基于钢筋低周疲劳的桥墩地震易损性分析

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.

Seismic Fragility Analysis of Bridge Piers Based on Low cycle Fatigue Life of Reinfrocing Steel

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.