• 제목/요약/키워드: contact pressure

검색결과 1,705건 처리시간 0.023초

Evaluation of APR1400 Steam Generator Tube-to-Tubesheet Contact Area Residual Stresses

  • KIPTISIA, Wycliffe Kiprotich;NAMGUNG, Ihn
    • 한국압력기기공학회 논문집
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    • 제15권1호
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    • pp.18-27
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    • 2019
  • The Advanced Power Reactor 1400 (APR1400) Steam Generator (SG) uses alloy 690 as a tube material and SA-508 Grade 3 Class 1 as a tubesheet material to form tube-to-tubesheet joint through hydraulic expansion process. In this paper, the residual stresses in the SG tube-to-tubesheet contact area was investigated by applying Model-Based System Engineering (MBSE) methodology and the V-model. The use of MBSE transform system description into diagrams which clearly describe the logical interaction between functions hence minimizes the risk of ambiguity. A theoretical and Finite Element Methodology (FEM) was used to assess and compare the residual stresses in the tube-to-tubesheet contact area. Additionally, the axial strength of the tube to tubesheet joint based on the pull-out force against the contact joint force was evaluated and recommended optimum autofrettage pressure to minimize residual stresses in the transition zone given. A single U-tube hole and tubesheet with ligament thickness was taken as a single cylinder and plane strain condition was assumed. An iterative method was used in FEM simulation to find the limit autofrettage pressure at which pull-out force and contact force are of the same magnitude. The joint contact force was estimated to be 20 times more than the pull-out force and the limit autofrettage pressure was estimated to be 141.85MPa.

접촉 면적과 접촉면 압력분포에 대한 마찰의 영향 (The Effects of Friction on the Contact Area and the Distribution of Contact Pressure)

  • 이문주;조용주
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1999년도 제30회 추계학술대회
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    • pp.193-199
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    • 1999
  • In the 3-Dimensional contact of the smooth spheres, the effects of friction on the contact area and the distribution of contact pressure was studied numerically. The contact area and pressure distribution was evaluated for the only normal load and for the case of a normal load in the presence of a tangential traction. To do this work, the technique of simple discretization using the load . displacement relationship for a uniformly distributed load of a rectangular patch was used.

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곡선부 차륜/레일 접촉압력에 따른 레일마모진전 경향 분석 (Analysis of Rail Wear Rate according to Wheel/Rail Contact Pressure on Curved Track)

  • 성덕룡
    • 한국철도학회논문집
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    • 제20권4호
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    • pp.512-520
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    • 2017
  • 일반적인 철도에서는 차륜과 레일의 마찰력을 이용하여 열차가 주행하게 된다. 차륜과 레일 사이에는 접촉압력이 발생하게 되고, 차량의 중량, 속도, 사행동, 접촉점 등에 따라 접촉압력의 크기가 변화하게 된다. 본 연구에서는 곡선부 차륜/레일에 대한 유한요소해석을 통해 접촉특성을 분석하였으며, 구름접촉피로시험을 통해 접촉압력에 따른 차륜/레일의 피로손상 및 마모율을 분석하였다. 구름접촉피로시험결과, 일반 및 열처리레일은 차륜에 비해 마모율이 높았으며, 일반 및 열처리레일마모율은 일정한 반복횟수 이상에서 급격히 증가하는 것으로 분석되었다. 또한, 일반레일이 열처리레일 보다 약 7~15% 마모율이 높았으며, 접촉압력 900~1,500MPa 범위에서 접촉압력에 따른 레일마모율에 대한 회귀분석식을 제시하였다.

와이퍼 블레이드의 누름압 해석 (Contact Pressure Analysis of a Windshield Wiperblade)

  • 이병수;신진용
    • 한국자동차공학회논문집
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    • 제14권3호
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    • pp.51-57
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    • 2006
  • The contact pressure distribution between a rubber wiper blade and a glass windshield is a major factor for wiping performance. A modeling and simulation method has been developed to forecast the contact pressure distribution on a wiper blade. For modeling multi-body dynamics of an wiper linkage system and flexible nature of wiper blade, ADAMS and ADAMS/flex are employed. A simulation study has been also conducted to obtain contact pressure distribution. Comparison between simulation and measurement is provided to ensure fidelity of the model and the simulation method.

Non-uniform virtual material modeling on contact interface of assembly structure with bolted joints

  • Cao, Jianbin;Zhang, Zhousuo;Yang, Wenzhan;Guo, Yanfei
    • Structural Engineering and Mechanics
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    • 제72권5호
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    • pp.557-568
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    • 2019
  • Accurate modeling of contact interface in bolted joints is crucial in predicting the dynamic behavior for bolted assemblies under external load. This paper presents a contact pressure distribution based non-uniform virtual material method to describe the joint interface of assembly structure, which is connected by sparsely distributed multi-bolts. Firstly, the contact pressure distribution of bolted joints is obtained by the nonlinear static analysis in the finite element software ANSYS. The contact surface around bolt hole is divided into several sub-layers, and contact pressure in each sub-layer is thought to be evenly. Then, considering multi-asperity contact at the micro perspective, the relationship between contact pressure and interfacial virtual material parameters for each sub-layer is established by using the fractal contact theory. Finally, an experimental platform for the dynamic characteristics testing of a beam lap structure with double-bolted joint is constructed to validate the efficiency of proposed method. It is found that the theoretical results are in good agreement with experimental results by impact response in both time- and frequency-domain, and the relative errors of the first four natural frequencies are less than 1%. Furthermore, the presented model is used to examine the effect of rough contact surface on dynamic characteristics of bolted joint.

