为获得腐蚀钢绞线的断裂失效概率模型,需要研究基于某种断裂准则的断裂抗力分布模型。首先提出了以塑性理论中的Mises应变作为断裂参量的腐蚀钢绞线的断裂准则,然后通过对14根氯盐腐蚀钢绞线试样的拉伸试验获得了46根断裂钢丝以及它们在拉断时的平均拉应力及断口处蚀坑的几何形状与尺寸,并采用ANSYS有限元软件模拟得到了每根钢丝的断裂抗力值;以此作为腐蚀钢绞线断裂抗力分布的数据样本,采用数理统计软件SPSS分析了其分布特征,结果表明.在0.05的显著性水平下,腐蚀钢绞线的断裂抗力不拒绝正态分布及对数正态分布,并得到了这两种分布模式下腐蚀钢绞线断裂抗力的分布模型(概率密度函数)。
Mises strain from plastic theory was put forward to be the fracture criterion of corroded steel strands. By tension tests of 14 corroded steel strands with chloride, 46 breaking wires were obtained with the mean tension stress and the geometric configuration of the pit. Based on the above, the fracture resistance of each breaking wire was simulated by the finite element software ANSYS. And the simulation results were addressed to analyse the characteristics of fracture resistance with SPSS software. It was found that at the significance level of 0.05, both normal distribution and logarithmic normal distribution were not refused for the fracture resistance distribution. Hence, the distribution models (percentage distribution function) were obtained under the two distribution modes.