This paper describes result of a study on safety against a fire of charging cable for mobile phone for vehicle. Combustion on the USB cable in the car was happened while driving. Gas coming from the burning USB cable could be a reason which can make a secondary car accident since the driver also can be embarrassed while driving. In order to prevent a secondary car accident connected on the road, to research a reason why USB cable can emit gas and be burned in charging. We did simulation test with abnormal fault condition for the electronic component on the board in the USB cable. So we get the result from abnormal fault condition simulation test, for instance, shorted test for output terminal of 8 pin switch, shorted test for chip resistor after thermal aging in the condition 25 ℃ , 93 % RH during 48 hours. To analysis the result of all test, Combustion on the USB cable was not the 8 pin but other electrical component such as a chip resistor. Therefore we guess that the reason for USB cable combustion in charging in a car was not 8 pin and a LED but another defective component.

Long-span marine bridges are generally designed as long-span bridges in order to secure the running route of the ship and reduce the cost and time of the bridge pier construction. In long-span bridges, the range of load resistance transmitted by the superstructure and cable is determined by the mast and foundation. In the other words, the range of designable span length would be determined by the mast and foundation condition. The floating bridge is a type in which the superstructure is supported by the force of buoyancy without the pier mounted on the seabed so that the buoyancy of the floating bridge is balanced by the dead load and buoyancy of the structure. As a technique to overcome the weakness of existing long span bridges, it is possible to consider the type of cable supported bridges with floating tower. In this study, according to the tendon arrangement and initial tension distribution, the static global performance of the long-span bridges with floating tower were evaluated.

Sometimes, it is impossible to install a sensor on a certain location of a structure due to the size of a structure or poor surrounding environments. Even if possible, sensors can be frequently malfunctioned or improperly operated due to lack of adequate maintenance. These kind of problems are solved by the virtual sensing methods in various engineering fields. Virtual sensing technology is a technology that can measure data even though there is no physical sensor. It is expected that this technology can be also applied to the construction field effectively. In this study, a virtual sensing technology based on ARX model is proposed. An ARX model is defined by using the simulated data through a structural analysis rather than by actually measured data. The ARX-based virtual sensing model can be applied to estimate unmeasured response using a transfer function that defines the relationship between two point data. In this study, a simulation and experimental study were carried out to examine the proposed virtual sensing method with a laboratory test on a cable-stayed model bridge. Acceleration measured at a girder is transformed to estimate a cable tension through the ARX model-based virtual sensing.

In this paper, an experimental study was carried out for vibration control of cable bridges with structurally flexible characteristics. For the experiment on vibration control, a model bridge was constructed by reducing the Seohae Grand Bridge and the shear type MR damper was designed using the wind load response measured at Seohae Grand Bridge. The shear type MR damper was installed in the vertical direction at the middle span of the model bridge, and dynamic modeling was performed using the power model. The tests of the vibration control were carried out by non-control, passive on/off control and Lyapunov control method on model bridge with scaled wind load response. The performance of the vibration control was evaluated by calculating absolute maximum displacement, RMS displacement, absolute maximum acceleration, RMS acceleration, and size of applied power using the response (displacement, acceleration, etc.) from the model bridge. As a result, the power model was effective in simulating the nonlinear behavior of the MR damper, and the Lyapunov control method using the MR damper was able to control the vibration of the structure and reduce the size of the power supply.

The objective of this study is to estimate the mechanical characteristics and nonlinear behaviors on the geometric nonlinear analysis of curved cable-membrane roof systems for long span lightweight roof structures. The weight of a cable-membrane roof dramatically can reduce, but the single layer cable-membrane roof systems are too flexible and difficult to achieve the required structural stiffness. A curved cable roof system with reverse curvature works more effectively as a load bearing system, the pretension of cables can easily increase the structural stiffness. The curved cable roof system can transmit vertical loads in up and downward direction, and work effectively as a load bearing structure to resists self-weights, snow and wind loads. The nonlinear behavior and mechanical characteristics of a cable roof system has greatly an affect by the sag and pretension. This paper is carried out analyzing and comparing the tensile forces and deflection of curved roof systems by vertical loads. The elements for analysis uses a tension only cable element and a triangular membrane element with 3 degree of freedom in each node. The authors will show that the curved cable-membrane roof system with reverse curvature is a very lightweight and small deformation roof for external loads.

