论文部分内容阅读
基于柔度法的纤维模型能更高效地计算钢筋混凝土柱的材料强非线性受力特征,但不考虑纵筋屈曲、疲劳损伤的钢筋本构模型仍将明显降低其受力后期的数值模拟精度。以8根钢筋混凝土柱抗震性能试验结果为基础,在OpenSees平台上采用可以考虑纵筋屈曲、疲劳损伤的钢筋本构模型以及柔度法纤维模型,对柱的滞回性能进行分析。分析结果表明,与小轴压比柱相比,纵筋屈曲对高轴压比柱峰值荷载之后的水平承载力退化影响更明显;对纵筋长径比小于3.0的柱,纵筋屈曲对非线性分析结果的影响可基本忽略;纵筋长径比为5.00~8.75且柱轴压比较小时,纵筋屈曲对分析结果有一定影响,但考虑疲劳损伤的计算结果能更好模拟柱软化段的水平承载力退化特征;柱轴压比较大且纵筋长径比为6.25~7.00时,考虑纵筋屈曲、疲劳损伤均会明显减小承载力退化的计算误差。同时考虑纵筋屈曲及疲劳损伤的分析结果能更好地反映柱的承载力退化特征。
The fiber model based on the flexibility method can calculate the strong non-linear force characteristics of reinforced concrete columns more efficiently. However, the constitutive model of reinforced concrete without longitudinal buckling and fatigue damage will still significantly reduce the numerical simulation accuracy . Based on the experimental results of the seismic behavior of eight reinforced concrete columns, the hysteretic behavior of the columns was analyzed on the OpenSees platform using a steel constitutive model considering the buckling and fatigue damage of longitudinal reinforcement and the fiber model of compliance method. The results show that, compared with the small axial compression column, the longitudinal reinforcement buckling has a more obvious effect on the horizontal bearing capacity degradation after the peak axial load is higher than that of the low axial compression ratio column. The effect of linear analysis results can be neglected. When the aspect ratio of longitudinal ribs is 5.00-8.75 and the axial compression ratio is small, longitudinal buckling has some influence on the analysis results. However, considering the fatigue damage calculation results, When the axial compression ratio is large and the aspect ratio of the longitudinal reinforcement is between 6.25 and 7.00, considering the longitudinal buckling and fatigue damage, the calculation error of the bearing capacity degradation will be obviously reduced. At the same time, the results of longitudinal buckling and fatigue damage analysis can better reflect the degradation characteristics of column bearing capacity.