基于四阶矩的机械可靠性相关研究

发布时间：2018-05-14 17:24

本文选题：四阶矩 + 可靠性设计　；参考：《太原科技大学》2011年硕士论文

【摘要】：可靠性作为机械产品质量特性之一,已经备受广大用户的关注。高可靠性的机械产品不仅能够使企业得到良好的经济效益,还能在市场竞争中获得良好的信誉。鉴于实际工程数据属于小样本且样本数据可以同时服从多种分布函数,本文主要开展了以下三个方面的研究工作。首先,将样本数据的前四阶矩与泰勒级数、Edgeworth级数相结合,提出了一种基于样本前四阶矩计算机械零件可靠度的方法,建立了机械零件可靠性单目标优化设计和多目标优化设计的数学模型,然后在MATLAB环境下编写M文件,利用MATLAB自带的优化工具箱,以机械典型零件为例进行了优化设计,并用蒙特卡罗法进行了验证。其次,鉴于实际工程当中随机变量小样本数据可以服从多种分布形式,工程中一般多以随机变量服从正态分布予以计算,提出利用ANSYS软件对工程实际机械所受随机变量服从任意分布函数进行灵敏度分析,研究了各个随机变量对机械可靠度的影响程度。以球形压力容器和简支梁为例予以分析,确定了各个随机变量对压力容器和简支梁的影响程度。然后提出基于四阶矩的可靠度灵敏度分析方法,以球形压力容器为例进行了分析,得到了与实际一致的结果。最后,在总结前人有关机械稳健性设计的基础上,提出了基于质量损失函数与实际加工工艺尺寸误差相结合的一种稳健设计方法,并结合MATLAB优化工具箱中的优化函数,以悬臂梁为例予以计算。
[Abstract]:As one of the quality characteristics of mechanical products, reliability has attracted the attention of customers. High reliability mechanical products can not only make enterprises get good economic benefits, but also gain good reputation in market competition. In view of the fact that the actual engineering data belong to small samples and that the sample data can be applied to a variety of distribution functions at the same time, the following three aspects of research work are mainly carried out in this paper. Firstly, combining the first four moments of the sample data with the Taylor series Edgeworth series, a method for calculating the reliability of mechanical parts based on the first four moments of the sample is proposed. The mathematical models of reliability single objective optimization design and multi objective optimization design of mechanical parts are established. Then M files are written in MATLAB environment. The optimization toolbox of MATLAB is used to optimize the design of typical mechanical parts. The results are verified by Monte Carlo method. Secondly, in view of the fact that the small sample data of random variables can be obtained from various distribution forms in practical projects, in general, in engineering, random variables are usually calculated by using normal distribution. The sensitivity analysis of random variables received by engineering machinery from arbitrary distribution function is proposed by using ANSYS software, and the influence of each random variable on mechanical reliability is studied. Taking spherical pressure vessel and simply supported beam as examples, the influence degree of each random variable on pressure vessel and simply supported beam is determined. Then a reliability sensitivity analysis method based on the fourth order moment is proposed. The spherical pressure vessel is taken as an example and the results are in agreement with the actual results. Finally, a robust design method based on the combination of mass loss function and actual machining process dimension error is proposed based on summarizing the previous researches on mechanical robustness design, and combined with the optimization function in MATLAB optimization toolbox. The cantilever beam is taken as an example.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH122;TB114.3

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