利用局部磁滞回线特性的无损检测新方法

Abstract

提出了一种利用局部磁滞回线特性的无损检测新方法。首先,研究了钢板内部缺陷对其动态磁导率分布的影响规律。其次,探讨了变励磁条件下局部磁滞回线的形成机理,并建立了动态磁导率与局部磁滞回线之间的关系模型。再次,根据所建立的关系模型,提出了一种利用局部磁滞回线特性实现对钢板缺陷进行无损检测的新方法,并给出检测系统的实现方案。最后,通过3d有限元法对实验模型进行仿真,并开展了一系列的物理实验进行了验证。结果表明,缺陷对钢板动态磁导率分布的影响显著,可利用局部磁滞回线特性来检测磁导率变化,从而达到检测内部缺陷,甚至背面缺陷的目的。所提新方法无需检测静态漏磁场磁感应强度,因此有效减小了磁化器体积。

A new nondestructive test method based on local hysteretic loop characteristics is proposed in this paper.First of all,the influence law of the steel plate internal defects on the dynamic permeability distribution is studied,and the formation mechanism of the local hysteretic loop under the variable magnetic excitation condition is discussed.Secondly,the relation model between the dynamic permeability and local hysteretic loop is established.Furthermore,according to the proposed relation model,a new nondestructive test method of steel plate defects based on the local hysteretic loop characteristics is proposed,and the implementation scheme of the test system is given.Finally,the 3D finite element method was used to simulate the experiment model and a series of physical experiments were carried out to verify the proposed method.The results show that the steel plate defects have significant influence on the dynamic permeability distribution; the local hysteretic loop characteristics can be used to detect the permeability variation,and achieve the goal of detecting the internal defects of the steel plate,even the defects on the back of the steel plate.The proposed new method does not require to test the static leakage magnetic field,which reduces the volume of the magnetizing apparatus effectively.