• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.797-801
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• 2003

This paper has the object of investigating natural frequencies of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. Vibration analysis that opening plate subjected to In-plane stress is presented in this paper. Finite element analysis of rectangular opening plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on Pasternak foundation, the Winkler foundation parameter is varied with 0, 10, 102, 103 and the shear foundation parameter is 0, 5, 10, 15. The ratio of In-plane force to critical load is applied as 0.2, 0.8, respectively. This paper analyzed varying opening Position and opening size.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.244-247
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• 2004

This study proposes the design method of the shear walls with openings using strut-and-tie models. Strut-and-tie models are constructed for opening near the middle of the wall and for opening near a wall boundary. These enables an admissible load path for the horizontal earthquake force. These models consider the size and position of opening effectively. Each model is suitable for the seismic response corresponding with lateral forces in a given direction to be considered. The proposed models are good agreements with nonlinear finite element analysis(DIANA) results.

• 한국자동차공학회논문집
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• 제18권1호
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• pp.93-98
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• 2010

An object of this study is to confirm the opening amount of the throttle valve that is begun the temperature separation of vortex tube for various engine speed and load condition in a common rail diesel engine. The vortex tube located at downstream of the exhaust manifold is a device separating the incoming exhaust gas to hot and cold stream. To find optimum separation efficiency of vortex tube, the opening amount of throttle valve has been investigated for various engine speed and load conditions. Engine speed was found that the influence of engine speed was dominant compared with that of engine load. As engine speed was increased, the throttle opening amount starting temperature separation was reduced.

• Steel and Composite Structures
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• 제10권1호
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• pp.69-85
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• 2010

The present paper presents a study on the behavior and design of corrugated web steel beams with and without web openings. In the literature, the web opening problem in steel beams was dealt with mostly for steel beams with plane web plates and research on the effect of an opening on a corrugated web was found out to be very limited. The present study deals mainly with the effect of web openings on the transverse load carrying capacity of steel beams with sinusoidally corrugated webs. A general purpose finite element program (ABAQUS) was used. Simply supported corrugated web beams of 2 m length and with circular web openings at quarter span points were considered. These points are generally considered to be the optimum locations of web openings for steel beams. Various cases were analyzed including the size of the openings and the corrugation density which is a function of the magnitude and length of the sine wave. Models without web holes were also analyzed and compared with other cases which were all together examined in terms of load-deformation characteristics and ultimate web shear resistance.

• 대한기계학회논문집
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• 제14권6호
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• pp.1568-1575
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• 1990

본 연구에서는 중앙균열을 가진 SB41강의 평판이 하중제어와 변형률제어 피로 상태에서 소규모 항복, 대규모 항복, 또는 전면 항복의 각 응력에서 피로균열 진전 속 도와 J적분 범위, .DELTA.J와의 관계를 조사하는 한편, 피로균열 진전 속도를 지배하는 국 소적 역학 인자인 균열선단 개구변위, COD와 균열 진전 속도와 관계 및 그 특성을 고 찰하였다.

• 한국정밀공학회지
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• 제22권6호
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• pp.152-158
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• 2005

The stress conditions acting on the practical structure are complex, and thus most cracks existing in the practical structures are under mixed-mode loading conditions. The effect of shear load component of mixed-mode loading acts more greatly in the stage of crack initiation and initial propagation than crack propagation stage. Hence, research on the behavior in the stage of crack initiation and initial propagation need to be examined in order to evaluate behavior of mixed-mode fatigue cracks. In this study, the crack tip displacement(CTD) was measured by using the direct measuring method(DMM). We examined the behavior at crack tip by determining crack opening load$(P_{op})$. From the test results, the propagation behavior of mixed-mode fatigue cracks was evaluated by considering mixed-mode crack closure. Also, we examined the characteristic of crack propagation under mixed-mode loading with crack propagation direction.

• 한국추진공학회지
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• 제11권6호
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• pp.35-41
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• 2007

부하율은 모터구동 밸브에서 밸브 스템에 가해지는 부하(load) 변화에 따라 구동기 torque와 스템 thrust 사이의 상관관계가 변하는 현상이다. 본 논문에서는 게이트밸브의 열림행정에서 발생되는 부하율 특성을 분석하고 밸브 성능평가시 적용하는 부하율의 타당성에 대해 기술하였다. 또한, 총 40대의 게이트밸브에 대해 정적시험 및 동적시험을 수행하고 본 연구에서 개발한 열림행정에서의 부하율 평가 방법론을 적용하여 각 밸브의 열림행정 부하율을 평가한 결과를 수록하였다. 연구결과로서 열림행정의 부하율은 차압이 150 psi보다 높은 경우 (-)값으로 나타났으며, 이러한 현상은 유체 차압이 높을수록 크게 나타나는 결론을 얻었다.

• 대한기계학회논문집A
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• 제34권6호
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• pp.725-730
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• 2010

부정정계 배관의 두께 관통 후 파단전누설 거동과 균열개구변위는 정정계 배관과 비교하여 연구 하였다. 부정정 배관은 균열 발생으로 인한 최대 강도의 감소가 비교적 적었다. 부정정 배관계의 파단 전누설 거동은 정정계 배관보다 더 안전 하였다. 균열개구변위는 미관통균열을 가지는 배관에서 균열 관통 후 평가하기 위하여 제안된 소성힌지를 사용하여 평가하였다.

• 한국생산제조학회지
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• 제9권6호
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• pp.82-88
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• 2000

The effect of the welding for the offshore structure in the TMCP steel on the fatigue crack propagation rate and crack opening-and-closure behavior was examined. The welding anisotropy of the TMCP steel and crack propagation characteristics of the excessive loading were reviewed. (1) It seemed that a heat which was generated by the welding made a compressive residual stress over the base metal, so fatigue crack propagation rate was placed lower than in case of the base metal. (20 In the base metal, an effect of the anisotropy which has an effect of fatigue crack propagation rate of the excessive load and the constant amplitude laos was not found but in the welding material case, fatigue crack propagation rate of the excessive load in the specimen of the width direction was located in the retard side as compared with a specimen rolling direction. (3) A crack opening ratio of the used TMCP stel in this study was not changed after excessive loading but a retard phenomenon of crack propagation was observed. Consequently, it was thought that all of the retard phenomenon of crack propagation did not only a cause of the crack opening-and-closure phenomenon.

• Structural Engineering and Mechanics
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• 제31권6호
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• pp.679-696
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• 2009

The paper aims at analyzing the stress distribution around an underground opening that is subjected to non-symmetrical surface loading with emphasis on opening shapes with sharp corners and the stress concentrations developed at these locations. The analysis is performed utilizing the BIE method coupled with the Neumann's series. In order to implement this approach, the special recurrent relations for half plane were proven and the modified Shanks transform was incorporated to accelerate the series convergence. To demonstrate the capability of the developed approach, a horseshoe shape opening with sharp corners was investigated and the location and magnitude of the maximum hoop stress was calculated. The dependence of the maximum hoop stress location on the parameters of the surface loading (degree of asymmetry, size of loaded area) and of the opening (the opening height) was studied. It was found that the absolute magnitude of the maximum hoop stress (for all possible surface loading locations) is developed at the roof points when the opening height/width ratio is relatively large or when the pressure loading area is relatively narrow (compared to the roof arch radius), and contrarily, when the opening height/width ratio is relatively small or when the surface pressure is applied to a relatively wide area, the absolute magnitude of the maximum hoop stress is developed at the bottom sharp corner points.