确定的基础上,建立其优化设计数学模型,利用MATLAB的优化工具箱对齿轮减速器进行优化设计,并通过实例与常规设计结果进行了分析。优化结果表明采用MATLAB算法求解优化设计问题,算法有效可靠且优于常规设计。     

摆动活齿减速器的模糊稳健优化设计

应用基于正交设计的稳健设计法，建立了摆动活齿减速器的优化设计模型，对摆动活齿减速器进行了模糊稳健优化设计，应用模糊综合评判法对该优化设计的结果进行评判，得到了该减速器设计变量的稳健优化设计最优组合。     

圆柱齿轮减速器的优化设计

以二级圆柱齿轮减速器的总中心距最小作为设计目标,选取齿轮齿数、模数、传动比和螺旋角作为设计变量,建立了齿轮减速器优化设计的数学模型,应用复合形法对减速器进行优化设计,得出了优化结果.实例计算表明,采用复合形法得出的优化结果明显好于常规设计方案.     

三级齿轮传动减速器的优化设计

本设计采用混合罚函数法对三级齿轮传动减速器进行优化设计,由计算机算出最优解,与常规设计比较,减速器尺寸降低了８％。该文应用的混合罚函法优化程序在计算速度方面有较大改进。此文主要阐述工程数学模型的建立和优化结果分析两部分,对三级齿轮减速器参数的优化设计进行了初步探讨。     

基于UGNX的减速器壳体轻量化设计

实现减速器壳体轻量化设计是节约成本、减轻能耗的有效途径。文中通过对二级减速器壳体原始设计进行静力学有限元分析,发现减速器壳体的静强度和安全系数远远小于许用值,导致材料严重浪费。在此基础上基于机械优化设计理论,采用几何优化设计方法,以减速器壳体壁厚、加强筋厚度以及上下凸台的壁厚为设计变量,以减速器壳体质量最小为优化目标,利用UGNX仿真环境对减速器壳体进行优化仿真计算。经过优化后,减速器壳体质量减轻了24.54%。此研究结果为轻量化设计提供了理论参考。     

模拟退火算法在减速器优化设计中的应用

根据模拟退火算法理论知识,建立了减速器优化设计的目标数学模型,确定优化设计时的约束条件,阐述了基于模拟退火算法减速器优化设计中的关键技术.并通过实例说明,采用模拟退火算法对减速器进行优化,可以使减速器设计得到显著的优化.     

行星齿轮减速器优化设计方法及应用

对行星齿轮减速器进行优化设计分析,建立了优化设计的数学模型,确定优化设计的约束条件,采用数学优化法对行星减速器进行优化设计,并通过实例说明,采用数学优化法可以得到更加优化的结果。     

基于Hopfield神经网络摆动活齿减速器模糊稳健优化设计

文章应用Hopfield神经网络稳健优化设计方法,建立了摆动活齿减速器优化设计数学模型。提出了优化设计方法。还对Hopfield神经网络方法进行优化计算,结果表明得到了减速器设计变量的稳健优化设计最佳组合。     

基于NSGA-Ⅱ的行星减速器多目标优化设计

为提高行星减速器工作能力,以齿轮强度和减速器体积为优化目标,对行星减速器进行多目标优化设计。以矿用提升绞车中的NGW型行星减速器为优化对象,以中心太阳轮尺寸参数为优化设计变量,建立配齿条件、齿面接触强度及工作参数等约束条件,构建多目标优化设计模型。利用带精英策略的非支配排序遗传算法(NSGA-II)对多目标优化模型进行优化计算,得到优化目标的帕累托(Pareto)最优解分布。通过对比得到优化目标间的相互影响规律,利用模糊集合理论从最优解集中选择出合理参数作为最终设计结果。分析结果表明本文提出的优化设计方法提高强度的同时,有效减小减速器体积,实现了行星减速器的多目标优化设计。     

