中文摘要：

基于Coffin—Manson钢筋疲劳损伤模型，采用非线性纤维梁柱单元，对纵筋采用HRB335和HRB500E的圆柱形桥墩拟静力试验进行数值模拟，研究拟静力作用下低周疲劳对钢筋和构件承载力退化的影响．为了进一步研究钢筋低周疲劳对试件累积损伤的影响，将Takemura和Kunnath提出的两组不同加载模式下的拟静力试验进行数值模拟．结果表明：基于Coffin-Manson模型，采用纤维单元，在材料层面上考虑钢筋的低周疲劳，可以较好地模拟试件在不同加载模式下的累积损伤和承载力退化．

英文摘要：

A nonlinear fiber beam-column element was used to simulate quasi-static tests of circular concrete bridge piers reinforced with HRB335 and HRB500E longitudinal bars based on Coffin-Manson low-cycle fatigue damage model for reinforcing steel. The effects of low-cycle fatigue damage on the strength degradation of reinforcing steel and reinforced concrete specimens were studied. In order to further verify the effect of low-cycle fatigue of reinforcing steel on the cumulative damage of reinforced concrete specimens, two quasi-static tests proposed by Takemura and Kunnath with different loading modes were conducted. The results indicate that, the fiber beam-column element could simulate the cumulative damage and strength degradation of reinforced concrete columns under different loading modes when considering the low-cycle fatigue of reinforcing steel on material level by using Coffin-Manson model.