• 한국지반환경공학회 논문집
• /
• 제23권1호
• /
• pp.31-37
• /
• 2022

본 연구는 기존 PVC코팅망의 성능 부족으로 인한 찢어짐으로 인근 피해 확대를 방지하기 위하여 고강도 선재 포획망을 제작하여 이를 방지하기 위한 기술을 개발하기 위해 시험을 진행한 것이다. 시험 방법은 국제 기준인 ISO 17746:2016을 참조하여 steel wire ring panel과 steel wire rope net panel, roll에 대한 장력시험(인장시험)에 대한 사항의 규정을 따라, 고강도 선재 포획망의 장력시험 시 고강도 선재 포획망 시편은 폭 1,000mm 이상, 최소 시편크기 1.0m²를 제작하였다. 시험결과의 하중-변위 곡선을 비교하여 기존의 PVC 코팅망 보다 성능이 얼마나 향상되었는지를 분석하였다.

• 대한기계학회논문집A
• /
• 제27권6호
• /
• pp.1034-1040
• /
• 2003

Tension mask is a part of CRT type devices, which is installed right behind glass-made front panel. Numerous slits on the thin metal sheet enable the electron beams emitted from posterior gun to be focused, resulting in enhanced definition. Flattened and enlarged displays necessitate the imposition of pretension on the masks, in order to improve the robustness of display quality against vibration or impact. High temperature assembly process subsequent to pretensioning, however, degenerates creep resistance of mask material, and common mask may become susceptible to undesirable elongation due to creep. Once tensile stress becomes high enough to induce creep deformation, pretension is substantially loosened. In this study, tension mask assembly is modeled as a combined structure of beams and wire array, and a numerical simulation is attempted for pretensioning followed by high temperature process. Based on a model study, creep occurrence is found to be probable and its adverse influence is quantified. As fur maintaining high tensile force, simply increasing pretension does not seem to be helpful. Instead, the structure of frame needs to be modified somehow, or material for mask needs to be selected properly.

• 한국기계가공학회지
• /
• 제19권5호
• /
• pp.60-66
• /
• 2020

In this paper, we describe a rope tension automatic equalizer that automatically adjusts several rope tensions connecting the elevator car and the counterweight. The automatic rope tension equalizer is composed of a body, ram, and rope shaft. The body includes a cylinder hole, in which a ram is assembled. A rope shaft is assembled in a hole in the ram. Moreover, the rope is fixed to the rope shaft, with a hole through which fluid can pass between each cylinder hole and the hole of the body. The central concept is that the force of each rope is evenly distributed by the hydraulic pressure between the ram and the body cylinder when the rope is pulled. The thickness of the jaw connecting the small and large diameters of the body of the rope tension automatic equalizer was 15 mm based on structural analysis. The results of the representative experiment to install the produced rope tension equalizer on the elevator revealed it was possible to reduce the rope tension deviation by more than 71 kg.

• 한국전산구조공학회논문집
• /
• 제21권3호
• /
• pp.287-294
• /
• 2008

이 연구에서는 교량 상부구조물의 보수 보강에 많이 사용되는 7연 강연선의 공용중 긴장력 관리를 위한 새로운 방법은 제안하였다. 제안된 스마트 강연선은 기존 강연선의 중앙 킹와이어를 강제튜브로 대체하고, 강제튜브의 내부에 FBG 광섬유센서를 설치하여 강연선의 변형률을 측정할 수 있도록 하였다. 내장된 센서를 통하여 이 스마트 강연선의 변형률을 쉽게 측정할 수 있으므로, 공용중 강연선의 긴장력을 모니터링할 수 있다. 본 연구에서 제안된 장력 모니터링 방법의 효용성을 증명하기 위하여 FBG센서 2개가 내장된 길이 7.0m인 스마트 강연선을 제작하고, 이를 길이 6.4m, 높이 0.6m인 RC T형 모형거더에 외장형 텐던으로 적용하였다. 그리고 이 시험거더에 대한 재하-제하시험을 실시하고 로드셀에서 계측된 긴장력과 스마트 강연선을 이용하여 예측한 긴장력을 비교하였다. 비교 결과, 제안된 스마트 강연선은 긴장력이 작용된 강연선의 장력을 정확하게 모니터링 하는데 유용함을 확인할 수 있었다.

