• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1618-1621
• /
• 2003

Wire rope is widely used to handle heavy materials. The material used to build the wire rope lock is mostly aluminum which is expensive. In this study, wire rope lock made of cheeper material with better performance is developed.

• 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.

• 한국안전학회지
• /
• 제27권2호
• /
• pp.78-83
• /
• 2012

This is a study to confirm how to improve and substitute the existing re-bar with other material such as a fiber rope, especially super fiber rope having much more strong tensile strength. 6(b) different fiber rope reinforced beam with a section of $20{\times}30cm$ have been made and tasted as variables designed in the study. The larger diameter of fiber rope, the more capacity of the beam, even though fiber reinforced beam are increased with ten(10)percent, each. Lower capacity of fiber-reinforced beam than normal RC beam has been analyzed theoretically and empirically, based on a lot of experiences of the same size beam test. Fiber rope-reinforced concrete beam does not have sufficient capacity than RC beam due to insufficient bonding capacity of fiber rope in concrete. It leads to decrease beam bearing capacity and crack around lower center of the beam. Therefore, bonding reinforcement of fiber rope beam such as pinning a triangles steel pin in each knot of fiber rope contributes to improving bearing capacity of fiber rope reinforcing beam.

• Journal of Information Processing Systems
• /
• 제19권6호
• /
• pp.745-755
• /
• 2023

The wire rope is an indispensable production machinery in coal mines. It is the main force-bearing equipment of the underground traction system. Accurate detection of wire rope defects and positions exerts an exceedingly crucial role in safe production. The existing defect detection solutions exhibit some deficiencies pertaining to the flexibility, accuracy and real-time performance of wire rope defect detection. To solve the aforementioned problems, this study utilizes the camera to sample the wire rope before the well entry, and proposes an object based on YOLOv5. The surface small-defect detection model realizes the accurate detection of small defects outside the wire rope. The transfer learning method is also introduced to enhance the model accuracy of small sample training. Herein, the enhanced YOLOv5 algorithm effectively enhances the accuracy of target detection and solves the defect detection problem of wire rope utilized in mine, and somewhat avoids accidents occasioned by wire rope damage. After a large number of experiments, it is revealed that in the task of wire rope defect detection, the average correctness rate and the average accuracy rate of the model are significantly enhanced with those before the modification, and that the detection speed can be maintained at a real-time level.

• 한국강구조학회 논문집
• /
• 제22권2호
• /
• pp.151-160
• /
• 2010

최근 기상이변으로 인한 겨울철 폭설로 농가 시설물 중의 하나인 비닐하우스의 붕괴사고가 빈번히 발생하여 농가의 피해가 증가되고 있다. 하지만 이에 대한 정부의 대책이 미약하여 매년 붕괴사고가 일어난다. 프레임 붕괴의 주된 이유는 폭설시 저항할 수 있는 휨내력이 부족하기 때문이다. 본 연구에서는 현재 이용되는 비닐하우스에 인장타이로 보강한 실험연구를 수행하였다. 비닐하우스의 스팬은 6.5m이고, 단면은 두 가지 종류(${\phi}25.4{\times}1.5$, ${\phi}31.8{\times}1.5$)를 사용하였다. 비닐하우스의 곡선 보와 직선 기둥 연결부에 임시적인 인장타이로 스틸와이어와 로프를 이용하여 보강하였다. 프리텐션을 인장타이에 적용시켰고, 적설하중을 등가의 수직하중으로 파괴할 때까지 적용하였다. 무보강과 로프 보강을 비교한 결과 로프 보강의 붕괴하중이 10∼45% 증가하였고 무보강과 스틸와이어 보강을 비교한 결과 스틸와이어 보강의 붕괴하중이 58~73% 증가하였다. 강도와 관련해서는 비교적으로 스틸와이어가 효과적이나, 연결부 및 프리텐션 적용이 로프보다 복잡하고 어려우므로 로프가 더 효율적인 것으로 판단된다.

• 대한기계학회논문집A
• /
• 제27권11호
• /
• pp.1873-1880
• /
• 2003

The sliding wear characteristics of the crane sheave were investigated using a pin on disk rig tester. The experiment was conducted using a high carbon steel wire that was upper material, also carbon steel castings that was disk material. There are various operating conditions in this work. At the room temperature, we carried out the wear test under a grease lubrication and dry condition. The results of wear test showed that an annealed-casted have lower, also the wear curves are linearly increased with increasing of sliding distance. For the specific wear rate of annealed-casted, the wear resistance was increased with decreasing diameter of wire. The wear of a wire and a disk have a different mechanism, the one is the abrasive wear due to fatigue wear under lubrication, another is the adhesion wear under dry condition.

