• 한국산업융합학회 논문집
• /
• 제25권5호
• /
• pp.827-833
• /
• 2022

In this study, the prediction of the bending angle for the 350 A bellows-type expansion joints and the structural stability according to the load were determined. The stability of the 2km piping system was predicted by applying the allowable bending angle of the expansion pipe joint obtained from the analysis. The maximum bending angle was calculated through bending analysis of the bellows-type expansion joints, and the maximum bending angle by numerical calculation was about 1.8°, and the maximum bending angle of the bellows obtained by comparing the allowable strength of the material was about 0. 22°. This angle was very stable compared to the allowable bending angle (3°) of the expansion pipe joint regulation. By applying the maximum bending angle, the allowable maximum deflection of the 2 km pipe was about 3.8 m. When the seismic load was considered using regression analysis, the maximum deflection of the 2km pipe was about 142.3mm, and it was confirmed that the bellows-type expansion joints and the deflection were stable compared to the allowable maximum deflection of the pipe system. These research results are expected to present design and analysis guidelines for the construction of piping and the development of bellows systems, and to be used as basic data for systematic research.

• 오토저널
• /
• 제9권4호
• /
• pp.61-68
• /
• 1987

The Bellows Joint which was used as a absorber or safety equipment to prevent the deformation or fracture of a structure, have been analyzed by the F.E.M using axi-symmetric conical frustum element. Using the F.E.M the general behavior of Bellows Joint corrugation can be investigated easily, and the stability of the analysis be guaranteed. In annular type corrugation, the F.E.M results were agreed with those of other theoretical analyses, but in the U type corrugation, the F.E.M results were more acceptable than those of others.

• 대한기계학회논문집A
• /
• 제39권4호
• /
• pp.429-435
• /
• 2015

벨로우즈는 줄-톰슨 소형 극저온 냉각기에서 온도조절장치로 사용하는 중요한 부품이다. 벨로우즈는 매우 얇은 쉘로 제작되었으며 내부는 질소기체로 충전되어 있다. 또한 재료는 니켈-코발트 합금이며 이 재질은 $300^{\circ}C$에서 극저온까지 탄성계수와 강도가 변하지 않는 금속이다. 벨로우즈 내부의 기체는 온도가 바뀌면 기체의 압력과 부피가 변하고 결과적으로 벨로우즈가 길이 방향으로 수축 또는 팽창한다. 이 현상을 해석하기 위하여 주어진 온도에서 기체의 상태방정식이 만족될 때까지 수정된 압력하에서 벨로우즈의 변형과 변형된 내부 체적을 반복적으로 계산하였다. 현 연구에서 기체의 온도-부피-압력 상태를 정의하는 식으로 MBWR 상태 방정식이 채택되었다. 제안한 해석 방법론의 타당성을 증명하기 위하여 실험을 수행하였고 비교결과 수치 해는 실험값과 잘 일치하였다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제40권7호
• /
• pp.587-592
• /
• 2016

LNG 선박용 벨로우즈는 극한의 환경에서 지속적인 진동 그리고 큰 온도변화에 따른 수축과 팽창을 견뎌내야 하는 피로수명과 해수환경에서의 내식성을 가져야 한다. 이러한 특성을 갖기 위해서는 저온에서의 인성이 강하고 내부식성이 강한 재료를 사용하여 최적화된 성형조건을 유지하는 것이 매우 중요하다. 이를 위해서는 벨로우즈의 최적화된 설계 조건과 성형방법이 뒷받침되어야 한다. 본 연구에서는 기계적 강성과 신뢰성이 높은 극저온용 벨로우즈를 개발하기 위하여 유한요소 해석을 통해 벨로우즈를 설계하였다. 또한 두 가지의 성형방법을 통해 설계된 벨로우즈를 제작하여 최적화된 성형조건을 도출하고자 하였다. 기계식 성형방법과 하이드로포밍 방법을 통해 벨로우즈를 성형하고 성형방법에 따른 벨로우즈의 기계적 특성을 비교하기 위하여 성형부의 높이, 두께 및 비커스 경도 값을 측정하였다. 이를 통해 기계식 성형방법으로 제작된 벨로우즈의 경도 값이 하이드로포밍 제작 벨로우즈보다 더 높은 것을 확인하였다.

