• 한국기계가공학회지
• /
• 제19권2호
• /
• pp.89-96
• /
• 2020

In this study, we developed a finite element model for the built-in bottom-freezer type refrigerator and then used the structural analysis method to analyze and evaluate the deflection of the doors. We tested the validity of the developed analytical model by measuring the deflection of the hinge when loads were applied to the upper and lower hinges of the refrigerating compartment and compared these with the analysis results. The comparison of the vertical displacement of the measured result and the analysis result showed an error ratio of up to 12.8%, which indicates that the analytical model is consistent. Using the analytical model composed of the cabinet, hinges and doors, we performed analyses for two cases: both doors closed, and the refrigerating door open. Since the maximum vertical displacement of the refrigerating compartment door (R-door) with the food load is smaller than the gap between the lower surface of the R-door and the upper surface of the freezer compartment door (F-door), it is judged that the R-door and the F-door do not contact when the doors are opened or closed. In addition, the analysis result showed that the difference between the vertical displacement at the hinge on the opposite side and the hinge side of the R-door is favorably smaller than the management criterion of the refrigerator manufacturer.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1867-1870
• /
• 2005

The celestial navigation is one of alternatives to GPS system and can be used as a backup of GPS. In the celestial navigation system using more than two star trackers, the vehicle's ground position can be solved based on the star trackers' attitude information if the vehicle's local vertical or horizontal angle is given. In order to determine accurate ground position of flight vehicle, the high accurate local vertical angle measurement is one of the most important factors for navigation performance. In this paper, the Earth geophysical deflection was analyzed in the assumption of using the modern electrolyte tilt sensor as a local vertical sensor for celestial navigation system. According to the tilt sensor principle, the sensor measures the tilt angle from gravity direction which depends on the Earth geoid surface at a given position. In order to determine the local vertical angle from tilt sensor measurement, the relationship between the direction of gravity and the direction of the Earth center should be analyzed. Using a precision orbit determination software which includes the JGM-3 Earth geoid model, the direction of the Earth center and the direction of gravity are extracted and analyzed. Appling vector inner product and cross product to the both extracted vectors, the magnitude and phase of deflection angle between the direction of gravity and the direction of the Earth center are achieved successfully. And the result shows that the angle differences vary as a function of latitude and altitude. The maximum 0.094$^{circ}$angle difference occurs at 45$^{circ}$latitude in case of 1000 Km altitude condition.

• 한국지반공학회논문집
• /
• 제38권6호
• /
• pp.29-39
• /
• 2022

도심지 원형 수직구 굴착 시 주변 지반의 침하는 포장 하부에 설치된 인프라시설의 안정성 뿐만 아니라 상부구조의 안정성에 큰 영향을 미친다. 배면지반의 침하량을 예측하는 방법은 지반조건, 벽체 변위, 해석 방법 등에 따라 달라지므로 근접시공 설계자는 합리적으로 침하량을 예측해야한다. 본 연구에서는 3차원 유한요소해석을 활용하여 굴착심도별로 지하수의 침투에 따른 영향을 고려하기 위해 비정상류, 정상류, 지하수를 고려하지 않은 조건으로 배면지반의 침하와 벽체의 변위 그리고 토압분포를 검토하였다. 수치해석결과, 배면지반의 침하량과 침하영향범위는 비정상류 상태가 정상류 상태보다 크게 발생하였으나 벽체의 수평변위는 반대로 정상류 상태가 비정상류 상태보다 크게 나타났다. 침하량의 크기는 굴착 깊이에 따라 다르게 나타났으며 굴착 깊이 별로 토사층에서 가장 크고 풍화암층, 연암층 순으로 감소하였다. 또한 수압을 포함한 수평응력값을 기존의 Rankine 토압식과 비교했을 때 토사지반에서는 유사한 경향을 보이나 암반층에서는 수치해석 결과보다 작은 토압형태가 나타남을 확인 할 수 있었다.

