• 방사성폐기물학회지
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• 제12권4호
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• pp.299-314
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• 2014

인양장비는 원자력발전소에서 발생하는 사용후핵연료를 운반하는 운반용기를 인양하기 위해 사용된다. 본 연구는 원자력 안전위원회고시 제2013-27호와 미국 10CFR Part 71 ${\S}71.45$에서 규정하는 기술수준에 따라 이론적인 방법과 유한요소방법으로 인양장비의 구조적안전성을 평가하였다. 이론적으로 평가한 결과 모든 구성 요소에서의 응력이 응력제한치 내에 있어 운영상 발생하는 구조적 안전성을 확보하고 있는 것으로 판단하였다. 또한 유한요소해석을 통한 평가결과, 항복과 극한조건 모두에서 설계기준을 만족하는 것으로 평가되었다. 모든 구성요소에서 충분한 안전여유도(항복조건에서 3 이상의 안전율, 극한조건에서 5 이상의 안전율)를 갖는 것으로 나타나 구조적으로 안전하다고 판단하였다.

• 한국산학기술학회논문지
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• 제19권10호
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• pp.648-654
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• 2018

본 노면에 설치되어있는 맨홀의 지속적인 관리를 위해서는 맨홀의 개폐가 쉬워야 한다. 가혹한 조건하에 있는 맨홀은 틀과 커버가 고착되어 개폐가 어렵기 때문에 맨홀을 열 때 부양이 가능한 맨홀이 요구된다. 본 연구에서는 잠금식 맨홀을 부양식 맨홀로 개선하기 위한 부양 기구의 설계를 진행하였다. 잠금식 맨홀의 기구는 중앙에 위치한 볼트를 돌리면 볼트와 연결된 허브가 하강하고, 허브와 연결되어 있는 후크를 회전시키게 된다. 후크의 끝단이 맨홀 틀에 걸리도록 되어있다. 본 연구에서는 맨홀의 부양이 가능하도록 후크에 보조장치를 설치하도록 하였다. 부양 기능을 수행할 후크의 항복응력의 70%를 기준으로 약 300kg의 부양력을 지지할 수 있도록 구조를 설계하였다. 유한요소법을 이용한 구조해석을 통하여 형상 설계를 수행하였다. 우선 단순화된 2차원 모델로 1차 기초설계를 수행하고, 3차원 모델을 통하여 부착위치와 형상을 설계하였다. 설계된 형상에 대하여 구조적 문제점을 찾아보기 위하여 3D 프린팅을 통하여 축소 모델을 출력하였고, 기능이 작동함을 확인하였다. 최종적으로 가공을 통하여 부양 기구를 제작하여 기존의 잠금식 맨홀에 적용한 결과 평균 6.1 mm 정도의 부양이 가능함을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.219-223
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• 2001

This paper introduces DS/Block-Structure - a structural analysis module of DS/Block, which is a Design System to simulate the behavior of a ship block in various crane operations and to evaluate its structural deformation using the finite element method. It runs based on a CAD program, Pro/ENGINEER, and structural analyses are performed by a developed FE code. Boundary conditions for the FE analysis of a ship block under lifting and turnover operation are also considered.

• 대한산업공학회지
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• 제12권2호
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• pp.1-11
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• 1986

This study is concerned on computerized analysis of COG, torques and EMG amplitudes in weight-lifting motion. The results show that; (1) torques on major joints show a rather consistent relationship with respect to the sequence of four distinct motions in weight-lifting, (2) analysis of EMG amplitudes is a sensitive measure of both athlete's skill and his potential capability, and (3) range of COG variations can be used as indicator of motion stability, existence of undesirable posture, and target muscle for intensive training. A computerized routine, which includes analyses on COG, EMG and torque, is a scientific tool for coaching athletes. In addition, an Expert System which includes CAD routine was developed in order to promote better understanding for athletes and coaches.

