基于蒙特卡罗法的不均匀锈蚀钢筋力学性能评估

Evaluation of mechanical properties of non-uniform corroded rebars based on Monte Carlo method

本文基于符合锈蚀钢筋形貌特征的截面积概率分布函数,并考虑锈坑处相邻截面的相关性,建立了不均匀锈蚀钢筋的三维有限元模型,通过蒙特卡罗模拟批量开展数值拉伸试验,定量研究不同锈蚀率下钢筋力学性能的退化情况。与已有的试验结论对比显示,该方法能较好地估计锈蚀钢筋的力学性能,尤其是钢筋的变形能力。本文研究了锈蚀钢筋不同本构和标距长度对力学性能的影响,结果表明:钢筋的强屈比是影响其变形能力的主要因素,不同的标距长度将会显著影响锈蚀钢筋极限应变的计算结果。

To enable a reliable analysis of the residual behavior of corroded rebars,a computationallyefficient method capable of considering the corrosion morphology characteristics was proposed by the probability distribution function of the cross-section area.The degraded mechanical properties of rebars under different corrosion rates were quantitatively studied based on the combination of Monte Carlo method and numerical tensile tests of corroded rebars.This method can accurately estimate the mechanical properties of corroded rebars verified with previous test results,especially for the deformation capacity.The effects of constitutive laws and gauge lengths were analyzed respectively.The results show that the strength yield ratio of rebars is the dominant issue governing deformation capacity after being corroded,and different gauge lengths are responsible for the different calculation results of the ultimate strain of corroded rebars.