基于加速寿命试验的滚动轴承寿命预测研究

发布时间：2018-05-08 02:31

本文选题：滚动轴承 + 三参数weibull分布　；参考：《国防科学技术大学》2012年硕士论文

【摘要】：滚动轴承是机械工业使用广泛、要求严格的配套件和基础件，被人们称为机械的关节。作为装备的关键部件，滚动轴承一旦失效将严重降低装备的战斗力，甚至造成灾难性事故。滚动轴承的寿命是其耐久性的重要统计指标。有效地预测滚动轴承的寿命对于了解机械产品健康状况并制定优化的维修策略具有重要意义。本文围绕滚动轴承的寿命预测问题，建立了基于加速寿命试验的预测方法，并进行了工程应用及实例验证，主要研究内容如下：（1）在简要归纳滚动轴承工作原理和失效形式的基础上，深入分析滚动轴承疲劳失效机理。与传统研究中滚动轴承疲劳寿命服从Weibull分布假设不同，本文从失效分析和数据拟合的角度解释为什么滚动轴承疲劳寿命服从三参数Weibull分布，为后续数据分析方法研究奠定基础。（2）对目前主要的三参数Weibull分布参数估计方法进行了简要介绍，并针对这些方法存在的不足提出了一种新的易于工程应用的三参数Weibull分布参数估计方法，为后续竞争失效场合恒定应力加速寿命试验统计分析方法研究奠定基础。（3）针对目前三参数Weibull分布在竞争失效场合研究中的问题，建立三参数Weibull分布及竞争失效场合恒定应力加速寿命试验数据分析方法，在参数估计过程中，通过引入基于EM算法的极大似然估计，解决了直接极大化似然估计对初始值比较敏感的缺点。仿真结果表明，即使在失效模式未确定比例为0.7的情况下，仍能得到很好的估计效果。（4）在加速寿命试验相关实施标准的基础上，制定了详细的滚动轴承加速寿命试验方案，提出了通过应用滚动轴承最大接触应力计算公式进行外加负载上限计算的方法，并提出试验条件一致性检验细则，确保滚动轴承失效机理相同，使得试验数据之间具有可比性，为滚动轴承加速寿命试验的实施提供理论指导。（5）以6205深沟球轴承为对象进行了工程应用及试验验证。依据滚动轴承加速寿命试验方案，对6205深沟球轴承加速寿命试验进行了统计分析，得出该轴承的可靠性评估及寿命预测结果。结果表明，在三参数Weibull分布基础上，同时考虑竞争失效的情况下，，可靠性评估及寿命预测结果更符合实际情况，所得结果更加准确，从而验证了本文方法的可行性和有效性。综上所述，本文从理论分析与应用验证相结合的角度研究了基于加速寿命试验的滚动轴承工作寿命预测方法。本文的研究成果对于滚动轴承的可靠性评估与寿命预测具有重要的推动作用，并对加速寿命试验技术在其它机械产品可靠性评估与寿命预测领域中的研究和应用具有一定的借鉴意义。
[Abstract]:Rolling bearings are widely used in mechanical industry and require strict fittings and basic parts. They are called mechanical joints. As the key component of the equipment, the rolling bearing failure will seriously reduce the combat effectiveness of the equipment, and even cause catastrophic accidents. The life of rolling bearing is an important statistic index of its durability. It is important to predict the life of rolling bearings effectively for understanding the health status of mechanical products and making optimal maintenance strategies. In this paper, the prediction method based on accelerated life test is established around the life prediction problem of rolling bearing, and the engineering application and example verification are carried out. The main research contents are as follows: On the basis of summarizing the working principle and failure form of rolling bearing, the fatigue failure mechanism of rolling bearing is analyzed. Different from the Weibull distribution assumption in traditional research, this paper explains why rolling bearing fatigue life suit is distributed from three parameters Weibull distribution from the point of view of failure analysis and data fitting, which lays a foundation for the study of subsequent data analysis methods. In this paper, the main three parameter Weibull distribution parameter estimation methods are briefly introduced, and a new three parameter Weibull distribution parameter estimation method which is easy to be used in engineering is put forward in view of the shortcomings of these methods. It lays a foundation for the statistical analysis of constant stress accelerated life test in subsequent competitive failure situations. 3) aiming at the problem of three-parameter Weibull distribution in the research of competitive failure situation, a method for analyzing the data of three-parameter Weibull distribution and constant stress accelerated life test in competitive failure situation is established. In the process of parameter estimation, By introducing maximum likelihood estimation based on EM algorithm, the shortcoming of direct maximization likelihood estimation is solved that is sensitive to initial value. The simulation results show that even if the failure mode has an uncertain ratio of 0.7, it can still get a good estimation effect. On the basis of the relevant implementation standards of accelerated life test, a detailed scheme of rolling bearing accelerated life test is formulated, and a method for calculating the upper limit of applied load by applying the formula of maximum contact stress of rolling bearing is put forward. The detailed rules of test conformance inspection are put forward to ensure that the failure mechanism of rolling bearing is the same, so that the test data are comparable, which provides theoretical guidance for the implementation of rolling bearing accelerated life test. Taking 6205 deep groove ball bearing as the object, the engineering application and test verification are carried out. According to the accelerated life test scheme of rolling bearing, the accelerated life test of 6205 deep groove ball bearing is statistically analyzed, and the reliability evaluation and life prediction result of the bearing are obtained. The results show that on the basis of three-parameter Weibull distribution and considering the failure of competition at the same time, the results of reliability evaluation and life prediction are more consistent with the actual situation, and the obtained results are more accurate, which verifies the feasibility and effectiveness of the proposed method. To sum up, this paper studies the working life prediction method of rolling bearing based on accelerated life test from the point of view of theoretical analysis and application verification. The research results in this paper play an important role in the reliability evaluation and life prediction of rolling bearings. It can be used for reference in the research and application of accelerated life test technology in the field of reliability evaluation and life prediction of other mechanical products.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.33;TB114.3

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