• 한국태양에너지학회 논문집
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• 제36권3호
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• pp.25-31
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• 2016

Gaskets are usually used for the sealing of flange joints. The joint is usually composed of two flanges, a ring gasket and clamping bolts. The metal ring gasket is suitable for pipe flanges, pumps and valve joints in high temperature and high pressure environments. A very high surface stress is developed between a ring type joint gasket and the flange groove when the ring type joint is bolted up in a flange. The dimensions of flanges and ring joint gaskets for the pipe sizes that are in common use are specified in the ANSI codes. However, sometimes it is necessary to make a new design for the flange joint which is not specified in the codes, as the equipment is getting larger and larger in size. This paper presents the contact behavior of Class 600 ring joint gaskets with oval and octagonal cross sections. Five different sizes of gaskets are employed in the analysis, and one of them is newly designed on the basis of analysis results obtained from existing models. Three load steps are used to find the stress, stain and contact pressure etc., and to compare the contact characteristics among the models due to the bolt clamping force and the working surface pressure. ANSYS Workbench version15 is used to conduct the finite element analysis.

• 한국기계가공학회지
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• 제21권1호
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• pp.66-72
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• 2022

The Mooney-Rivlin second order optimal strain energy function derived through uniaxial tensile test and analysis was applied to a gasket to confirm the internal stress and surface pressure generated during compression. The Taguchi method, a statistical technique, was used to design the optimum shape of the gasket, and through characteristic evaluation, the optimum shape of the gasket was obtained when the reference plane (T: 0.15 mm), contact surface (W: 1.00 mm), and curvature (R: 0.30 mm) were used. It was determined that the optimum shape yields a von Mises stress of 4.83 MPa, and the contact pressure stress is 20.14 MPa, which satisfies breakage and sealing requirements. In the future, we plan to manufacture a jig that can measure surface pressure to conduct comparative verification studies between the test results and analysis results.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.226-226
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• 2016

PHOLED devices which have the structure of ITO/HAT-CN(5nm)/NPB(50nm)/EML(30nm)/TPBi(10nm)/Alq3(20nm)/LiF(0.8nm)/Al(100nm) are fabricated to investigate the green emission profile in EML by using a gasket doping method. CBP and Ir(ppy)3 (2% wt) are co-deposited homogeneously as a background material of EML for green PHOLED, then a 5nm thickness of additionally doped layer by Ir(btp)2 (8% wt) is formed as a profiler of the green emission. The total thickness of the EML is maintained at 30nm while the distance of the profiler from the HTL/EML interface side (x) is changed in 5nm steps from 0nm to 25nm. As shown in Fig. 1, the green (513nm) peak from Ir(ppy)3 is not observed when Ir(btp)2 is also doped homogeneously because Ir(ppy)3 works as an gasket dopant of the Ir(btp)2 :CBP system. Therefore, in this experment, Ir(btp)2 can be used as a profiler of the green emission in CBP:Ir(ppy)3 system. The emission spectra from the PHOLED devices with different x are shown in Fig. 2. In this gasket doping system, stronger red peak means more energy transfer from green to red dopant or higher exciton density by green dopant. To find the green emission profile, the external quantum efficiency (EQE) at 3mA/cm2 for red peaks are calculated. More green light emission at near EML/HBL interface than that of HTL/EML is observed (insert of Fig. 2). This means that the higher exciton density at near EML/HBL interface in homogeneously doped CBP with Ir(ppy)3. As shown in Fig. 3, excitons can be quenched easily to HTL(NPB) because the T1 level of HTL(2.5eV) is relatively lower than that of EML(2.6eV). On the other hand, the T1 level of HBL(2.7eV) is higher than that of EML.

• 한국터널지하공간학회 논문집
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• 제5권4호
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• pp.361-370
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• 2003

본 논문에서는 쉴드TBM터널의 세그먼트 연결부 방수재로 기장 많이 사용되는 수팽창성 지수재와 가스켓의 방수성능을 실험을 통하여 평가하였다. 방수성능은 내수압방식으로 수행하였으며, 수팽창성 지수재의 방수성능을 평가하기 위하여 5일간의 수침기간을 두었다. 수팽창성 지수재는 일반적인 형태와 비팽창성고무가 결합된 형태의 두가지 방식을 적용하였고, 가스켓은 일반적으로 가장 많이 사용되는 EPDM가스켓과 수팽창성지수재가 부착된 복합형 가스켓을 적용하였다. 세그먼트의 방수성능은 시공오차 및 세그먼트 변형에 크게 의존하며, 일반적으로 이러한 시공오차 및 세그먼트 변형은 연결부 벌어짐 (Gap)과 연결부 엇갈림 (Offset)으로 표현된다. 이 Gap과 Offset에 따른 방수성능의 변화를 관찰한 결과, 세그먼트의 방수성능은 시공오차 중 Gap의 영향을 크게 받는 것을 확인할 수 있었으며, Gap과 Offset에 대한 관리기준치가 제시되었다.

