• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.189-1-190-1
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• 2008

A high temperature superconducting(HTS) power cable is available for high capacity current in normal condition. But resistance was appeared to operate unbalance load by thermal current characteristic. This characteristic of HTS power cable used to design for unstated condition. And than, It used to understand and analyze characteristic of power cable thermal and critical current. This study appeared that quench resistance reason from shield and former current rise to superconductor(SC) current. The resistance of SC occurred that the cable temperature rise to fault current after decreased critical current. The quench resistance of SC increased in temperature or decreased in critical current. So the quench resistance of SC correlated with resistance of both shield and former current. It need to sufficiently influenced the parameters of HTS cable design.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3314-3318
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• 2021

This paper presents a mode-matching analysis of the electromagnetic coupling between open cable trays in an indoor structure when an electric-line current is generated as an electromagnetic source. We validated the mode-matching method by comparing the mode-matching results with those computed from a commercial electromagnetic simulator and then investigated the strength of the electric-field coupled in a victim cable tray while varying the distances between cable trays and architectural surfaces. The results of this study provide geometrical information on the placement of open cable trays to avoid electromagnetic interference problems.

• Journal of Korean Association for Spatial Structures
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• v.8 no.6
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• pp.23-28
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• 2008

• Journal of Korean Association for Spatial Structures
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• v.5 no.1 s.15
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• pp.11-19
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• 2005

• Journal of Korean Association for Spatial Structures
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• v.16 no.3
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• pp.47-58
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• 2016

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.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2396-2406
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• 2021

The Pacific Earthquake Engineering Research (PEER) Center has been developing a performance-based earthquake engineering (PBEE) methodology, which is based on explicit determination of performance, e.g., monetary losses, in a probabilistic manner where uncertainties in earthquake ground motion, structural response, damage estimation, and losses are explicitly considered. To carry out the PEER PBEE procedure for a component of the nuclear power plant (NPP) such as the cable tray system, hazard curve and spectra were defined for two hazard levels of the ground motions, namely, operation basis earthquake, and safe shutdown earthquake. Accordingly, two sets of spectral compatible ground motions were selected for dynamic analysis of the cable tray system. In general, the PBEE analysis of the cable tray in NPP was introduced where the resulting floor motions from the time history analysis (THA) of the NPP structure should be used as the input motion to the cable tray. However, for simplicity, a finite element model of the cable tray was developed for THA under the effect of the selected ground motions. Based on the structural analysis results, fragility curves were generated in terms of specific engineering demand parameters. Loss analysis was performed considering monetary losses corresponding to the predefined damage states. Then, overall losses were evaluated for different damage groups using the PEER PBEE methodology.

• Computational Structural Engineering
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• v.3 no.3
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• pp.133-140
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• 1990

Analysis of cable structures is complex because their force - displacement relationships are highly nonlinear and also because large deformations introduce geometric nonlinearity. Therefore, we must take account their geometric nonlinearity in the analysis and find the equilibrated shape of cable structures. In this paper, to slove these problems, numerical procedures involving geometrical nonlinearity are introduced. They are applicable to general cable net, flexible transmission lines and suspended cable roof. These procedures are divided into two parts; one is to obtain the equilibrated shapes and stresses of the cable structures with uniform load by flexibility iteration method, the other is to analyse the equilibrated structures subjected to nodal external forces by nonlinear finite element method.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.982-996
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• 2016

In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

• Structural Engineering and Mechanics
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• v.52 no.5
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• pp.919-935
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• 2014

In this study, the control of the shape of pre-stressed cable structures and the effective control element were examined. The process of deriving the displacement control equations using the force method was explained, and the concurrent control scheme (CCS) and the sequence control scheme (SCS) were proposed. To explain the control scheme process, the quadrilateral cable net model was adopted and classified into a regular model and an irregular model for the analysis of the control results. In the control analysis of the regular model, the CCS and SCS analysis results proved reliable. For the SCS, the errors occur in the control stage and varied according to the control sequence. In the control analysis of the irregular model, the CCS analysis result also proved relatively reliable, and the SCS analysis result with the correction of errors in each stage was found nearly consistent with the target shape after the control. Finally, to investigate an effective control element, the Geiger cable dome was adopted. A set of non-redundant elements was evaluated in the reduced row echelon form of a coefficient matrix of control equations. Important elements for shape control were also evaluated using overlapping elements in the element sets, which were selected based on cable adjustments.

• Structural Engineering and Mechanics
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• v.42 no.2
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• pp.191-210
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• 2012

The Force Density Method (FDM) is a well known and extremely versatile tool in form finding of cable nets. In its linear formulation such method makes it possible to find all the possible equilibrium configurations of a net of cables having a certain given connectivity and given boundary conditions on the nodes. Each singular configuration corresponds to an assumed force density distribution. Its improvement as Non-Linear Force Density Method (NLFDM) introduces the possibility of imposing assigned relative distances among the nodes, the tensile level in the elements and/or their initial undeformed length. In this paper an Extended Force Density Method (EFDM) is proposed, which makes it possible to set conditions in terms of given fixed nodal reactions or, in other words, to fix the positions of a certain number of nodes and, at the same time, to impose the intensity of the reaction force. Through such extension, the (EFDM) enables us to deal with form findings problems of cable nets subjected to given constraints and, in particular, with mixed structures, made of cables and struts. The efficiency and the robustness of method are assessed through comparisons with other form finding techniques in dealing with characteristic applications to the prestress design of cable systems. As a further extension, the EFDM is applied to structures having some parts not yet geometrically defined, as can happen in designing new creative forms.