月球探测器软着陆最优控制

研究了一种应用非线性规划求解有限推力作用下月球探测器软着陆最优控制问题的方法。从庞德里亚金极大值原理出发,将有限推力作用下月球软着陆问题转化为两点边值问题;在考虑边界条件及横截条件的前提下,将两点边值问题转化为针对共轭变量初值和末时刻的优化问题;而后应用非线性规划方法求解形成的参数优化问题,为了降低初值猜测的敏感性,引入一种变换,用控制变量初值代替了共轭变量初值。仿真结果表明了所提设计方法是简单、有效的。     

基于Kriging插值和回归响应面法的冲压成形参数的优化及对比分析

首先采用拉丁方试验设计方法进行样本数据设计,同时,为了提高计算效率,将基于Kriging插值和响应面近似模型引入板料成形优化设计的复杂系统中,并基于初始化变量进行优化,采用Kriging插值和响应面近似方法对样本点和优化过程中形成的优化点重新进行响应面构造,以确定优化范围内新的初始值并将约束减小到一定范围;随后采用遗传优化算法对更新的设计变量初始值和约束范围进行优化。如此循环,直至得到最优解。计算结果表明,在汽车覆盖件行李箱盖的压边力、拉延筋阻力最优设置以及避免出现拉裂、起皱现象方面,Kriging插值近似建模技术优于多项式回归响应曲面近似建模技术,其预测精度高,自由度高,建模效率高。     

Systematic design space exploration and rearrangement of the MDO problem by using probabilistic methodology

This study proposes a probabilistic approach for systematic design space exploration and rearrangement. The stochastic quantities and qualities of design space are explored using a reliability index, and the design space is rearranged to a higher feasible region by using Chebyshev inequality. Four test cases composed of algebraic functions are used to investigate the validity of the proposed method. Results show that the converged design space can include the feasible region outside the initial design space to the rearranged design space. Moreover, the results show that the proposed method is applicable to the aircraft wing design optimization problem, which considers collaborative optimization with three subsystems, namely, aerodynamics, structure, and performance. Wing design optimizations are also performed separately for the initial and converged design spaces. The results indicate that the range obtained in the converged design space improved compared with that in the initial design space. In conclusion, the proposed design space rearrangement method was shown to have the capability to search for feasible regions that are excluded in the initial design phase.     

Reliability-based design optimization of slider air bearings

This paper presents a design methodology for determining configurations of slider air bearings considering the randomness of the air-bearing surface (ABS) geometry by using the iSIGHT. A reliability-based design optimization (RBDO) problem is formulated to minimize the variations in the mean values of the flying heights from a target value while satisfying the desired probabilistic constraints keeping the pitch and roll angles within a suitable range. The reliability analysis is employed to estimate how the fabrication tolerances of individual slider parameters affect the final flying attitude tolerances. The proposed approach first solves the deterministic optimization problem. Then, beginning with this solution, the RBDO is continued with the reliability constraints affected by the random variables. Reliability constraints overriding the constraints of the deterministic optimization attempt to drive the design to a reliability solution with minimum increase in the objective. The simulation results of the RBDO are listed in comparison with the values of the initial design and the results of the deterministic optimization, respectively. To show the effectiveness of the proposed approach, the reliability analyses are simply carried out by using the mean value first-order second-moment (MVFO) method. The Monte Carlo simulation of the RBDO’s results is also performed to estimate the efficiency of the proposed approach. Those results are demonstrated to satisfy all the desired probabilistic constraints, where the target reliability level for constraints is defined as 0.8.     

Topology optimization of material microstructures using energy-based homogenization method under specified initial material layout

Due to multiple local optimums in the society of periodic material microstructure deign using topology optimization, it is widely recognized that the initial microstructure configuration can significantly influence the optimal design. This study investigates the effect of different initial material layouts of microstructure unit cell upon the optimal design, and proposes a microstructure initialization scheme to alleviate the dependency of the optimal design on its initial design. The effective elastic properties of microstructures are evaluated by the efficient energy-based homogenization method. Topology optimization models are formulated to seek the best microstructures with the extreme properties or desired properties under the prescribed volume constraints. Several typical numerical examples are presented to demonstrate the effectiveness of the proposed scheme. Numerical results show that the proposed scheme can reduce the sensitivity of the optimal design upon optimization parameters and be beneficial to achieve a stable and rapid convergence.