The objective of this study is to analysis the mechanical characteristics on the geometric nonlinear behavior of radial cable roof systems for long span retractable cable roof structures. The retractable roof is designed as a full control system to overcome extreme outdoor environments such as extreme hot or cold weather, strong wind or sunlight, and the cable roof greatly can reduce roof weight compared to other rigid structural system. A retractable cable roof system is a type of structures in which the part of entire roof can be opened and closed. The radial cable roof is an effective structural system for large span retractable roofs, the outer perimeter of the roof is a fixed membrane roof and the middle part is a roof that can be opened and closed. The double arrangement cables of a radial cable truss roof system with reverse curvature works more effectively as a load bearing cables, the cable system can carry vertical load in up and downward direction. In this paper, to analyze the mechanical characteristics of a radial cable roof system with central posts, the authors will investigate the tensile forces of bearing cables, stabilized cables, ring cables, and the deflection of roof according to the height of the post or hub that affects the sag ratio of cable truss. The tensile forces of the cables and the deflection of the roof are compared for the cases when the retractable roof is closed and opened.

해저케이블은 두 가지 형태로 주로 사용이 되는데, 데이터통신을 전달하는데 사용되는 해저통신케이블과 전력을 송출하는데 사용되는 해저전력케이블이 있다. 둘 다 해저에 사용하도록 디자인 된 것이며, 해저통신케이블이 이 논문의 분석의 대상이다. 이 논문에서 해저케이블에 관련된 국제법 및 해저케이블의 설치에 관한 국가실행을 검토하고 국가실행이 국제법과 부합되는 범위를 검토한다. 이러한 방향에서 우선적으로 해저케이블의 설치에 관한 법적 체제를 분석한다. 법적 체제의 분석을 위하여 해저케이블을 규율하는 국제협약에 대하여 전반적으로 검토하며, 연안국의 관할권에 속하는 해역과 속하지 않는 해역에서 해저케이블의 설치에 관련하여 국가들이 규제하는 방식을 분석한다. 해저케이블운용에 대하여 연안국의 관할권수역과 관할권 바깥의 수역에서 연안국의 규제가 증가하고 있으며, 연안국이 해양활동, 심지어 케이블운용 같은 전통적으로 해양의 자유로서 인식되어온 활동에 대하여 연안국의 관할권을 확대하는 추세를 나타내고 있다. 또한 해저케이블 보호의 법적 체제를 검토하는데, 해저케이블의 보호는 두 가지 측면에서 검토한다. 우선, 케이블운용에 종사하는 선박을 다른 선박으로 부터 보호하는 방식을 살펴보며, 이후에 해양의 경합적 사용이나 의도적 가해 행위로 인한 피해나 파괴로부터 해저케이블을 보호하는 방식의 법적 문제점을 분석한다. 본 논문의 분석에 의하면 해저케이블의 보호에 관하여 연안국들의 규제가 충분하지 않은 것 같다. 국가들은 해양에서 경합적인 활동으로 인한 방해로부터 케이블선박을 보호하고 해양의 경합적인 사용에 의한 피해와 의도적인 가해 행위로 인한 피해에서 해저케이블을 보호하는데 필요한 조치를 자국의 법규로 제정하지 않은 경우가 많다. 해저케이블 및 케이블선박의 보호에 관한 국가들의 충분한 조치가 없다는 것은 해저케이블의 중요성에 대하여 국가들이 올바르게 인식하지 못하고 있는 이유도 있다. 이 논문에서 분석한 바와 같이 해저케이블의 보호를 위한 국제체제는 미흡한 점이 많다. 그래서 EEZ에서 해저케이블에 대한 의도적인 침해나 공격에 대응하기 위하여 개입하는 연안국의 관할권을 명확히 하기 위하여 특별한 고려가 필요하다. 해저케이블을 특정국가에게 등록하게 하고, 등록된 해저케이블의 등록국에게 해저케이블의 운용을 방해한 선박을 체포할 권리를 부여하는 방안이 있을 수 있다. 그러한 관할권이 해저케이블에 대한 피해를 해결하는데 유용할 수 있지만, 국가들은 현재까지 그러한 제도를 수락하는데 망설일 것 같다.

