Non-Destructive Plastic Deformation Estimation of Aluminum Plates Using GMR Sensor-Based Eddy-Current Measurement

Hyeong Gon Ko; Hyung Jin Lim

doi:10.22725/JSRP.2026.4.1.27

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2026 Vol.4, Issue 1 Preview Page Next Page

Research Article

Non-Destructive Plastic Deformation Estimation of Aluminum Plates Using GMR Sensor-Based Eddy-Current Measurement GMR 센서 기반 와전류 계측을 이용한 알루미늄 평판 구조물의 소성변형 비파괴 추정

30 June 2026. pp. 27-34

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Abstract

This study presents a non-destructive technique for localizing and quantifying plastic deformation in aluminum (Al6061-T6) using a Giant Magneto-Resistance (GMR) sensor-based eddy-current measurement. Localized plastic deformation in metallic structures can initiate fatigue cracks and lead to structural failure, making its accurate evaluation critical for structural safety. To overcome the low sensitivity of conventional pick-up coils in detecting small eddy-current-induced magnetic field changes, a GMR sensor was employed in their place. The theoretical relationship between the plastic deformation ratio and the relative change in eddy-current phase was derived as a first-order linear function. For experimental validation, Al6061-T6 specimens with plastic deformation ratios of 0 %, 1 %, 3 %, 5 %, and 10 % were fabricated through tensile testing. The experimental results successfully identified the deformation locations and confirmed the linear relationship with R2= 0.9864. The proposed technique was further validated through blind tests on 2 % and 7 % specimens, yielding absolute errors of 1.350 % and 0.742 %, respectively.

Keywords

eddy-current measurement

Giant Magneto-Resistance (GMR) sensor

non-destructive testing

plastic deformation estimation

Al6061-T6

본 연구에서는 GMR(Giant Magneto-Resistance) 센서 기반 와전류 계측을 이용하여 알루미늄(Al6061-T6) 시편의 국부 소성변형 위치와 정도를 비파괴적으로 추정하는 기법을 제안하였다. 국부 소성변형은 피로균열의 시작점이 되어 구조물의 급격한 파괴로 이어질 수 있으므로 정확한 추정은 구조 안전성 확보에 필수적이다. 기존 픽업 코일의 낮은 민감도를 극복하기 위해 GMR 센서를 적용하였으며, 소성변형률과 와전류 상대 위상 변화율의 관계를 1차 선형 함수로 이론적으로 유도하였다. 0 %, 1 %, 3 %, 5 %, 10 %의 소성변형률을 가진 Al6061-T6 시편을 인장시험을 통해 제작하여 실험 검증을 수행한 결과, 국부 소성변형의 위치를 성공적으로 식별하였으며 상대 위상 변화율과 소성변형률 사이에 = 0.9864의 높은 선형 관계가 도출되었다. 또한 2 % 및 7 % 소성변형률 시편에 대한 블라인드 테스트에서 각각 1.350 %와 0.742 %의 절대오차로 소성변형 정도를 추정할 수 있음을 확인하였다.

키워드

와전류

거대자기저항 센서

비파괴 검사

소성변형 추정

알루미늄

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Information

Publisher :Korean Institute of Bridge and Structural Engineers
Publisher(Ko) :한국교량및구조공학회
Journal Title :Journal of Structure Research and Practice
Journal Title(Ko) :한국교량및구조공학회 논문집
Volume : 4
No :1
Pages :27-34
Received Date : 2026-06-04
Revised Date : 2026-06-24
Accepted Date : 2026-07-02
DOI :https://doi.org/10.22725/JSRP.2026.4.1.27

Journal of Structure Research and Practice ISSN:3022-4241(Print) 3022-7267(Online) 한국교량및구조공학회 논문집

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