基于连续介质损伤力学的坑蚀钢筋高周疲劳寿命与损伤分析

以实测HRB400钢筋的疲劳损伤模型参数为基础,结合加速锈蚀钢筋蚀坑形貌和疲劳试验结果,通过二次开发在Abaqus平台上实现了坑蚀钢筋高周疲劳寿命预测和损伤过程分析.结果表明:坑蚀钢筋高周疲劳寿命预测结果与试验值吻合较好;坑蚀钢筋蚀坑处存在应力集中,疲劳损伤主要集中在蚀坑底部附近,疲劳前期和中期损伤发展缓慢,疲劳后期疲劳损伤迅速累积;坑蚀钢筋弹性模量随循环加载次数的增加而降低;坑蚀钢筋蚀坑底部的应力在疲劳后期迅速降至较低值,并向周边转移,应力重新分布.

Numerical Analysis of High Cycle Fatigue Life and Damage of Pitted Corroded Steel Bar Based on Continuum Damage Mechanics

The fatigue damage model parameters of HRB400steel bar were obtained through testing. According to the pit morphology and fatigue test results of corrosion accelerated steel bars, the high cycle fatigue life prediction and damage process analysis of pitted corroded steel bars were realized through secondary development on the Abaqus platform. The results show that the fatigue life prediction results agree well with the experimental values. There is stress concentration at the pit, and the fatigue damage is concentrated near the bottom of the pit. The damage in the early and middle stages of fatigue develops slowly, and then accumulates rapidly at the end of fatigue life. The elastic modulus of the material decreases with cyclic loading. The stress at the bottom of the pit drops to a lower value rapidly at the late stage of fatigue life and shifts to the periphery, and stress redistribution occurs.