不均匀锈蚀钢筋截面分布特征与拉伸数值模拟

Cross-Section Distribution Feature and Tensile Numerical Simulation of Non-Uniform Corroded Steel Bars

为研究锈蚀钢筋剩余截面积的分布规律,以及非均匀锈蚀对钢筋力学性能的影响,采用通电加速锈蚀试验获取锈蚀钢筋。通过3D扫描获取锈蚀钢筋的剩余截面积数据和3D实体模型,对剩余截面积进行统计分析,并基于3D扫描模型进行数值模拟。结果表明:剩余截面积沿纵向分布的不均匀性随锈蚀程度增加而显著增强;对平均截面锈蚀率在20.00%以下的钢筋,可采用正态分布模型对其剩余截面积概率分布进行拟合,对平均截面锈蚀率在20.00%以上的钢筋,其剩余截面积概率分布可选用Weibull分布模型;钢筋名义屈服强度、名义极限强度和名义极限应变均随平均截面锈蚀率的增大而降低;在钢筋截面锈损严重处出现应力集中现象,导致锈蚀钢筋力学性能退化。

To study the distribution of residual cross-sectional area of corroded steel bars and the effect of non-uniform corrosion on the mechanical properties of steel bars,the corroded steel bars are obtained by electric accelerated corrosion test.The residual cross sectional area data and 3D solid model of the corroded steel bars are obtained by 3D scanning,the residual cross sectional area is analyzed statistically,and numerical simulation is carried out base on 3D scanning model.The results show that the non uniformity of residual cross sectional area along the longitudinal direction increases significantly with the increase of corrosion degree.For steel bars with average cross sectional corrosion rate<20.00%,the normal distribution model can be used to fit the probability distribution of the residual cross sectional area,and for steel bars with average cross sectional corrosion rate>20.00%,Weibull distribution model can be used to fit the probability distribution of the residual cross sectional area.Nominal yield strength,nominal ultimate strength and nominal ultimate strain of steel bars decrease with the increase of average cross sectional corrosion rate.The stress concentration occurs at areas with severe rust damage,which leads to the degradation of mechanical properties of the corroded steel bars.