압축링-유막간의 접촉압력 거동에 관한 유한요소해석 (Finite Element Analysis of Contact Pressure Behavior in Compression Ring-Oil Film)

  • 김청균;김한구;한동철
    • Tribology and Lubricants
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    • 제11권4호
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    • pp.53-57
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    • 1995
  • The contact pressure behavior is examined by means of a finite element analysis. The oil film between the piston ring and cylinder liner is analyzed on the basis that it behaves like a polymer material. The calculated results indicate that a shape of sloping edge with a straight line, which is designated as a Model III, shows a good performance on the contact pressure behavior for the increased speed. Obviously, the ring face profiles play an important role on the contact pressure between compression ring and oil film.

CMP 후 세정용 PVA 브러쉬의 접촉압력 분포 측정 (Contact Pressure Distribution Measurement of PVA Brush for Post CMP Cleaning)

  • 유선중;김덕중
    • 반도체디스플레이기술학회지
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    • 제15권4호
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    • pp.73-78
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    • 2016
  • Contact pressure distribution between PVA brush and semiconductor wafer was measured by developing a test setup which could simulates the post CMP cleaning process. The test set-up used thin film type pressure sensor which could measure the pressure distribution of contact area with the resolution of $15.5ea/cm^2$. As the experimental results, it was verified that there had been severe contact pressure non-uniformity along the axis of the brush and between the adjacent projections on the brush's surface. These results should be considered when developing post CMP cleaning stage or designing the PVA brush.

브레이크 스퀼 해석에서 접촉압력분포의 영향에 관한 연구 (The study on the influence of contact pressure distribution on brake squeal analysis)

  • 이호건;손민혁;서영욱;부광석;김흥섭
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.1120-1124
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    • 2007
  • Recently in the automotive brake industry brake squeal noise has become one of the top automotive quality warranty issues. The contact pressure is used to predict friction coupling in the brake squeal analysis. The formulation of friction coupling has performed by nonlinear static analysis prior to the complex eigenvalue analysis. This paper proposes a validation methodology of squeal analysis using modal testing and contact analysis and examines the effect of predicted contact pressure that leads to the discrepancy between unstable complex mode and squeal frequency. This studies compose a three step validation process : examining the modal characteristics of component and assembly loaded contact pressure using modal testing and FEM analysis and verifying the contact pressure distribution using nonlinear static analysis and experiment. Finally, the unstable modes from complex eigenvalue analysis and realistic squeal frequency from the noise dynamometer are investigated.

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Pressure Contact Interconnection for High Reliability Medium Power Integrated Power Electronic Modules

  • Yang, Xu;Chen, Wenjie;He, Xiaoyu;Zeng, Xiangjun;Wang, Zhaoan
    • Journal of Power Electronics
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    • 제9권4호
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    • pp.544-552
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    • 2009
  • This paper presents a novel spring pressure contact interconnect technique for medium power integrated power electronics modules (IPEMs). The key technology of this interconnection is a spring which is made from Be-Cu alloy. By means of the string pressure contact, sufficient press-contact force and good electrical interconnection can be achieved. Another important advantage is that the spring exhibits excellent performance in enduring thermo-mechanical stress. In terms of manufacture procedure, it is also comparatively simple. A 4 kW half-bridge power inverter module is fabricated to demonstrate the performance of the proposed pressure contact technique. Electrical, thermal and mechanical test results of the packaged device are reported. The results of both the simulation and experiment have proven that a good performance can be achieved by the proposed pressure contact technique for the medium power IPEMs.

곡면 다듬질에서 접촉해석에 근거한 유연공우 경로 설정 (Determination of Flexible Tool Path in Curved Surface Finishing Based on Contact Analysis)

  • 조성산;이승영;유용균
    • 한국정밀공학회지
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    • 제17권11호
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    • pp.69-74
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    • 2000
  • Roughness of curved surfaces finished with flexible tools depends on the tool/work contact pressure and area. In this study, non-Hertzian closely conforming elastic contact theory is employed to analyze the tool/work contact and to generate a tool path producing a constant pressure at initial contact points. Finishing experiments on curved surfaced are conducted using the tool path. For comparison, curved surface finishing is also performed along the tool path producing a constant tool/work interference depth. It is demonstrated that the tool path of constant contact pressure improves the finished surface roughness.

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