Field surveying shows that the failure of the steam turbine's coupling is due to fatigue that is caused by compound stress. Fuzzy mathematics was applied to get the membership function of the fatigue strength rul...Field surveying shows that the failure of the steam turbine's coupling is due to fatigue that is caused by compound stress. Fuzzy mathematics was applied to get the membership function of the fatigue strength rule. A formula of fuzzy reliability of the coupling was derived and a theory of coupling's fuzzy reliability is set up. The calculating method of the fuzzy reliability is explained by an illustrative example.展开更多
Prediction of structural performance is complicated by many uncertainties of random or fuzzy character. This paper presented an initial investigation on reliability theory of structure involved with fuzziness. The mem...Prediction of structural performance is complicated by many uncertainties of random or fuzzy character. This paper presented an initial investigation on reliability theory of structure involved with fuzziness. The membership function of structural safety was established. The calculation methods of fuzzy reliability of structure were also presented, and as an example, the fuzzy reliability of simply supported beam was calculated.展开更多
In hydraulic turbine engineering,turbine blade vibration reliability assessment is of great significance. Based on the interval mathematical theory, the variables existing in hydraulic turbine blade are described as i...In hydraulic turbine engineering,turbine blade vibration reliability assessment is of great significance. Based on the interval mathematical theory, the variables existing in hydraulic turbine blade are described as interval variables. Considering the fuzzy failure criterion of turbine blade distancing from resonance and vibration fatigue stress,fuzzy possibilistic reliability is expressed and analyzed qualitatively taking normal bathtub function as the membership function of blade resonance failure and deflection major type function as the membership function of the intensity failure. As a result,hydraulic turbine blade vibration reliability is analyzed based on the fuzziness of variables and failure criterion. A safer working environment is provided under possibility context by comparing with the qualitative conclusions in the past literature.展开更多
文摘Field surveying shows that the failure of the steam turbine's coupling is due to fatigue that is caused by compound stress. Fuzzy mathematics was applied to get the membership function of the fatigue strength rule. A formula of fuzzy reliability of the coupling was derived and a theory of coupling's fuzzy reliability is set up. The calculating method of the fuzzy reliability is explained by an illustrative example.
文摘Prediction of structural performance is complicated by many uncertainties of random or fuzzy character. This paper presented an initial investigation on reliability theory of structure involved with fuzziness. The membership function of structural safety was established. The calculation methods of fuzzy reliability of structure were also presented, and as an example, the fuzzy reliability of simply supported beam was calculated.
基金National Natural Science Foundation of China(No.51379179)the Open Research Subject of Key Laboratory of Fluld and Pow er M achinery,Ministry of Education,China(No.szjj2014-046)Key Scientific Research Fund Project of Xihua University,China(No.Z1320406)
文摘In hydraulic turbine engineering,turbine blade vibration reliability assessment is of great significance. Based on the interval mathematical theory, the variables existing in hydraulic turbine blade are described as interval variables. Considering the fuzzy failure criterion of turbine blade distancing from resonance and vibration fatigue stress,fuzzy possibilistic reliability is expressed and analyzed qualitatively taking normal bathtub function as the membership function of blade resonance failure and deflection major type function as the membership function of the intensity failure. As a result,hydraulic turbine blade vibration reliability is analyzed based on the fuzziness of variables and failure criterion. A safer working environment is provided under possibility context by comparing with the qualitative conclusions in the past literature.