The objective of this study is to analysis the mechanical characteristics and nonlinear behaviors on the geometric nonlinear behavior of a cable spoke wheel roof system for long span lightweight roof structures. The weight of a cable spoke wheel roof dramatically can reduce and the cable roof system can easily make the required rigidity and shape by the sag ratio and pretension forces. Determining the pretension and initial sag of cable roof system is essential in a design process and the shape of roof is changed by pretension. The nonlinear behavior of flexible cable system has greatly an affect on the sag and pretension. This paper will be carried out analyzing and comparing the tensile forces and deflection of a cable spoke wheel system for the large span retractable roof, and analyzed to deflections and tensile forces by the post height of center hub. The double arrangement of a spoke wheel system with reverse curvature works more effectively as a load bearing system, the pretension can easily increase the structural stiffness. The cable truss system can carry vertical load in up and downward direction, and act effectively as load bearing elements.

The steel I-girder inserted circular steel pipe is a new structural cable-anchorage system that the circular guide pipe is connected and welded to the web of the I-girder for cable-stayed bridge. This guide pipe-anchor system has many merits of the structural and aesthetic performances. However, there has been little research into the behavior mechanism with respect to anchor angles and the strengthening methods against the sectional area reduction caused by the penetration of guide pipe. Therefore, this paper investigates an experimental behavior of the steel I-girder with circular steel tube which is fabricated 1/3 scale model as fundamental study to examine the flexural behavior and failure mode in the laboratory. Based on the comparison of test results and nonlinear FE analyses, it is found that FEM is suitable to estimate the stiffness of I-girder with circular tube in order to design the cable-stayed bridge.

Cable network system is a flexible lightweight structure which curved cables can transmit only tensile forces. The weight of cable roof dramatically can reduce when the length becomes large. The cable network system is too flexible, most cable systems are stabilized by pretension forces. The tensile force of cable system is greatly influenced by the sag ratio and pretension forces. Determining initial sag ratio of cable roof system is essential in a design process of cable structures. Final sag ratio and pretension depends on initial installed sag and on proper handling during installation. The design shape of cable system has an affect on the sag and pretension, and must be determined using well-defined design philosophy. This paper is carried out the comparative data of the deflection and tensile forces on the geometric non-linear analysis of cable network systems according to sag ratio. The study of cable network system is provided to technical informations for the design of a large span cable roof, analytical results are compared with the results of other researchers. Structural nonlinear analysis of systems having cable elements is relatively complex than other rigid structural systems because displacements are large as a reason of flexibility, initial prestress is applied to cables in order to increase the rigidity, and then divergence of nonlinear analysis occurs rather frequently. Therefore, cable network systems do not exhibit a typical nonlinear behavior, iterative method that can handle geometric nonlinearities are necessary.

Cable structures are lightweight structures of flexible type, cable members have only axial stiffness related to tension, they can carry neither bending nor compression. This study is the analysis of cable truss systems are composed of upper and low cables by connecting bracing cables, the structural principle is based on a tensegrity system by using bracing tension members, discontinuous compression members and continuous tension members. A hanging roof of cable truss system is too flexible against vertical loads, most cable members are stabilized by connecting the prestressed upper and lower cable by bracing cables. A cable truss roof system is formed by adding a set of cables with reverse curvature to the suspension cables. With the sets of cables having opposite curvature to each other, cable truss is able to carry vertical load in both upward and downward direction with equal effectiveness, and then a cable truss acts as load bearing elements by the assemble of ridge cables, valley cables and bracing cables. This paper will be shown the geometric non-linear analysis result of cable truss systems with various sag ratio for deflections and tensile forces, the analytical results are compared with the results of other researchers.