• 대한기계학회논문집A
• /
• 제35권9호
• /
• pp.1007-1013
• /
• 2011

상용차용 다층관 벨로우즈는 우수한 유연성과 내구성이 요구되므로 단층으로 제조되는 승용차용 벨로우즈와는 다르게 다층의 형태로 제작된다. 단층 벨로우즈의 유한요소해석과 최적화에 대한 연구는 활발히 진행되고 있으나, 층과 층사이에 갭이 존재하는 다층형 벨로우즈의 유한요소해석과 최적화 연구는 미진하다. 따라서 본 연구에서는 해석의 신뢰성 향상을 위해 다층형 벨로우즈에 적합한 유한요소 모델을 제시하였으며, 다층관 벨로우즈의 형상 최적화를 위해 실험계획법과 D-Optimal 방법에 기반을 둔 순차적 실험계획에 의한 크리깅 메타모델을 적용하였다.

• 동력기계공학회지
• /
• 제12권2호
• /
• pp.29-34
• /
• 2008

Bellows is widely used in many industrial fields as it provides a relatively simple means of absorbing mechanical shock, vibration and thermal deformation with flexibility. In this study, the inherent dynamic characteristics of curved bellows are numerically studied according to the variation of angle, curvature and crest density, etc. For these numerical studies, a parametric finite element modelling program of curved bellows is constructed using ANSYS APDL. The validity of numerical results obtained from ANSYS software is experimentally verified using the test model made by RP machine SLA 5000.

• 한국레이저가공학회지
• /
• 제15권1호
• /
• pp.10-14
• /
• 2012

Pulse laser welding was performed on C22 metal bellows. The results can be summarized as follows: Laser welded metal bellows had less thermal distortion, narrow HAZ, high aspect ratio in comparison with other welding processes like TIG, Plasma welding. Laser welded bellows has higher tensile strengths than that C22 base metal. The value of hardness in laser weld metal was measured 100-120 Hv, it was decreased compared to the base metal. It is reasoned that due to the annealed by heat input during the laser welding.

• 복합신소재구조학회 논문집
• /
• 제6권4호
• /
• pp.38-43
• /
• 2015

This study performed a finite element stress analysis of pipe system connected by bellows based on APDL(ANSYS Parametric Design Language) customizing. The effects of different shapes of developed pipes for various parameters are studied using the finite element commercial package for this study. The structural behavior of complex pipe structures with bellows was also investigated to study the interactions between bellows and other parts. Based on the ANSYS APDL, the effect of initial axial and lateral displacements, and internal temperature and pressure on the Von Mises stress distribution is also analyzed.

• 한국공작기계학회논문집
• /
• 제13권6호
• /
• pp.102-106
• /
• 2004

The purpose of the study is to perform structual analysis of 9 type bellows for automotive. The bellows joint which was used as a absorber or safety equipment to prevent the deformation or fracture of a structure, has been analyzed by the FEM modeling using axi-symmetric conical frustum element. Using FEM the general behavior of bellows analysis can be investigate easily, as well as the stability of the analysis can be guarantee. The results of finite element structual analysis and actual result gave a good agreement.

• 동력기계공학회지
• /
• 제5권4호
• /
• pp.31-37
• /
• 2001

Pressure propagation and attenuation characteristics in a hydraulic pipeline with a bellows type accumulator was investigated by theoretical analyses and experiments. In the first stage of the study, equations to evaluate the amount of oil volume charged into the bellows together with nitrogen gas were proposed. In the next stage, the authors suggested a mathematical model based on transfer matrix method to describe the dynamic characteristics of the pipe element with a metal bellows type accumulator. Through comparisons and considerations of the experimental and the numerical data shown in frequency domain, the validity of the mathematical model was confirmed.