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한국강구조학회 학술지영문홈페이지
[ Article ]
Journal of Korean Society of Steel Construction - Vol. 36, No. 6, pp.451-459
ISSN: 1226-363X (Print) 2287-4054 (Online)
Print publication date 27 Dec 2024
Received 21 Oct 2024 Revised 06 Dec 2024 Accepted 07 Dec 2024
DOI: https://doi.org/10.7781/kjoss.2024.36.6.451

장대레일 테르밋 용접부의 초기균열 크기 분포 추정

이재연1 ; 박연철2 ; 김지현3, * ; 권준혁4
1석사과정, 인하대학교, 토목공학과
2조교수, 인하대학교, 사회인프라공학과
3선임연구원, 한국철도기술연구원
4주임, 한국철도공사
Estimating the Initial Crack Size Distribution of Thermite Welds Joint in Continuous Welded Rail
Lee, Jae Yeon1 ; Park, Yeun Chul2 ; Kim, Ji Hyeon3, * ; Kwon, Jun Hyeok4
1Graduate Student, Dept. of Civil Engineering, Inha University, Incheon, 22212, Korea
2Assistant Professor, Dept. of Civil Engineering, Inha University, Incheon, 22212, Korea
3Senior Researcher, Railroad Structure Research Department, Korea Railroad Research Institute, Geonggi-do, 16105, Korea
4Chief, Dept. of Civil Engineering, Korea Railroad Corporation, Jecheon, 27195, Korea

Correspondence to: *Tel. +82-31-460-5254 Fax. +82-31-460-5159 E-mail. jhkim06@krri.re.kr

Copyright © 2024 by Korean Society of Steel Construction

초록

장대레일의 테르밋 용접부는 현장에서 시공되기 때문에 다른 용접 방식에 비해 용접 결함이 발생할 가능성이 높다. 따라서 반복적인 하중으로 인해 용접부에 발생하는 균열의 크기에 따라 피로수명이 결정된다. 본 연구에서는 레일 초기 균열의 크기 분포를 추정하기 위해 국내외에서 수행된 기존 피로 실험 결과를 활용하였고, Paris’ law를 사용하였다. 초기 균열 크기 분포를 추정하기 위해 파괴면을 확인하기 쉬운 시편을 이용하여 피로 수명에 영향을 미치는 주요 요인인 파괴 인성 및 재료 상수를 분석하였으며, 균열성장해석을 통해 초기균열 깊이의 평균 및 표준편차를 각각 0.6 mm와 0.2 mm로 추정하였다.

Abstract

Thermite weld joint in continuous welded rail is constructed on-site and are more likely to have welding defects compared to other welding methods. Therefore, fatigue life is determined by the size of cracks that occur in the weld zone due to repeated loading. In this study, the results of existing fatigue experiments conducted were used to estimate the size of initial cracks in the rail, and the Paris’ Law was used as the estimation equation. To estimate the initial crack size, fracture toughness and material constants, which are major factors affecting fatigue life, were analyzed using specimens whose fracture surface was easy to confirm through fatigue experiments. The mean and standard distribution of the initial crack depth were estimated to be respectively 0.6 mm and 0.2 mm through crack growth analysis.

Keywords:

Fatigue crack, Thermite weld, Continuous welded rail, LEFM, S-N curve, Initial crack size

키워드:

피로균열, 테르밋 용접, 장대레일, 선형탄성파괴역학, S-N 선도, 초기균열 크기

Acknowledgments

본 연구는 한국철도기술연구원 기본사업(장대레일 성능기반 유지관리 체계 구축, PK2403A1)의 연구비 지원으로 수행되었습니다. 이에 감사드립니다.

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