基于刚度退化和滞回耗能的圆钢管混凝土柱损伤模型

Stiffness degradation and hysteretic energy dissipation based damage model of concrete-filled circular steel tube columns

由于现有的钢管混凝土柱损伤模型中存在损伤计算不收敛、缺乏对构件不同性能水平量化分析等问题,本文结合64个圆钢管混凝土试件,以试件钢管破坏现象、承载力变化和侧移等指标,建立了钢管混凝土柱试件损坏程度、破坏现象与损伤指数对应关系,并提出基于刚度退化与滞回耗能指标的S-E双参数损伤模型(S与E分别为stiffness和energy的缩写),最后通过低周反复试验试件、低周疲劳试验试件以及一榀框架结构试验试件验证了S—E损伤模型的合理性。结果表明,本文提出的损伤模型计算曲线与试件实际损伤曲线吻合良好,能合理评估构件不同阶段的损坏程度,为进一步研究地震作用下钢管混凝土柱的损伤评估提供参考。

As the calculation of concrete-filled circular steel tube（ CFST） damage models can＇t match the real damage states and there is no performance levels for CFST members,in the paper experimental data of 64 CFST columns were extensively studied,and the relationship between the damage conditions of the CFST columns and the damage indexes was built by considering the failure of the steel-tube,bearing capacity and lateral drift of the columns,then a new damage model,S-E damage model,which was based on stiffness degradation and hysteretic energy dissipation,was proposed. Finally,the new S-E damage model was verified by experiments of some low cyclic,low-cycle fatigue specimens and a CFST frame structure. Results show that the damage index curve calculated by using the S-E damage model was in good agreement with the practical damage curve of the specimens,and the damage conditions corresponding to different stages could be assessed reasonably,which provided references for the further study of damage assessment of CFST columns under seismic excitations.