• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.493-494
• /
• 2009

Two strengthened columns and an unstrengthened control column were tested to failure under cyclic lateral load combined with a constant axial load to effect of anchorage of T-shaped steel plate in the strengthened column using wire rope units. Main variables considered were anchorage method of T-shaped steel plate. Tested columns were compared with those of conventionally tied columns tested by research of before. Test results showed that lateral load capacity and the displacement ductility ratio of anchorage of T-shaped steel plate in the strengthened column increased 40% and 130% than unstrengthened column, respectively. In particular, at the same effective lateral reinforcement index, a much ductility ratio was observed in the strengthened columns than in the tied columns.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.12
• /
• pp.2785-2792
• /
• 2013

An elevator is driven by the friction between the pulley and wire rope. A balancing counter weight is connected to the elevator car with a wire rope. This structure is essential to drive elevators while it always has weight unbalance problems on each side. The overbalance-ratio of elevators may be an important factor for safety and structural efficiency; however, it is not yet clearly defined in the Requirements of Korea Elevator Inspection. This paper describes these "weight unbalance ratio" for control of elevators to reduce the number of accidents. It includes the analysis of current elevator maintenance situations and also proposes some fundamental improvement schemes for safety.

• Journal of the Korean GEO-environmental Society
• /
• v.23 no.1
• /
• pp.31-37
• /
• 2022

This study is focused on developing a technology to prevent high-strength wire net from expanding damage due to insufficient performance of the existing PVC coating net. For the test method, reference was made to ISO 17746, an international standard. In addition, as a result of referring to the test criteria, a wire net was fabricated with a width of 1,000 mm or more a size of 1 m² sample. load-displacement curve of the test results was compared to analyze how much performance was improved compared to the existing PVC coating net.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.24 no.2
• /
• pp.55-64
• /
• 1988

Stow nets have widely been used in the western sea of Korea from the olden age. The original structure of a stow net is a large square-sectional bag net made of 4 netting panels, and the front fringes of top and bottom panels are connected to the top and bottom beams respectively. Wire ropes, which is originated from the holding anchor are gradually forked and biforked, and finally 4 pieces of wire rope (biforked pendants) are jointed to each beam. Much convenience caused by long and heavy beams were problemed, then some studies have been carried out to improve the net since 1930's. The most effective improvement were achieved in 1980 by Mr. Han and his colleagues. The key point of improvement was that the beams were removed and the belt shaped shearing device made by canvas was attached to the side panels, the head rope and ground rope to the front fringe of top and bottom panel, and biforked pendants are joined to the shearing device. Even though this is the epoch-making improvement of a stow net, the further study should be required to find out more effective method. The authors carried out a model experiment on the stow net to determine the vertical and horizontal opening of a net mouth, and also examine the front, top and side-view configuration of the net. The model net was constructed depending on the Similarity Law of Fishing Gear in 1/10 and 1/20 scale and set against to the current at shallow and speedy flowing channel. The vertical and horizontal openings were determined by using scaled bamboo poles, and the configuration was observed by using specially prepared observation platform and underwater observation glass, and also photographed by using specially prepared underwater photographic equipment. The results obtained can be summarized as follows: 1. The opening height and width of the shearing device varied in accordance with the relative length of the biforked pendants. Considering the height and width of shearing device in 6 cases of the arrangement system of biforked pendants, the best result was obtained in the case that the 2nd, 3rd and 4th pendents from the bottom-most was 5%, 9% and 4% longer than that. 2. On the top-view configuration the excessive deformation of head rope and ground rope were observed. In the actual net, 54m long head rope and ground rope were attached to the front fringe of top and bottom panels so that the head rope may be lifted to make the net mouth open highly. But actually the head rope and the ground rope are streamed backward without any lift, and also the netting followed the ropes were deformed until the 2/5 in the whole length of the net. This deformation may be guessed to disturb the entrance of fish school into the net and also caused the net to get caught by obstacles in the sea bed and to be broken largely. 3. Hydrodynamic resistance R of the actual net may be deduced as R(kg)=29.2$\times$103 v1.65. It is also expressed as R(kg)=5.9$\times$d/l$\times$ab v1.65. depending on the formula deduced by Koyama to estimate the resistance of trawl nets, where d/l denote the ratio between diameter of netting twine and length of mesh leg in every part of side panel, a and b, the stretched circumference of the mouth and the stretched length of the net, respectively.