우리나라 서남해역에서 추진될 해상풍력 발전 단지에서 생산된 전기와 기존의 전력망과의 계통연계를 위해서는 해저케이블 설치가 필수적인 요소이다. 특히 해저케이블 설치에 대한 경제성, 시공성 및 안정성 확보를 위해서는 해저케이블 경과지와 해저케이블 보호공법 설계가 이루어져야한다. 본 논문에서는 1979년부터 2002년까지 한국해양과학기술원에서 구축한 장기 파랑산출자료와 제3세대 파랑모델인 SWAN(Simulating WAves Nearshore)을 이용하여 해상풍력단지가 조성될 해역에 대해 만조와 간조시 파랑시뮬레이션을 수행하여 해저케이블 경과지와 보호공법 설계를 위한 기초자료를 제공하고자 하였다. 연구결과, 서남해 해상풍력단지가 조성될 해역의 연평균 Hs는 1.03 m, Tz는 4.47s이고, 주파향은 북서(NW)와 남남서(SSW) 방향이다. NW에서 입사되는 조건(Hs: 7.0 m, Tp: 11.76s)에서 만조시 천해설계파랑 Hs의 분포는 약 4.0~5.0 m, 간조시에 약 2.0~3.0 m로 계산되었다. SSW에서 입사되는 조건(Hs: 5.84 m, Tp: 11.15s)에서 만조시 천해설계파랑 Hs의 분포는 약 3.5~4.5 m이고, 간조시에는 약 1.5~2.5 m로 계산되었다. 해저케이블 경과지 중 경도 UTM 249749~251349 구간 약 1.6 km에서는 NW로 입사되는 파랑의 영향이 크며, UTM 251549~267749 구간 약 16.2 km에서는 SSW로 입사되는 파랑의 영향이 지배적이다. 파랑집중 현상이 두드러지게 나타나는 해역은 위도와 하왕등도 사이 해역으로, 이 해역에서는 주변해역 보다 상대적으로 높은 파고를 나타내고 있다.

A series of tests was conducted for full-scale single-pylon asymmetric cable-stayed bridges using a system of multiple shaking tables. The 2-span bridge length was 28 m, and the pylon height was 10.2 m. 4 different base conditions were considered: the fixed condition, RB (rubber bearings), LRB (lead rubber bearings), and HDRB (high damping rubber bearings). Based on investigation of the seismic response, the accelerations and displacements in the axial direction of the isolated bridge were increased compared to non-isolated case. However, the strain of the pylon was decreased, because the major mode of the structure was changed to translation for the axial direction due to the dynamic mass. The response of the cable bridge could differ from the desired response according to the locations and characteristics of the seismic isolator. Therefore, caution is required in the design and prediction in regard to the location and behavior of the seismic isolator.

Compared with a strong axial rigidity due to large intial tension, cable has a weak laterally flexural rigidity. A variety of dynamic loads such as traffic loads and wind loads etc. cause the cables to vibrate significantly and affect the mechanical properties and the performance of cables. Therefore, vibration reduction design is an urgent task to control the vibration of cable-supported bridges. Because a various kind of dampers have shown to reduce the amplitude and duration time of vibration of cable from measured date in field test, damper can be considered that it is effective device significantly to reduce the amplitude and duration time in vibration of cable. Vibration characteristics of cable can change according to manufacturing method and type of established form, and damper has been designed according to distribution of natural frequencies and vibration modes. In this study, numerical analysis is used to show the reduction effects of vibrations and present the design of damper for vibration reduction of cable.

This paper presents using Newton-Raphson method calibration for planar cable robot. In cable robot there are three big error issue which are geometric error and and modeling error and non-geometric error, in this paper we just focus on first two issue. Using MATLAB simulation we found minimum of 8 pose we have to use in calibration equation and the initial vale can decrease of the iteration.