基于钢筋低周疲劳的桥墩地震易损性分析

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

摘要:

基于CoffinManson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CoffinManson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.

Abstract:

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.