共查询到20条相似文献,搜索用时 218 毫秒
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采用NACA四位数翼型的中弧线结合厚度分布的参数化表达式获得翼型的设计参数,结合经过标准算例验证的基于SST-kw湍流模型的RANS(雷诺平均N-S方程)计算方法,实现对于翼型的黏性流场分析。采用拉丁超立方法确定DOE(实验设计)中的样本空间,依据约束条件筛选可行解集,使用响应面作为代理模型,采用NLPQL(非线性序列二次规划法)求解代理模型中的最优解,对最优解所在设计点进行单独验证,以此构成翼型的气动优化设计框架。在该框架下针对翼型的特定亚音速工况,开展减阻的优化设计,以翼型最大相对厚度、最大相对弯度以及最大弯度位置作为设计变量,阻力系数作为优化目标函数,并以升力和厚度限制作为气动和几何的约束条件。翼型在设计工况下的阻力系数优化结果与其他文献中的CST(类/形函数转换)参数化方法相比,设计变量更少且优化结果相当,表明该优化设计框架相对高效,具有实用价值。 相似文献
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基于6σ的稳健优化设计在薄板冲压成形中的应用 总被引:9,自引:5,他引:9
薄板冲压成形过程中,其设计变量和噪声因素都具有一定的波动,都存在不确定性。传统的优化设计由于忽略不确定因素的影响,当设计变量产生波动时,往往会导致设计最优目标超出约束界限或者目标函数对设计变量的波动极为敏感,从而使设计失效。采用自主开发的STLMesher软件建立了模具的参数化模型,在此基础上将试验设计、能代表实际冲压过程精度较高的近似模型和蒙特卡罗模拟技术相结合,构造了基于产品质量工程的6σ稳健优化设计方法。该方法在设计初始阶段就考虑了各种不确定因素的影响,因此在获得近似最优解的同时能够提高设计变量的可靠性和目标函数的稳健性,大幅提高产品的质量。在优化过程中调用的是近似模型,能大大减少调用有限元模型的次数,提高优化效率。算例表明,该方法具有较高的精度和较强的工程实用性。 相似文献
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介绍了基于多学科优化平台Isight的机车车体轻量化优化方法,该方法包括确定设计变量和约束变量、选定参与优化计算的设计变量、优化解的确定方法、优化解全工况验证等主要内容,使用该方法对某机车车体进行优化,车体减重达到10%,减重效果显著。 相似文献
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复合材料起落架舱门结构优化设计 总被引:1,自引:0,他引:1
基于有限元软件ANSYS建立复合材料起落架舱门参数化有限元模型,基于三明治夹芯板理论将蜂窝芯层等效为均质的厚度不变的层板,以蜂窝夹芯高度与复合材料面板各铺层厚度为设计变量,以铺层板、蜂窝夹芯的强度,结构稳定性以及结构刚度为约束函数,以结构质量最轻为目标函数,基于ANSYS优化模块首先选择零阶法进行优化得到粗略解,其次选择一阶梯度优化法进一步对夹层结构进行优化设计,得到最优蜂窝芯子厚度、蒙皮各铺层厚度. 相似文献
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针对以多工况载荷下结构柔顺度最小为目标函数,结构体积为约束条件的优化问题,提出了一种新的拓扑优化求解方法。首先,参考限界公式法,通过一个限界变量将原多个目标函数转化为约束条件,引入一个新的该限界变量的二次函数作为目标函数。同时,结合变体积约束限技术,建立新的近似拓扑优化模型。然后,基于有理近似材料模型和移动渐进线方法,给出了目标函数和约束函数及其导数的显式近似式。利用光滑化对偶算法,构建了具有收敛性的多工况载荷下连续体结构的柔顺度拓扑优化算法。给出的算例结果表明,与现有方法比,该方法可获得更优解或可高效地获得相同的优化解。且所提方法可稳健地获得清晰0/1分布的优化结构拓扑。 相似文献
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提出第二代非劣排序遗传算法(NSGA-II)结合响应面法(RSM)-径向基神经网络方法(RBF)混合近似模型和逼近理想解排序(TOPSIS)方法对某乘用车后排座椅进行结构-材料一体化多目标轻量化设计研究。结合有限元理论建立仿真模型,并通过行李箱碰撞试验验证仿真模型的正确性,根据工程经验和座椅靠背骨架吸能分析确定了6个优化部件厚度、材料的设计变量及取值范围;采用RSM-RBF混合近似模型方法拟合设计变量与响应之间的关系;利用NSGA-Ⅱ算法对优化问题进行求解,得到Pareto最优解集。最后采用基于熵权TOPSIS方法对Pareto最优解集进行排序确定最佳折中解。结果表明:在满足各项安全性能法规的前提下,乘用车后排座椅减重3.57 kg。 相似文献
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传统的减速器设计以设计者的经验为基础,设计方案往往不是最优的,而对于三级斜齿圆柱齿轮减速器的设计,这一缺点更突出。为保证齿轮的承载能力和性能规格,实现三级减速器的体积、重量最小,文中以优化设计理论为指导,以各级齿轮中心距之和最小为目标函数,通过变量的选取、约束条件的确定,建立了三级斜齿圆柱齿轮减速器的优化设计数学模型,借助MATLAB优化工具箱寻优计算,简化了复杂的编程,提高了设计效率和质量。 相似文献
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Kwang-Ho Kim Jong Cheon Park Yong S. Suh Bon-Heung Koo 《The International Journal of Advanced Manufacturing Technology》2017,88(5-8):1333-1344
A new robust optimal design methodology has been developed and applied to the design of plastic injection molding products. Taguchi’s robust design method and an optimal design search algorithm are integrated with a commercial CAE simulation tool. A direct search-based optimization procedure is implemented with the considerations of process variations as well as uncontrollable noise variables. The Interactive Design Space Reduction Method (IDSRM) based on orthogonal arrays for design of experiments is developed as a general optimization tool. Using the system, designers can interactively adjust the design space during the searching process for the optimal solution based on the outcomes of the experiments. The developed methodology is applied to an industrial application: a molding process design of an automobile front bumper to minimize the weldline, a form defect of plastic parts. Compared with the initial design solution, the optimized design aided by the proposed methodology shows a more efficient and better result in terms of design robustness against process variations. 相似文献