     

基于响应面法的井下旋流分离器结构优化

基于数值模拟方法与中心组合设计方法,采用二阶多项式基函数构建了井下旋流分离器的结构参数与分离效率及底流压力损失间的数学关系模型。通过开展附加试验对模型预测值与数值模拟实际值进行对比,得出分离效率和压力损失的预测值与实际值的平均相对误差分别为0.104%和4.562%,验证了模型预测结果的准确性。针对响应面优化结果与初始结构开展分离性能对比研究,结果表明：当入口油滴粒径在50～500 μm范围内变化时,优化前结构的分离效率变化范围为58.92%～98.56%,优化后结构的分离效率变化范围为60.35%～99.48%;当入口含水率在94%～99%范围内变化时,优化前结构的分离效率由74.61%提高到88.07%,优化后结构分离效率由75.26%提高到91.56%。在不同粒径及含水率条件下,优化后结构均呈现出了明显的高效性及适用性。     

楔环连接结构两种有限元优化设计方案研究

利用APDL语言对ANSYS软件进行二次开发,建立楔环连接结构的参数化有限元模型。为了对该结构进行优化设计,以楔环径向和轴向尺寸为设计变量,以结构最大应力比为目标函数设计结构的增强优化方案,以结构的各件应力比差的平方和为目标函数设计结构的等强设计方案。采用基于共轭梯度法的一阶优化方法求解,增强优化的结果表明,拉伸载荷下结构的最大等效应力降低21.1%,安全系数由1.08提高到1.37,可达到增强设计目的;等强优化的结果表明,优化后结构各件应力比接近,应力比差的平方和从0.600降为0.067,可以达到等强设计目的。实践说明采用非线性有限元法和一阶优化法对连接结构进行优化能够取得预想的效果。     

某机动式雷达天线阵面结构优化设计方法研究

文中提出了机动式雷达天线阵面结构正向设计方法,对雷达天线阵面进行了轻量化设计.应用经典力学求解天线阵面在静力学工况下的最大应力和变形,将此作为优化约束条件,将阵面质量作为优化目标,建立天线阵面的数学模型,用遗传算法进行第1次设计优化,得到天线阵面的初始结构参数综合考虑静力学工况与动力学工况,进一步用ANSYS系统的APDL建立参数化有限元模型,进行第2次优化,得到天线阵面的结构参数.文中对某型号的机动式雷达天线阵面进行了正向设计,并将优化结果与该雷达现有设计结果进行了分析对比.结果表明该正向设计方法合理,轻量化效果明显.     

Metamodel-based global optimization using fuzzy clustering for design space reduction

High fidelity analysis are utilized in modern engineering design optimization problems which involve expensive black-box models.For computation-intensive engineering design problems,efficient global optimization methods must be developed to relieve the computational burden.A new metamodel-based global optimization method using fuzzy clustering for design space reduction(MGO-FCR) is presented.The uniformly distributed initial sample points are generated by Latin hypercube design to construct the radial basis function metamodel,whose accuracy is improved with increasing number of sample points gradually.Fuzzy c-mean method and Gath-Geva clustering method are applied to divide the design space into several small interesting cluster spaces for low and high dimensional problems respectively.Modeling efficiency and accuracy are directly related to the design space,so unconcerned spaces are eliminated by the proposed reduction principle and two pseudo reduction algorithms.The reduction principle is developed to determine whether the current design space should be reduced and which space is eliminated.The first pseudo reduction algorithm improves the speed of clustering,while the second pseudo reduction algorithm ensures the design space to be reduced.Through several numerical benchmark functions,comparative studies with adaptive response surface method,approximated unimodal region elimination method and mode-pursuing sampling are carried out.The optimization results reveal that this method captures the real global optimum for all the numerical benchmark functions.And the number of function evaluations show that the efficiency of this method is favorable especially for high dimensional problems.Based on this global design optimization method,a design optimization of a lifting surface in high speed flow is carried out and this method saves about 10 h compared with genetic algorithms.This method possesses favorable performance on efficiency,robustness and capability of global convergence and gives a new optimization strat