3차원 피로균열 진전해석을 통한 면외거셋 용접이음의 피로수명 평가
Assessment of Fatigue Life of Out-Of-Plane Gusset Welded Joints using 3D Crack Propagation Analysis
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초록
대형 용접 구조물에 대한 피로설계 수명의 예측은 일반적으로 Palmgren Miner과 등가손상도 방법 또는 선형누적손상도 방법을 사용한다. 또한 용접 구조물에서 피로 균열이 발생되면 잔존 수명은 S-N 곡선과 선형 파괴역학에 기초하여 예측되고 있다. 본 연구에서는 면외거셋 용접이음의 3차원 피로균열 진전거동과 피로수명을 예측하기 위하여 피로 시험을 실시하였다. 면외거셋 용접이음의 3차원 피로균열진전 해석은 NX NASTRAN 및 FRANC3D를 이용하여 유한요소 해석을 실시하였다. 면외거셋 용접이음의 균열 형상비, 초기균열 크기 및 응력비에 미치는 영향을 검토하기 위하여 피로균열진전 해석을 실시하였다. 또한 초기균열크기, 균열 형상비와 응력비의 변화에 따른 3차원 피로균열진전 해석 결과와 피로시험결과를 비교하였다. 피로균열진전 해석결과, 피로균열 진전속도와 응력확대계수와의 관계에서 피로시험과 유사하게 나타남을 확인하였으며, 면외거셋 용접이음의 피로수명을 추정할 수 있음을 확인하였다.
Abstract
The estimation of the fatigue design life for large welded structures is usually performed using the liner cumulative damage method such as Palmgren-Miner rule or the equivalent damage method. When a fatigue crack is detected in a welded steel structure, the residual service life has to be estimated base on S-N curve method and liner elastic fracture mechanics. In this study, to examine the 3D fatigue crack behavior and estimate the fatigue life of out-of-plane gusset fillet welded joint, the fatigue tests were carried out on the model specimens. Investigations of three-dimensional fatigue crack propagation on gusset welded joint was used the finite element analysis of FEMAP with NX NASTRAN and FRANC3D. Fatigue crack growth analysis was carried out to demonstrate the effects of aspect ratio, initial crack length and stress ratio on out-of-plane gusset welded joints. In addition, the crack behaviors of fatigue tests were compared with those of the 3D crack propagation analysis in terms of changes in crack length and aspect ratio. From this analysis result, SIFs behaviors and crack propagation rate of gusset welded joint were shown to be similar fatigue test results and the fatigue life can also be predicted.
참고문헌 (20)
- "BS 7608, Guide to Fatigue Design and Assessment of Steel Structures", British Standard Institution, ~ (2014)
- Carter, B. J., "Three-Dimensional Simulation of Fretting Crack Nucleation and Growth", Engineering Fracture Mechanics, 96, pp.447~460 (2012)[DOI]
- Elber, W., "Fatigue Crack Closure under Cyclic Tension", Engineering Fracture Mechanics, 2, pp.37~45 (1970)[DOI]
- "FRANC3D Version 6.0"[URL]
- Holmstrand, T., "Fatigue Life Assessment of Improved Joints Welded with Alternative Welding Techniques", Engineering Failure Analysis, 42, pp.10~21 (2014)[DOI]
- "Japanese Industrial Standard (JIS) G3106, Rolled Steel for Welded Structure", ~ (2008)
- Japanese Society of Steel Construction (JSSC), "Fatigue Design Recommendations for Steel Structures" (2012), Gihodo
- Jeon, Y. C., "A Study on Fatigue Life Prediction of Welded Joints Through Fatigue Test and Crack Propagation Analysis", Journal of the Society of Naval Architects of Korea, 38(3), pp.93~106 (2001)
- 김현수, "파괴역학 기반 피로 수명 평가를 위한 피로 균열 진전 파라미터에 관한 연구", 대한용접접합학회지, 35(1), pp.61~67 (2017), 대한용접접합학회[DOI]
- Kim, I. T., "Fatigue Strength Improvement of Longitudinal Fillet Welded Out-of-Plane Gusset Joints using Air Blast Cleaning Treatment", International Journal of Fatigue, 48, pp.289~299 (2013)[DOI]
- Klensil, M., "Influence of Strength and Stress History on Growth and Stabilisation of Fatigue Cracks", Engineering Fracture Mechanics, 4, pp.77~92 (1972)[DOI]
- 이치승, "용접구조물의 피로수명예측을 위한 수치해석모델", 대한용접접합학회지, 27(6), pp.49~54 (2009), 대한용접접합학회
- Miki, C., "A Survey of Fatigue Cracking Experience in Steel Bridges, IIW, XII-1383-90" (1990)
- Mikkola, E., "Equivalent Crack Approach for Fatigue Life Assessment of Welded Joints", Engineering Fracture Mechanics, 149, pp.144~155 (2015)[DOI]
- Stress-Intensity Factor Equations for Cracks in Three-Dimensional Finite Bodies Subjected to Tension and Bending Loads, NASA Technical Memorandum 85793, "Newman, J. C.", NASA Langley Research Center, ~ (1984)
- Paris, P. C., "A Critical Analysis of Crack Propagation Laws", Journal of Basic Engineering, 85, pp.528~534 (1960)
- Poursaeidi, E., "Fatigue Crack Growth Simulation in a Generator Fan Blade", Engineering Failure Analysis, 16, pp.888~898 (2009)[DOI]
- Rozumek, D., "Analytical and Numerical Evaluation of Stress Intensity Factor along Crack Paths in the Cruciform Specimens under Out-of-Phase Cyclic Loading", Engineering Fracture Mechanics, 77, pp.1808~1821 (2010)[DOI]
- Song, W. K., "Strain Energy Density based Fatigue Cracking Assessment of Load-Carrying Cruciform Welded Joints", Theoretical and Applied Fracture Mechanics, 90, pp.142~153 (2017)[DOI]
- Yamada, K., "Fracture Mechanics Analysis of Fatigue Cracks Emanating form Toe of Fillet Weld", Journal of Japan Society of Civil Engineers, 292, pp.1~12 (1979)