This paper presents and analyses the internal and external efficiencies of equipment maintenance, and presents that the objective of maintenance is the maximum external efficiency. It defines generalized reliability d...This paper presents and analyses the internal and external efficiencies of equipment maintenance, and presents that the objective of maintenance is the maximum external efficiency. It defines generalized reliability degree of equipment and deduces the correspondent calculating method. It overcomes the defect that traditional calculating method of reliability degree has, which only considers the factor of time not function, therefore we establish a market decision model of equipment maintenance based on it. This model can determine the marginal efficiency of maintenance investment and critical value of generalized reliability degree when it reaches break-even point. After combining the equipment maintenance with economical benefit of enterprise and marketing situation of products, an optimal maintenance strategy will be got. It provides a new method for scientific and rational decisions of equipment maintenance.展开更多
The classical probabilistic reliability theory and fuzzy reliability theory cannot directly measure the uncertainty of structural reliability with uncertain variables, i.e., subjective random and fuzzy variables. In o...The classical probabilistic reliability theory and fuzzy reliability theory cannot directly measure the uncertainty of structural reliability with uncertain variables, i.e., subjective random and fuzzy variables. In order to simultaneously satisfy the duality of randomness and subadditivity of fuzziness in the reliability problem, a new quantification method for the reliability of structures is presented based on uncertainty theory, and an uncertainty-theory-based perspective of classical Cornell reliability index is explored. In this paper, by introducing the uncertainty theory, we adopt the uncertain measure to quantify the reliability of structures for the subjective probability or fuzzy variables, instead of probabilistic and possibilistic measures. We utilize uncertain variables to uniformly represent the subjective random and fuzzy parameters, based on which we derive solutions to analyze the uncertainty reliability of structures with uncertainty distributions. Moreover, we propose the Cornell uncertainty reliability index based on the uncertain expected value and variance.Experimental results on three numerical applications demonstrate the validity of the proposed method.展开更多
文摘This paper presents and analyses the internal and external efficiencies of equipment maintenance, and presents that the objective of maintenance is the maximum external efficiency. It defines generalized reliability degree of equipment and deduces the correspondent calculating method. It overcomes the defect that traditional calculating method of reliability degree has, which only considers the factor of time not function, therefore we establish a market decision model of equipment maintenance based on it. This model can determine the marginal efficiency of maintenance investment and critical value of generalized reliability degree when it reaches break-even point. After combining the equipment maintenance with economical benefit of enterprise and marketing situation of products, an optimal maintenance strategy will be got. It provides a new method for scientific and rational decisions of equipment maintenance.
基金co-supported by the National Natural Science Foundation of China (Nos. 51675026 and 71671009)the National Basic Research Program of China (No. 2013CB733002)
文摘The classical probabilistic reliability theory and fuzzy reliability theory cannot directly measure the uncertainty of structural reliability with uncertain variables, i.e., subjective random and fuzzy variables. In order to simultaneously satisfy the duality of randomness and subadditivity of fuzziness in the reliability problem, a new quantification method for the reliability of structures is presented based on uncertainty theory, and an uncertainty-theory-based perspective of classical Cornell reliability index is explored. In this paper, by introducing the uncertainty theory, we adopt the uncertain measure to quantify the reliability of structures for the subjective probability or fuzzy variables, instead of probabilistic and possibilistic measures. We utilize uncertain variables to uniformly represent the subjective random and fuzzy parameters, based on which we derive solutions to analyze the uncertainty reliability of structures with uncertainty distributions. Moreover, we propose the Cornell uncertainty reliability index based on the uncertain expected value and variance.Experimental results on three numerical applications demonstrate the validity of the proposed method.