• Journal of the Korea Concrete Institute
• /
• v.27 no.3
• /
• pp.207-214
• /
• 2015

This study examined the feasibility of wire ropes as lateral reinforcement at the boundary element of heavyweight concrete shear walls. The spacing of the wire ropes varied from 60 mm to 120 mm at an interval of 30 mm, which produces the volumetric index of the lateral reinforcement of 0.126~0.234. The wire ropes were applied as a external hoop and/or internal cross-tie. Five shear wall specimens were tested to failure under constant axial load and cyclic lateral loads. Test results showed that with the increase of the volumetric index of the lateral reinforcement, the ductility of shear walls tended to increase, whereas the variation of flexural capacity of walls was minimal. The flexural capacity of shear walls tested was slightly higher than predictions determined from ACI 318-11 procedure. The displacement ductility ratio of shear walls with wire ropes was higher than that of shear wall with the conventional mild bar at the same the volumetric index of the lateral reinforcement. In particular, the shear walls with wire rope index of 0.233 achieved the curvature ductility ratio of more than 16 required for high-ductility design.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.4
• /
• pp.501-509
• /
• 2010

A floating crane is a crane-mounted ship and is used to assemble or to transport heavy blocks in shipyards. In this paper, the static and dynamic response of a floating crane and a heavy block that are connected using elastic booms and wire ropes are described. The static and dynamic equations of surge, pitch, and heave for the system are derived on the basis of flexible multibody system dynamics. The equations of motion are fully coupled and highly nonlinear since they involve nonlinear mass matrices, elastic stiffness matrices, quadratic velocity vectors, and generalized external forces. A floating frame of reference and nodal coordinates are employed to model the boom as a flexible body. The nonlinear hydrostatic force, linear hydrodynamic force, wire-rope force, and mooring force are considered as the external forces. For numerical analysis, the Hilber-Hughes-Taylor method for implicit integration is used. The dynamic responses of the cargo are analyzed with respect to the results obtained by static and numerical analyses.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.1
• /
• pp.133-140
• /
• 2010

Five strengthened columns and an unstrengthened column were tested under constant axial load and cyclic lateral loads to examine the seismic performance of the unbounded strengthening procedure using wire ropes and T-plates. Main variables considered were the presence of mortar cover for strengthening steel element and anchorage method of T-plate. Test results clearly showed that T-plates having a proper anchorage contribute to transfer of applied moment as well as enhancement of ductility of reinforced concrete columns. However, T-plate not anchored fully into a column base can seldom transfer the externally applied moment, though it highly improves the ductility of column. The presence of mortar cover for strengthening steel elements is significantly effective in enhancing the initial stiffness and flexural capacity of the strengthened columns, but has an adversely effect on enhancing the ductility. The ultimate moment strength predicted from the extended section laminae method in better agreement with test results compared with predictions obtained using stress black specified in ACI 318-05.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.11 no.5
• /
• pp.131-139
• /
• 2001

In this paper, aerials gas pipeline vibrations due to the passing of vehicles have been measured, and peak values and characteristics of vibration were analyzed. In order to develop isolation system for gas pipeline, six cases with various support condition and hanging method were tested. The hanger used instead of wore rope isolated almost all vibrations transmitted from main beam. In the results of test, we could decrease response of vibration velocity from 49 % to 56 % and response of vertical vibration acceleration from 49 % to 60 %, because hanger instead of wire rope was used and rubber pads instead of wooden shield plates at support positions for Proofing horizontal vibration were used.

• Journal of the Korean Society of Safety
• /
• v.25 no.6
• /
• pp.70-74
• /
• 2010

For each strand of wirerope sling, the international standards, ISO-8794, EN-13414 specify that the splice shall have five series of load carrying tucks. At least three of the load carrying tucks shall be made with the whole strand. And, the breaking force of the splice shall not be less than 70% or 80% of that of rope. But, There are no prescriptions for splicing types against different efficiency of each splicing type being used many workplace. In this study, analysis the work limit load efficiency according to variation of number of tucks and splicing types by experimental method As a result, the number of tucks 3+2 had the highest breaking efficiency.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2000.12a
• /
• pp.217-220
• /
• 2000

현재, 선박용 로프제조에서 로프의 제조 공정은 수작업에 의해 행해지고 있어 작업의 효율화와 품질의 균질화를 위해서 최적의 장력제어가 필요하다. 본 연구의 목적은 와이어 로프 제조공정의 자동화이고 로프의 제조 공정에서 장치는 로프를 릴에 감아 올릴 필요성은 거의 없기 때문에 케이블을 풀어주는 속도와 로드셀에 의해 장력을 검출하고 장력을 발생하는 하드웨어 구성방법을 연구하는 것이다. 본 연구는 현수형 와이어 로프(Catenary Rope)의 동적 모델링을 작성한다. 이 시스템에 대하여 교류서보 전동기를 이용한 장력 발생장치를 모델링한다. 현수형 시스템의 장력 계측 장치는 하중 변환기(load cell)를 사용하고 수학적 모델링을 행한다. 장력 계측 장치에 관해서 스프링 저울을 이용해 출력을 비교 검토한 결과, 인장력을 계측하는 장치로서의 유효성을 확인하였다.