• 소성∙가공
• /
• 제14권8호통권80호
• /
• pp.704-711
• /
• 2005

The influence of process parameters in drawn wire on residual stresses was investigated. Based on a FE-simulation of the wire drawing process, the effects of process parameters such as semi-die angle, reduction, friction coefficient and bearing length on the residual stresses were investigated. The validity of the FE-simulation results was verified by the comparison of the previous simulated results with experimental data. In this study, semi-die angle and die reduction have significant effect on the residual stresses at the surface of drawn wire. Several methods such as, addition of axial tension, application of skin pass, straightening in multi-roll straightener etc, were suggested in the previous studies to reduce the residual stresses. In this study, the results show that the concurrent application of skin pass with low die reduction and low semi-die angle at the final stage of drawing operation reduces dramatically the both axial and hoop residual stresses after drawing

• 한국해양공학회지
• /
• 제26권1호
• /
• pp.70-77
• /
• 2012

In this study, a numerical analysis of offshore installation using a floating crane with heave compensator is carried out in time domain. The motion analysis of crane vessels is based on floating body dynamics using convolution integral and the crane wire is treated as simple spring. The lifted structure is assumed as a rigid body with 3 degree-of-freedom translational motion. The heave compensator is numerically modelled by the generalized spring-damper system. Firstly, forced motion simulations of crane wire system are carried out to figure out the basic principle of heave compensator. The transfer function of crane wire system is obtained and effective wave period of heave compensator are found. Then, coupled analysis of crane vessel, crane wire, and lifted structure are performed in regular and irregular sea conditions. Two different crane vessels and two lifted structures (suction pile and manifold) are considered in this study. Through a series of numerical calculations, the effective zone of heave compensator is investigated with respect to wave period and crane wire length.

• Steel and Composite Structures
• /
• 제28권2호
• /
• pp.139-147
• /
• 2018

Moment frames have considerable ductility against cyclic lateral loads and displacements; however, sometimes this feature causes the relative displacement to exceed the permissible limits. This issue can bring unfavorable hysteretic behavior on the frame due to the reduction in the stiffness and resistance against lateral loads. Most of common bracing systems usually control lateral displacements through increasing stiffness while result in decreasing the capacity for energy absorption. This has direct effect on hysteresis curves of moment frames. Therefore, a system that is capable of both having the capacity of energy absorption as well as controlling the displacements without a considerable increase in the stiffness is quite important. This paper investigates retrofitting of a single-storey steel moment frame using a delayed wire-rope bracing system equipped with the ductile middle steel plate. The steel plate is considered at the middle intersection of wire ropes, where it causes cables to be continuously in tension. This integrated system has the advantage of reducing considerable stiffness of the frame compared to cross bracing systems as a result of which it could also preserve the frame's energy absorption capacity. In this paper, FEM models of a delayed wire-rope bracing system equipped by steel plates with different geometries have been studied, validated, and compared with other researchers' laboratory test results.

• 대한정형외과스포츠의학회지
• /
• 제4권2호
• /
• pp.133-137
• /
• 2005

주두 골절에 대한 치료적 수술 방법으로 장력대 강선 고정법은 골절의 고정과 유합에 유용한 방법으로 알려져 있으며, 이의 합병증으로 불유합, 운동 장애 및 강선의 피하 돌출 등이 보고되고 있으나 그 빈도는 많지 않다. 그 중 주관절의 회전 운동 장애에 대한 보고된 예가 없어 저자들은 전완 회내전과 회외전 장애를 각각 1례 경험하였기에 문헌고찰과 함께 보고하고자 한다.

• 전기학회논문지
• /
• 제64권12호
• /
• pp.1789-1795
• /
• 2015

The pulley-type tensioning device subjected to a maximum tension of 34 kN has been developed for 400 km/h high-speed railway. The tensioning device is to maintain the tension variation within 3% of the normal value, irregardless of temperature changes. Field tests shows that the tensioning device had a variation of tension which was as small as 0.6% as temperatures changed from $-5{\sim}7^{\circ}C$. Along with the tensions, we measured its X and Y movements due to the temperature changes. Based on a combination of its X and Y movements, we proposed a new performance index with which we can see if the tensioning device has troubles in operation without tension measurements.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 하계학술대회 논문집 C
• /
• pp.1296-1298
• /
• 1995

This paper presents the power cable with the concentric neutral wires of S-Z stranding. This type Cables, 22.9KV CN/CV Cables used in the distribution systems have been developed in order to improve bend, bend after torsion and tension charateristics. We have designed and made S-Z stranding machine, testing equipment etc., and have established the manufacturing technology of the equipment and the testing technology.