基于涡流原理PCCP断丝的无损检测方法研究

Study on eddy current principle-based nondestructive testing method for broken wire of PCCP

基于涡流原理,提出一种PCCP(预应力钢筒混凝土管)断丝的无损检测方法;即:将PCCP视为放大后的类似金属管道,预应力钢丝作为主体结构,检测时利用内含线圈的探头在管内形成涡流,涡流产生磁场反作用于探头磁场,引起探头内磁通量的变化。通过采集探头阻抗波动即可获取磁通量变化,分析阻抗波动过程就能够推测出PCCP预应力钢丝的损伤情况。通过电磁感应和等效电路建立关联方程,推导阻抗波动公式,并在阐述试验方法的基础之上,初步论证了该方法的可行性。

Based on the eddy current principle,a nondestructive testing method for the broken wire of PCCP（ pre-stressed concrete cylinder pipe） is put forward herein; i. e. regarding PCCP as a similar metal pipe after amplification and taking the prestressed wire as its main structure,the eddy current inside of the pipe is created by the probe that contains a coil during the testing,and then the eddy current generates a magnetic field and reacts on the magnetic field of the probe to cause the change of the magnetic flux inside of the probe. Through the collection of the impedance fluctuation of the probe,the change of the magnetic flux can be obtained,thus the damage of the pre-stressed wire for PCCP can be estimated by analyzing the process of the impedance fluctuation. Through electromagnetic induction and equivalent circuit,thecorrelatione quation is established for deriving the formula of impedance fluctuation. Furthermore,the feasibility of this method ispreliminarily demonstrated on the basis of the description of it.