钢管混凝土加固锈蚀损伤柱偏压性能数值计算分析

Numerical calculation and analysis of performance of corroded amaged columns strengthened with concrete-filled steel tubes under eccentric load

采用电化学加速锈蚀方法获取20个不同锈蚀损伤柱,并利用钢管混凝土加固法对其中13个锈蚀损伤柱进行加固。通过偏心受压试验,获得了锈蚀柱和加固柱的破坏形态、承载力和荷载-挠度变形曲线。在试验研究基础上,建立了钢管混凝土加固锈蚀钢筋混凝土(reinforced concrete,RC)柱偏压性能有限元模型,并将有限元计算结果与试验结果进行了对比分析。结果表明,所建的有限元模型能够准确模拟出加固柱的破坏形态,加固柱承载力试验值与计算值之比的均值为0.956、标准差为0.031、变异系数为0.032,所建有限元模型可以较为准确地计算钢管混凝土加固锈蚀RC柱的偏压性能。利用该模型对加载过程中加固柱各部分的应力分布、发展情况、偏心距的影响以及钢管对受压弯曲内侧和外侧混凝土的约束作用进行了详细分析,进一步揭示了加固柱的受力机理。

The electrochemical accelerated corrosion method is used to obtain 20 RC columns with different corrosion degrees, and 13 of them are strengthened with concrete-filled steel tubes. Through the eccentric compression test, the failure mode, bearing capacity and load-deflection curve of the corroded and strengthened columns are obtained.On the basis of experimental research,finite element(FE) model of the bias performance of RC column reinforced by concrete-filled steel tube(CFST) is established, and the finite element calculation results are compared with the experimental results. It is found that the FE model can accurately simulate the failure form of the reinforced column.In terms of the bearing capacity of reinforced RC columns,the mean ratio of the experimental value to the calculated value is 0.956,the standard deviation is 0.031,and the coefficient of variation is 0.032, indicating that the built FE model can accurately calculate the bias performance of strengthened columns. Based on the model, the stress distribution and development of each part of the composite columns during the loading process and the restraint effect of the steel tubes on the compression bending inside and outside concrete are analyzed in detail,and the mechanisms of the strengthened columns are further revealed.