• Elastomers and Composites
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• 제42권4호
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• pp.232-237
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• 2007

가스켓 재료로서 널리 사용되고 있는 FKM, VMQ, EPDM, NBR을 연료전지 스택용 가스켓으로써의 적합성을 평가하기 위하여, 각각의 재료특성을 이용하여 최적상태의 배합물을 제작하고, 배합물의 특성을 살펴보았다. 최적의 상태를 만족하도록 만든 배합물에서 NBR 재료는 장기 화학적 물성에서, VMQ는 금속이온 용출성에서, EPDM은 가스투과성이 FKM에 비하여 열세로 나타났다. 배합물 물성에서 우수하다고 판단된 FKM으로 연료전지 스택용 가스켓을 제작하여 leak 평가를 실시한 결과, 체결압이 낮을수록, sealing pressure가 높을수록 짧은 시간에서 leak가 발생하였다. 또 Arrhenius Model을 이용하여 수명예측을 실시한 결과, $80^{\circ}C$에서 연속운전 시 가스켓의 수명은 60,000시간 이상 가능한 것으로 예측되었다.

• Journal of Welding and Joining
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• 제11권4호
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• pp.36-43
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• 1993

1)sector chamber II에서 가장 우려되었던 J5, J8의 변형량이 $28\mu\textrm{m}$,$36\mu\textrm{m}$ 이었으므로 목표 값 $50\mu\textrm{m}$을 충분히 보증할 수 있다. 2) Helicoflex gasket type으로 제작된 초도품 챔버에서는 140.deg.C bake-out후 이온 펌프만 으로 20시간 진공배기한 후의 진공도는 2*$10^{-9}$ Torr에 도달하였으며, 용접 type으로 제 작된 챔버에서는 2*$10^{-10}$ Torr에 도달하여서 진공도도 우수하였다. 3)표면조도에 민감한 Helicoflex gasket를 사용하지 않고 알루미늄 플랜지를 용접하여 AI gasketc 를 이용할 수 있기 때문에 초도품챔버에서와 같이 알루미늄 챔버와 스텐레스 스틸 부품을 연결하 는 stainless spool piece가 필요하지 않게 된다. 4)고가의 helicoflex gasket을 쓰지 않으므로 가격절감을 할 수 있다.

• 대한수학회논문집
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• 제12권1호
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• pp.157-163
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• 1997

Based on a n-regular polygon $P_n$, we show that $r_n = 1/(2 \sum^{[(n-4)/4]+1}_{j=0}{cos 2j\pi/n)}$ is the ratio of contractions $f_i(1 \leq i \leq n)$ at each vertex of $P_n$ yielding a symmetric gasket $G_n$ associated with the just-touching I.F.S. $g_n = {f_i $\mid$ 1 \leq i \leq n}$. Moreover we see that for any odd n, the ratio $r_n$ is still valid for just-touching I.F.S $H_n = {f_i \circ R $\mid$ 1 \leq i \leq n}$ yielding another symmetric gasket $H_n$ where R is the $\pi/n$-rotation with respect to the center of $P_n$.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.28-38
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• 2003

Finite element analysis of cylinder heat/block compound under assembly, thermal and firing condition were performed. FE model including two cylinders with gasket, head bolts, liners and valve seats was used. FE modeling method and boundary conditions were introduced. Stress distribution and deformation of cylinder head and block under each loading condition were presented. Gasket pressure distribution and bore distortion level were predicted. Measured data of bore distortion was compared with the analysis results. The analysis result showed similar trends with the experimental data. High cycle fatigue analysis on the basis of this result has been performed in order to find the critical areas of the engine assembly.

• 한국화재조사학회지
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• 제11권1호
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• pp.75-90
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• 2007

본 논문에서는 국내에서 옥외에 설치한 계기용변성기의 화재원인을 분석한 것이다. 이는 KSC IEC와 같은 공인된 규정에 의해 준수되었고, 현장에서 입증이 가능하도록 전개되었다. 결과적으로, 공정의 마무리가 불량한 계기용변성기의 개스킷 부분에서 화재 원인을 찾아내었다. 화재 과정을 추정하면, 미체결 개스킷에 기인한 계기용변성기에 수분이 침투한 것이다.

• 전기학회논문지
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• 제59권10호
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• pp.1770-1775
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• 2010

An acceleration life test for rubber gasket of pole transformer was performed. The Arrhenius method was applied as an accelerated degradation test. The failure mode was considered as an elongation, and the failure mechanism is counted as a heat. It is found that both the current material(NBR: Nitrile Butadiene Rubber) and recommended alternative material(HNBR: Hydrogenated Nitrile Butadiene Rubber) have the same Weibull distribution as a life characteristic. For life expectation 95% reliability level of characteristic life is used at using temperature. The test results for NBR and HNBR are 7.7 years and 28.0 years on $50^{\circ}C$ of using temperature, respectively.