基于动态压磁的锈蚀钢筋疲劳特性的试验研究

Experimental research on fatigue properties of corroded steel bars based on dynamic piezomagnetism

为了解决传统锈蚀钢筋疲劳性能研究中检测方法有限、评估疲劳损伤困难等不足,研究一种新型的基于压磁效应的无损检测方法.通过对28根不同锈蚀率下的加速锈蚀钢筋进行轴向拉伸疲劳试验,研究疲劳损伤过程中压磁信号的演变规律,挖掘压磁信号与钢筋锈蚀程度之间的关系.试验结果表明:压磁信号对钢筋疲劳损伤有较好的敏感性,结合磁感强度值时变曲线、磁感强度-应变滞回曲线等压磁信息,能够反映钢筋的疲劳损伤累积过程、锈蚀程度及塑性状态.试验成果为结构的损伤评估和寿命预测提供了一个有效的无损检测方法.

A new nondestructive method based on piezomagnetic effect was investigated in order to solve the problems of traditional methods,such as there are few approaches and difficulties of damage assessment when studying the fatigue performance of corroded steel bars.Axial tensile fatigue tests of 26corrosion-accelerated steel bars were carried out to analyze the evolution of magnetic signals in the process of fatigue.The relationship between magnetic signal and corrosion degree of steel was explored.Testing results demonstrate that piezomagnetic signal is very sensitive to steel fatigue damage.The accumulation of fatigue damage,corrosion degree and plastic state can be reflected effectively using the information of the piezomagnetic time-varying curve and the piezomagnetic hysteretic loop.The achievements provide an effective non-destructive testing method for the damage assessment and fatigue life prediction of structure.