基于损伤演化律的腐蚀疲劳寿命预测方法及应用

摘要

In view of the shortage of analytical and test methods for corrosion fatigue life prediction, an engineering applicable life prediction method based on damage evolution theory is proposed.Comprehensively considering the influences of the stress corrosion damage controlled by mean stress and fatigue damage controlled by stress amplitude on corrosion fatigue life, a non-linear damage index is introduced to establish the nonlinear accumulation evolution law of corrosion fatigue damage.The basic ideas and the main implementation details of the proposed method are presented.The method is applied to analyze the corrosion fatigue behavior of super-strength sucker rod steel FG20 (16Mn2SiCrMoVTiA) and LY12CZ aluminum alloy in the corrosive liquid, and the variations of damage parameters with materials and fatigue loads are obtained.%针对腐蚀疲劳寿命预测解析与试验方法的不足,提出一种基于损伤演化的腐蚀疲劳寿命工程预测方法.综合考虑最大应力控制的应力腐蚀损伤与应力幅值主导的疲劳损伤对腐蚀疲劳寿命的影响,引入非线性累积损伤指数,构建腐蚀疲劳损伤演化律模型.阐述了所提方法的基本思想和主要实现方法,并应用上述方法对超高强度抽油杆FG20(16Mn2SiCrMoVTiA)钢和LY12CZ铝合金的腐蚀疲劳问题进行了研究,分析了不同材料腐蚀疲劳模型损伤参数的变化.