Since the traditional Miner rule ignores the influence of the load sequence on the fatigue life, the fuzzy rules are used to analyze the fuzziness of the fatigue damage caused by the stress nearby the fatigue limit un...Since the traditional Miner rule ignores the influence of the load sequence on the fatigue life, the fuzzy rules are used to analyze the fuzziness of the fatigue damage caused by the stress nearby the fatigue limit under different load sequences. The improved fuzzy Miner rule can reflect the influence of the load sequence on the fatigue life. Results of the example show that the prediction error can be reduced from 61.6% to 21.7%.展开更多
The calculation of fatigue stress ranges due to random waves and ice loads on offshore structures is discussed, and the corresponding accumulative fatigue damages of the structural members are evaluated. To evaluate t...The calculation of fatigue stress ranges due to random waves and ice loads on offshore structures is discussed, and the corresponding accumulative fatigue damages of the structural members are evaluated. To evaluate the fatigue damage to the structures more accurately, the Miner rule is modified considering the fuzziness of the concerned parameters, and a new model for fuzzy fatigue reliability analysis of offshore structures members is developed. Furthermore, an assessment method for predicting the dynamics of the fuzzy fatigue reliability of structural members is provided.展开更多
Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic load...Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.展开更多
First of all, the concept of γ_p_S a_S m_N (confidence level_reliability_stress amplitude_stress mean_fatigue life) surface is presented. Then the formulas of p_S a_S m_N surface and γ_p_S a_S m_N ...First of all, the concept of γ_p_S a_S m_N (confidence level_reliability_stress amplitude_stress mean_fatigue life) surface is presented. Then the formulas of p_S a_S m_N surface and γ_p_S a_S m_N surface are derived. In addition, fatigue strength distribution function and two_dimensional reliability Miner rule are obtained. At last, an example is given.展开更多
基金the National Natural Science Foundation of China(60472118)~~
文摘Since the traditional Miner rule ignores the influence of the load sequence on the fatigue life, the fuzzy rules are used to analyze the fuzziness of the fatigue damage caused by the stress nearby the fatigue limit under different load sequences. The improved fuzzy Miner rule can reflect the influence of the load sequence on the fatigue life. Results of the example show that the prediction error can be reduced from 61.6% to 21.7%.
文摘The calculation of fatigue stress ranges due to random waves and ice loads on offshore structures is discussed, and the corresponding accumulative fatigue damages of the structural members are evaluated. To evaluate the fatigue damage to the structures more accurately, the Miner rule is modified considering the fuzziness of the concerned parameters, and a new model for fuzzy fatigue reliability analysis of offshore structures members is developed. Furthermore, an assessment method for predicting the dynamics of the fuzzy fatigue reliability of structural members is provided.
基金supported by the National Natural Science Foundation of China(No.10377007)
文摘Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.
文摘First of all, the concept of γ_p_S a_S m_N (confidence level_reliability_stress amplitude_stress mean_fatigue life) surface is presented. Then the formulas of p_S a_S m_N surface and γ_p_S a_S m_N surface are derived. In addition, fatigue strength distribution function and two_dimensional reliability Miner rule are obtained. At last, an example is given.
