【作者】 王健；

【导师】 孙志礼；

【作者基本信息】 东北大学 ， 机械设计及理论， 2014， 硕士

【摘要】 本文以Copula相关性理论为基础,通过分析以往基于Copula模型考虑机械系统中故障相关性的不足提出基于复合Copula函数的能够反映部件间不同相关程度的相关性模型,并将该模型应用于贝叶斯网络中考虑贝叶斯网络中底事件相关性,为准确评估系统可靠性提供理论依据。本文的主要研究内容如下：(1)推导了基于Copula理论并联和串联系统的可靠度计算模型,该系统可靠度计算模型中只含有多维差分计算；对常用的Copula模型参数估计方法进行改进,改进的二阶参数估计法能够借助贝叶斯理论估计Copula模型中的参数；通过实例分析提出基于复合Copula函数的系统可靠度评估方法,该方法较以往模型拟合精度有明显提高。(2)给出了确定复合Copula模型结构的算法,该算法基于最大势搜索算改进而来,易于程序化；将复合Copula模型引入贝叶斯网络中,并给出考虑贝叶斯网络底事件相关性的系统可靠度计算方法；通过实例说明复合Copula模型能够较好刻画变量间的相关关系,秩相关系数较线性相关系数具有明显优势。(3)提出基于费用和设备可靠度的预防性维修周期模型,模型中综合考虑设备预防性维修费用、事后维修费用、正常使用收益和可靠度,以单位时间收益最大化为优化目标确定预防性维修周期。本章最后将该模型进行拓展,用于确定设备的预防性维修周期和更换周期,为建立复杂多设备系统维护策略奠定基础。更多还原

【Abstract】 In this paper, the previous Copula model is analyzed and its drawback is found. A composite Copula model is proposed based on the Copula theory to reflect different relevant information among random variables in mechanical system. The proposed model is applied to Bayesian Network to analyze the correlativity of bottom events in BN, which is helpful for assessing the reliability of mechanical system.(1) The reliability models of series system and parallel system is derived based on Copula theory. There is only some difference in the derived model instead of.multi dimensional integral. Copulas connect of commonly used model parameter estimation method is improved, and the improved method can estimate parametric with the help of Bayesian approach. A composite Copula model is proposed by a example. The composite model is more accurate than conventional one.(2) The structure of composite Copula can be confirmed based on maximum cardinality search algorithm. The composite Copula model is used in BN to consider the correlativity of bottom events, and the corresponding reliability computing method is proposed. Through the examples of composite copulas connect model can better describe the correlation between variables. Rank correlation coefficient of the linear correlation coefficient has the obvious advantage.(3) Based on cost and equipment reliability model of preventive maintenance cycle is proposed in which equipment preventive maintenance cost, maintenance cost of normal use, and reliability are considered To maximize earnings per unit time. This model is expanded, and is used to determine the equipment preventive maintenance cycle and replacement cycle. The expanded model is the foundation for building maintenance strategies model more complex system including equipments.更多还原