【摘要】 试验测定了铝合金切口件在变幅块谱下于3.5％NaCl溶液中的腐蚀疲劳裂纹起始(CFCI)寿命。结果表明,变幅载荷谱中的大超载会显著延长CFCI寿命,并且超载方式和加载顺序具有明显的影响。根据反映大小载荷交互作用和腐蚀效应的超载CFCI寿命曲线,探讨了应用Miner累积损伤定则建立变幅载荷下切口件CFCI寿命估算模型的可行性,并应用平均秩对变幅块谱下CFCI寿命的分布进行了统计分析。讨论了变幅载荷谱下铝合金切口件CFCI的腐蚀效应。更多还原

【Abstract】 Corrosion fatigue crack initiation(CFCI) life of LY12CZ aluminum alloy notched specimens in 3.5% NaCl solution under variable amplitude loading block spectra was investigated experimentally. It was shown that overloading in the spectrum made the CFCI life longer considerably, and the loading sequence and the overloading type had a significant effect. So the overloading effect must be considered in the prediction of the CFCI life under variable amplitude loading. According to the CFCI life curves that revealed the overloading and corrosion effect, a study was made on applying Miner’s accumulative damage rule to predict CFCI life under variable amplitude loading. A model was established and was thereafter used to predict the CFCI life under the selected spectra. The predicting results showed good agreement with the testing. The distribution of the CFCI life under one spectrum was determined by using ranking methods. Corrosion effect on CFCI under variable amplitude loading was also discussed.更多还原