• 한국해양공학회지
• /
• 제23권6호
• /
• pp.44-52
• /
• 2009

In this study, the behavior of a breasting dolphin with various dolphin heights and formations in the coastal area of Incheon was investigated. The dynamic deflection, shear stress, and moment of the pile were analyzed using the coefficient of the horizontal subgrade reaction that resulted from loading tests of different DWT (Dead Weight Tonnage). In the case of a vertical pile type dolphin, the deflection, shear stress, and moment increased as the dolphin height increased. In the case of the battered pile type dolphin, small values of shear stress and moment were shown at a low dolphin height, and the characteristics of the dynamic behavior of the dolphin showed that the deflection, shear stress, and moment increased as the pile slope of the dolphin decreased or the DWT increased.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.10-14
• /
• 2006

FBG sensors are able to measure the strain of structures more easily and durable than electronic resistance gages and thus many researches are on the way to apply the FBG sensor for response monitering of infrastructures. This study investigates the deflection estimation technique using FBG sensors. Several FBG sensors are multiplexed in single optical fiber and installed. in parallel pairs along the length of the structure. The measured strains at the top and bottom of a cross section can be transferred to the curvature of the section which can be used to calculate its displacement. It has been demonstrated that the estimated deflections using the FBG sensor are compared well with the readings from displacement transducers. The results show that the proposed instrumentation technique is capable of estimating the vertical deflection of the structures for various loading conditions including impact and dynamic loads, which is crucial in the structural health monitoring.

• 한국농공학회지
• /
• 제40권1호
• /
• pp.78-87
• /
• 1998

In this study, semi-rigid light-weight framed structures analysis model (SERIFS) was developed by advancing the LEIFS model. This model enables us to analyze simultaneous effects of large deflection and semi-rigid connection by computing unbalanced load occurring in the process of repeated loading through equalization of bending moments and torsion. This model is also able to handle the effect of the semi-rigid connection and large deflection by modifying the elastic stiffness matrix using moment-rotation behavior of connection. Moment-rotation behavior of the semi-rigid connection was adopted from the experimental results of load-vertical displacement of frame element In conclusion, this model achieves to analyze the nonlinear and large deflection behavior on the semi-rigid and light-weight steel frame connection.

• 한국정밀공학회지
• /
• 제15권5호
• /
• pp.19-27
• /
• 1998

Color Display Tube (CDT) used in computer monitors, consists of many components. Deflection Yoke(DY) among them supplies the vertical and horizontal magnetic fields so that the spatial trajectories of electron beams are deflected according to the synchronization signals. If the magnetic fields are not correctly formed, there will be color blurring or blooming by a mis-convergence of each beam and the color image on screen may not be clear. Therefore, in the manufacture of DY. its quality is strictly examined to get the desired convergence and the occurred mis-convergence can be cured by sticking ferrite sheets on the inner part of DY. However, because it needs expert's knowledge and experience to find the proper position of the sheet, this article introduces an intelligent controller that the knowledge-base represented by a neuro-fuzzy model is used to find the optimal position of the ferrite sheet for the convergence.

• International Journal of Aeronautical and Space Sciences
• /
• 제7권1호
• /
• pp.99-105
• /
• 2006

In this study, nonlinear static and dynamic aeroelastic analyses for a high-aspect-ratio wing have been performed. To achieve these aims, the transonic small disturbance (TSD) theory for the aerodynamic analysis and the large deflection beam theory considering a geometrical nonlinearity for the structural analysis are applied, respectively. For the coupling between fluid and structure, the transformation of a displacement from the structural mesh to the aerodynamic grid is performed by a shape function which is used for the finite element and the inverse transformation of force by work equivalent load method. To validate the current method, the present analysis results of a high-aspect-ratio wing are compared with the experimental results. Static deformations in the vertical and torsional directions caused by an angle of attack and gravity loading are compared with experimental results. Also, static and dynamic aeroelastic characteristics are investigated. The comparisons of the flutter speed and frequency between a linear and nonlinear analysis are presented.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.754-755
• /
• 2015

In this research, moisture contents and roof deflection of two test-bed Korean traditional timber houses, Hanoks, were monitored. The monitored houses are consisted of two types of Hanoks. One is a one-story traditional Hanok built by traditional construction method, and the other is a two-storied new-styled Hanok built by modernized construction method. The monitoring has been carried out for about thirty months. The moisture contents and roof deflections were analyzed and compared. The moisture contents of the traditional Hanok built by raw wood were somewhat higher than that of the new-styled Hanok built by glued structural wood. The mean vertical deflection of angle rafters of traditional Hanok is about twice more than that of the new-styled Hanok.

• 한국공간구조학회:학술대회논문집
• /
• 한국공간구조학회 2006년도 춘계 학술발표회 논문집 제3권1호(통권3호)
• /
• pp.256-264
• /
• 2006

This paper describes the formulation of rectangular flat shell element that is modeled with the six degree of freedoms including a rotational degree of freedom. The rectangular finite element matrix with a rotational degree of freedom is developed using a beam stiffness matrix and compared with other methods. The outputs of the quantity of vertical deflection of cantilever beam show us the improving evidence of the Frame-Shell finite element matrix in a calculation of vertical deflections of cantilever beam.