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J. Zhang G. F. Ding Y. S. Zhou J. Jiang X. Ying S. F. Qin 《The International Journal of Advanced Manufacturing Technology》2014,73(1-4):251-265
As a complex mechatronic system, the running stability, safety, and comfort of high-speed train are affected by many design variables. It is of great difficulty to identify a set of effective design parameters to optimize its running performance. The current simulation systems like the SIMPACK can simulate the running dynamics, but cannot be used effectively for optimal design of the train and rail system because there are too many design variables being supposed to be dealt with. Therefore, there is a need to make a software solution from simulation analysis to optimal design so that the computer-aided design (CAD) and engineering (CAE) can be integrated into an integral design process. This paper presents a new method to identify the key design variables against the running performance indicators based on the sensitivity analysis, which in turn bases itself on simulation-oriented surrogate models. In this way, the optimal design of a high-speed train can be successfully conducted because (1) the surrogate model can reduce the simulation time greatly and (2) the design variable space with the key variables will be reduced significantly. The research shows that this method is of practical significance for speeding up the design of high-speed train or similar complex mechatronic systems. 相似文献
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介绍了机床主轴的结构,建立了以质量最轻为目标函数的优化模型,运用MATLAB优化工具箱中的fmincon函数对其进行优化设计。通过对已有的机床主轴实例进行优化求解和分析,对比优化前后的数据信息,表明优化之后的机床主轴质量更轻,且编程简单,设计效率高。最后绘出了实例的各设计变量和目标函数之间的关系图,并对MATLAB求优的特点进行总结。 相似文献
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Hee Seung Hong TaeWon Seo Dongmok Kim Sunho Kim Jongwon Kim 《Journal of Mechanical Science and Technology》2013,27(1):125-132
Transporting heavy packages while climbing stairs can be a very difficult or dangerous task. In situations where this task is frequently required such as construction sites, workers would use equipment such as a back rack for convenience, but still it becomes a difficult task as the weight increases. In this paper, we propose a stair climbing hand-carrying cart based on the rocker-bogie mechanism. We conduct an optimal design of the kinematic variables of the rocker-bogie mechanism for stable stair climbing using Taguchi methodology. Fluctuations and a tilted angle during stair climbing are considered to formulate the objective function. Three different shapes of typical stairs are selected as user conditions to determine a robust optimal solution. The results are verified by experiments using a testing set-up of three stair profiles, and the experimental results are compared with simulation. We expect that the results of this research can be applied to stair climbing robot design. 相似文献
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为快速获得改善车辆横向平稳性的最优悬挂参数,提出基于自适应模拟退火算法和非线性序列二次规划算法的组合优化策略对动车组悬挂参数进行优化设计。建立动车组动力学模型,利用最优拉丁超立方抽样方法选取对横向平稳性影响较大的悬挂参数作为设计变量;以横向平稳性为目标函数构建Kriging代理模型,并利用可决系数检验代理模型精度;采用自适应模拟退火算法对代理模型进行全局范围内初步寻优,在初步最优解的基础上采用非线性序列二次规划算法进行局部空间精确求解。研究结果表明,基于Kriging代理模型和组合优化策略的优化效率明显提高,车辆横向平稳性得到显著改善,并且优化前后运行稳定性均满足要求。 相似文献