7B04-T6铝合金腐蚀疲劳交替寿命预测模型

利用7B04-T6铝合金进行了预腐蚀试验和"腐蚀+疲劳+腐蚀+疲劳+……"交替模式作用下的腐蚀疲劳交替试验.试验结果表明:在腐蚀疲劳交替作用下,试验件寿命比相同腐蚀时间作用下的预腐蚀试验件寿命长.利用试验结果建立了基于损伤力学和非线性损伤累积理论的腐蚀疲劳交替寿命预测模型.提出了利用损伤指数描述腐蚀损伤和疲劳损伤在交替过程中的耦合关系,并分析了损伤指数变化对模型迟滞因子和模型预测精度的影响.通过模型分析,在腐蚀疲劳交替过程中,疲劳加载次数对寿命的影响大于腐蚀时间的影响,并且随着加载次数增加试验件的寿命也增加. 

Life prediction model of 7B04-T6 aluminum alloy under alternate action of corrosion and fatigue

The alternate test of corrosion and fatigue and pre-corrosion test were carried out on 7B04-T6 aluminum alloy. The test results showed that the life of alternate test in sequence of "corrosion+fatigue+corrosion+fatigue+……" was longer than pre-corrosion test under the same corrosion time. According to the test results, the life prediction model of alternate action corrosion and fatigue was built based on the theory of damage mechanics and nonlinear damage cumulative theory. The damage exponent described the relationship of corrosion damage and the fatigue damage of the alternate action of corrosion and fatigue. The effects of damage exponent on precision and hysteretic factor of the model were discussed. Fatigue cycles had more serious effect on the total life than the corrosion time in the progress of alternation action of corrosion and fatigue. The total life got longer with the increase of fatigue cycles.