• Structural Engineering and Mechanics
• /
• 제18권5호
• /
• pp.591-607
• /
• 2004

The substance of the use of the derived non-linear creep constitutive equations under variable stress levels (see first part of the paper, Kmet 2004) is explained and the strategy of their application is outlined using the results of one-step creep tests of the steel spiral strand rope as an example. In order to investigate the creep strain increments of cables an experimental set-up was originally designed and a series of tests were carried out. Attention is turned to the individual main steps in the production and application procedure, i.e., to the one-step creep tests, definition of loading history, determination of the kernel functions, selection and definition of constitutive equation and to the comparison of the resulting values considering the product and the additive forms of the approximation of the kernel functions. To this purpose, the parametrical study is performed and the results are presented. The constitutive equations of non-linear creep of cable under variable stress history offer a strong tool for the real simulation of stochastic variable load history and prediction of realistic time-dependent response (current deflection and stress configuration) of structures with cable elements. By means of suitable stress combination and its gradual repeating various loads and times effects can be modelled.

• 한국산업융합학회 논문집
• /
• 제27권3호
• /
• pp.555-561
• /
• 2024

This paper derives material properties of steel bars that simulate the distribution of stress and strain of prestressed tendons used in Prestressed concrete(PSC) girders and presents an optimal material model. ABAQUS software was used to establish the 3D solid model of the PSC girder and strand wire rope for a PS(Prestressed) tendon. Then the model of steel wire rope was imported into the Isight interface plugin directly through the ABAQUS and the Data Matching. In ABAQUS, the contact pairs were established, the models were meshed, the constraints were applied to solve the finite element model and an axial tension of 0.5m/s was loaded to analyze the stress and deformation distributions in the normal working range of the PS strand wire rope. In Data Matching, classical experimental data is fitted to the optimal material properties through finite element analysis and multi-objective optimization. The results show that the steel bar with optimal material properties presents a similar linear area and stress distribution with the PS tendon.

• 콘크리트학회논문집
• /
• 제20권2호
• /
• pp.221-229
• /
• 2008

와이어로프와 T형 강판을 이용한 개선된 비부착형 기둥보강 공법이 개발되었다. 제시된 절차에 따라 보강된 기둥 8개와 동일한 조건의 무보강 기둥 1개가 중심 축하중 하에서 실험되었다. 주요 변수는 와이어로프 체적비와 T 강판의 플랜지 폭 및 배치 형상이다. 실험된 기둥의 축하중 내력과 연성비는 각각 ACI 318-05의 예측값과 Chung et al.에 의해 수행된 일반 띠기둥의 실험 결과와 비교되었다. 게다가 와이어로프와 T 강판으로 구속된 콘크리트의 응력-변형률 관계를 평가하기 위한 모델이 제시되었다. 실험 결과로부터 기둥의 축하중 내력과 연성은 와이어로프의 체적비와 T 강판의 플랜지 폭의 증가와 함께 증가하였다. 특히 동일 횡보강근 지수에서 와이어로프 체적비가 0.0039 이상일 때 보강된 기둥의 연성비는 띠철근 기둥에 비해 현저히 높았다. 개발된 보강기술에 의해 구속된 콘크리트의 응력-변형률 관계 모델이 제시되었다. 예측된 응력-변형률 관계는 실험 결과와 잘 일치하였다.

• 한국항해항만학회지
• /
• 제42권6호
• /
• pp.388-394
• /
• 2018

선박이 계류삭을 이용하여 부두에 접안하는 경우, 과도한 선박 속력은 계류삭이 절단되는 사고를 야기할 수 있다. 이러한 계류삭의 파단 사고를 방지하기 위해서는 계류삭 파단 방지에 선박의 한계치 접안 속력을 알아야 한다. 본 연구의 목적은 계류삭 파단을 방지하기 위한 선박의 한계치 접안 속력 추정에 있다. 본 연구의 핵심은 선박의 속력을 모르는 경우 선박제원과 계류삭 제원을 이용하여 접안 시 한계치 접근 속력을 추정하는 방법이다. 본 연구에서는 선체저항과 계류삭의 탄성력 등에 관한 이론을 바탕으로 한계치 접안 속력의 추정 방법과 절차를 제안하였다. 135K LNG 선박과 IWRC, $6{\times}36$의 강선 계류삭을 대상으로 한계치 접안 속력을 추정한 결과, 추정한 접안 속력으로 접안하는 경우 계류삭이 파단이 되지 않는 것으로 분석되어 제안한 방법이 유효함을 알았다. 본 연구에서 제안한 방법은 실제 선박에서 계류삭 파단을 방지하는데 기여할 수 있을 것으로 기대된다.