【作者】 樊牡丹；

【导师】 夏亚峰；

【作者基本信息】 兰州理工大学 ， 运筹学与控制论， 2012， 硕士

【摘要】 本文对载荷多次作用下的零件模糊可靠性进行了以下两方面的研究:(1)针对载荷和强度均为模糊变量,同时考虑载荷作用次数的情况下,运用载荷-强度干涉模型理论和模糊理论,建立了载荷多次作用下的零件模糊可靠度计算模型.在双状态假设下,给出了在相应截集水平下相应的概率分布密度函数为均匀分布、线性分布和截尾正态分布时,模糊可靠度的数字模拟解法和解析解法,并以均匀分布为例，在模糊状态假设的前提下,研究了零件可靠度的计算并给出了计算实例.(2)基于冲击模型理论,一方面,对于载荷多次冲击时,冲击次数和累积损伤都是随机模糊变量的冲击过程,研究了零件可靠度及计算并给出了算例.另一方面,运用数据拟合的方法,建立了以冲击次数为寿命度量指标的零件可靠度和失效率的计算模型.并对累积损伤带有模糊性的情况,研究了不同隶属函数形式下零件可靠度和失效率的变化规律.更多还原

【Abstract】 In this paper, we study the following two aspects about the fuzzy reliability of partsunder multiple loadings:(1) For the case of the load and strength which are fuzzy variables, and considering thenumber of loadings, we use the load-strength interference model theory and fuzzy theory, andthen we set up the fuzzy reliability calculation model for parts. In a state under the hypothesis,we give the digital simulation method and analytic method of the fuzzy reliability, and takinguniform distribution for example, when the density function of the corresponding probabilitydistribution are evenly distribution, linear distribution and tail normal distribution in thecorresponding cut sets level. In fuzzy state, we give the calculation of components reliabilityand numerical examples.(2) Based on the impact theory, on one hand, we give the calculation of componentsreliability and numerical examples, when the process of load acting is described with theshock process for the repeated impact load, which the accumulative damage is blurry. On theother hand, using the model data fitting method, we set up the reliability and failure ratecalculation model for parts, taking impact times as life measures. Based on the above, we givethe change rule of reliability and failure rate of parts in the different forms of membershipfunction, when the cumulative damage is fuzzy.更多还原