• Safety and Health at Work
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• 제2권3호
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• pp.236-242
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• 2011

Objectives: To determine the feasibility of predicting static and dynamic peak back-compressive forces based on (1) static back compressive force values at the lift origin and destination and (2) lifting speed. Methods: Ten male subjects performed symmetric mid-sagittal floor-to-shoulder, floor-to-waist, and waist-to-shoulder lifts at three different speeds (slow, medium, and fast), and with two different loads (light and heavy). Two-dimensional kinematics and kinetics were captured. Linear regression analyses were used to develop prediction equations, the amount of predictability, and significance for static and dynamic peak back-compressive forces based on a static origin and destination average (SODA) backcompressive force. Results: Static and dynamic peak back-compressive forces were highly predicted by the SODA, with R2 values ranging from 0.830 to 0.947. Slopes were significantly different between slow and fast lifting speeds (p < 0.05) for the dynamic peak prediction equations. The slope of the regression line for static prediction was significantly greater than one with a significant positive intercept value. Conclusion: SODA under-predict both static and dynamic peak back-compressive force values. Peak values are highly predictable and could be readily determined using back-compressive force assessments at the origin and destination of a lifting task. This could be valuable for enhancing job design and analysis in the workplace and for large-scale studies where a full analysis of each lifting task is not feasible.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2228-2230
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• 2002

The research presented in this paper focuses on a method for the detection of High Impedance Fault(HIF). The method will use the Lifting and neural network system. HIF on the multi-grounded three-phase four-wires primary distribution power system cannot be detected effectively by existing over current sensing devices. These paper describes the application of lifting scheme to the various HIF data. These data were measured in actual 22.9kV distribution system. Wavelet transform analysis gives the frequency and time-scale information. The neural network system as a fault detector was trained to discriminate HIF from the normal status by a gradient descent method. The proposed method performed very well by proving the right state when it was applied staged fault data and normal load mimics HIF, such as arc-welder.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.107-112
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• 2005

During assembling the ship block, the lifting and turnover events are not only inevitable but also very important for safety aspects and block accuracy. However, they have been executed in empirical ways rather than numerical ways in consideration of the building schedule. In this paper, a structural analysis has been carried out for the container ship side block that collapsed in the course turnover stage. As a result, the causes of collapse and countermeasure plans are presented.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.27-34
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• 1999

This study presents the concept and the effects of the lifting two supports method that makes get economical design sections and efficient stress condition. The analysis of relation between critical sections and ratios Is done. Also, connection between critical sections and design variable is analyzed. In order to resolve the effects of the lifting two supports method, sections which was designed with the existing method, lifting support method, are used. Finally, it is proved that the new method is more efficient than the existing methods in economy and structure.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 공동학술발표회
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• pp.248-248
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• 2017

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1188-1195
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• 2007

The vertical forces in rail fasteners at areas of bridge transitions near the embankment and on the pier will occur due to different deformations of adjoining bridges caused by the trainloads, the settlement of supports, and the temperature gradients. The up-lifting forces is not large problem in the blast track because the elasticity of blast and rail pad buffs up-lifting effect. But, it is likely to be difficult to ensure the serviceability of the railway and the safety of the fastener in the end in that concrete slab track consist of rail, fastener, and track in a single body, delivering directly the up-lifting force to the fastener if the deck is bended because of various load cases, such as the end rotation of the overhang due to the vertical load, the bending of pier due to acceleration/braking force and temperature deviation, the settlement of embankment and pier, the temperature deviation of up-down deck and front-back pier, and the rail deformation due to wheel loads. The analysis of the rail fastener is made to verify the superposed tension forces in the rail fastener due to various load cases, temperature gradients and settlement of supports. The potential critical fasteners with the highest uplift forces are the fastener adjacent to the civil joint. The main influence factors are the geometry of the bridge such as, the beneath length of overhang, relative position of bridge bearing and fastener, deflection of bridge and the vertical spring stiffness of the fastener.