Theoretical Analysis and Numerical Simulation of the Feasibility of Inspecting Nonferromagnetic Conductors by an MFL Testing Apparatus. Issue 2 (2nd April 2016)

• Record Type: Journal Article
• Authors: Feng, Bo; Kang, Yihua; Sun, Yanhua
• Is Part Of: Research in nondestructive evaluation. Volume 27:Issue 2(2016)
• Page Start: 100
• Page End: 111
• Publication Date: 2016-04-02
• Subjects: Eddy current -- finite element method -- magnetic flux leakage (MFL) -- nondestructive testing (NDT) -- velocity effect; Nondestructive testing -- Periodicals; 620.112705
• DOI: 10.1080/09349847.2015.1061721
• Languages: English
• ISSNs: 0934-9847

Abstract

ABSTRACT: It has been widely accepted that the magnetic flux leakage (MFL) testing system can be applied only to the inspection of ferromagnetic materials. The possibility of using the MFL testing apparatus to inspect nonferromagnetic metals is discussed in this article. According to Faraday's law of induction, eddy current rises in the conductor passing through the MFL magnetizer. The perturbation of eddy current and its corresponding magnetic field caused by defects are theoretically analyzed. Then, the finite element method is carried out to verify the theoretical analyses and extract the perturbed magnetic field signals. Furthermore, the influences of specimen conductivity and moving velocity on the detection signal amplitude are also simulated. The results show that the nonferromagnetic conductors are possible to be inspected by the MFL apparatus, and higher conductivity or inspection speed will facilitate the inspection.