• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.25 no.3
• /
• pp.195-202
• /
• 2012

Two nonlinear frame elements taking into account geometric nonlinearity is presented and compared based on the Lagrangian co-rotational formulation. The first frame element is believed to be geometrically-exact because not only tangent stiffness matrices is exactly evaluated including stiffness matrices due to initial deformation but also total member forces are directly determined from total deformations in the deformed state. Particularly two exact tangent stiffness matrices based on total Lagrangian and updated Lagrangian formulation, respectively, are verified to be identical. In the second frame element, the deformed curved shape is regarded as the polygon and current flexural deformations in iteration process are neglected in evaluating tangent stiffness matrices and total member forces. Two numerical examples are given to demonstrate the accuracy and the good performance of the first frame element compared with the second element. Furthermore it is shown that the first frame element can be used in tracing nonlinear behaviors of cable members.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.06a
• /
• pp.341-343
• /
• 2012

농어촌민들에게 안정적인 전력공급을 위해 낙후도서에 해저케이블 공사 중인 곳이 많다. 특히 선박통항량이 많은 무역항내 해저케이블 공사는 준설이 수반되기 때문에 안전위해요소가 많다. 안전위해요소를 분석하고 이를 해결할 수 있는 방안에 대해서 고찰해 본다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.1 no.1
• /
• pp.93-101
• /
• 1989

A geometrically nonlinear cable finite element is presented to use in the static or dynamic modeling of offshore and onshore structures such as guyed tower, tension leg platform or mooring buoy, submarine cable, cable-stayed bridge, suspension bridge, cable roof and so on. The cable finite element is derived directly from the compatibility equations and flexibility matrix of elastic catenary cable theory for the arbitary plane loading and geome try. A general and virsatile computer program has been developed to perform the analyses of cable member itself or cable guyed or suspened structures, in which Newmark-$\beta$ method is used to obtain a time domain solution and Newton-Raphson iteration method is used to solve the nonlinear system of compatibility equations of cable and algebraic static or dynamic equations at each time step. The results from the static and dynamic analysis of a cable member by the computer program are summarized and presented.

• Journal of Korean Society of Steel Construction
• /
• v.12 no.6
• /
• pp.661-670
• /
• 2000

To investigate the characteristics of the dynamic response of long-span cable-stayed bridges due to various dynamic loadings likes moving traffic loads, two different 3-D cable-stayed bridge models are considered in this study. Two models are exactly the same in structural configurations but different in finite element discretization. Modal analysis is conducted using the deformed dead-load tangent stiffness matrix. A new concept was presented by using divided a cable into several elements in order to study the effect of the cable vibration (both in-plane and swinging) on the overall bridge dynamics. Futhermore case of asymmetric traffic loading clustered in one direction are also considered to study the torsional response of the bridge. The result of this study demonstrates the importance of cable vibration on the overall bridge dynamics.

• Journal of Korean Society of Steel Construction
• /
• v.18 no.6
• /
• pp.727-735
• /
• 2006

In this paper, a geometric nonlinear analysis procedure of the beam-column element including multi-noded cable element in extension of companion paper (Kim et al., 2005) is presented. First, a stiffness matrix was derived about the beam-column element that considers the second effect of the initial force supposing the curved shape at each time-step, with Hermitian polynomials as the shape function. Second, the multi-noded cable element was also subjected to the tangent stiffness matrix. To verify the geometric nonlinearity of this newly developed multi-noded cable-truss element, the Innovative Prestressed Support (IPS) system using this theory was analysed by geometric nonlinear method and the results were compared with those produced by linear analysis.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.5
• /
• pp.115-121
• /
• 2006

This paper deals with the influence of behavior of a variety of cable elements on the limit strength of steel cable-stayed bridges. The softening plastic-hinge model, which is represented in this study for the limit strength evaluation of the example bridge, considers both geometric and material nonlinearites. Geometric nonlinearity of beam-column members are accounted by using stability function, and material nonlinearity - by using CRC tangent modulus and parabolic function. Cable sag effect is considered for cable members. The result of this study shows that the limit strength of the example bridge using the equivalent of elasticity for truss straight elements is smaller than those using the cable or the catenary elements.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.2087_2088
• /
• 2009

최근 도심지 전력수요의 증가로 송전선로 건설의 필요성이 증대되고 있으나, 가공송전선로가 가지고 있는 한계 때문에 지중송전선로의 건설이 증대되고 있는 추세이다. 이러한 상황에서 지중 및 가공을 포함하는 거시적인 관점에서 지락 및 단락과 같은 고장시의 대전류 현상에 대한 연구는 어느 정도 시도된 바가 있으나, 지중케이블 시스템 자체에 미치는 영향에 대해서는 그 연구가 미비한 것이 현실이다. 특히 단락고장의 경우 고장전류의 크기도 크지만 고장전류 발생에 따른 전자력을 동반하게 되어 케이블 및 접속함, 각종 금구류에 전기적, 기계적인 스트레스를 야기할 수 있다. 따라서 본 논문에서는 최근 발생한 단락고장 상황을 고려하여 전자력에 의한 케이블의 거동특성을 확인하기 위해 154kV OF케이블 3상단락 실증시험을 시행하였고, 실증시험시 촬영된 고속카메라 영상을 이용한 변위분석 결과와 유한요소법을 이용하여 계산된 케이블의 변위 특성을 비교 분석하여 유한요소법을 이용한 계산방법이 케이블 거동특성 분석에 적합한지 그 실효성을 검증하고자 한다.

• Journal of Korean Association for Spatial Structures
• /
• v.8 no.5
• /
• pp.95-105
• /
• 2008

The objective of this study is find out the stressed condition, slipped direction and slipped dimension when some elements of cable-membrane structures are slipped from it's initially designed coordinates by external loads as wind or non uniform load and so on. In order to search the slipped behaviors of cable-membrane structures, a ALE finite element formulation is introduced. In these procedures, a stiffness matrix related with ALE concept is formulated and a FE analysis program for cable-membrane structures with slipped elements is developed.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.2 no.2
• /
• pp.95-104
• /
• 1998

The dynamic behavior of the marine cable is essentially nonlinear and dominated by geometric nonlinearity. Furthermore, fluid drag force makes the problem more complex and difficult. Therefore, it has certain limitations to obtain the dynamic behavior of the marine cable by analytical method. The purpose of this paper is to apply the elastic catenary cable element to the problem of under water cable including the hydrodynamic effects of fluids. The static and dynamic formulations for the three-dimensional elastic catenary coble under water effects are derived and the finite element analysis procedures are presented. In the analysis, the hydrodynamic forces are modeled by modified Morison equation. A comparison of the results obtained using present method with previously published results showed the validity of present method. The dynamic behavior of the marine cable subjected to current is investigated using present method and it can be illustrated that the dynamic behavior of the marine cable subjected to current varies with the incident angle of the current and inclined angle of the cable.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.564-565
• /
• 2011

본 연구는 154 kV, 345 kV급 초고압 케이블의 수직구간 활락 안전성에 대한 평가를 진행하였다. 안전성에 대한 평가는 유한요소해석법을 이용하여 진행하였으며, 당사에서 제작한 케이블 및 클리트에 대하여 케이블의 자중과 발열에 따른 제품 내부의 응력과 케이블의 변형량에 초점을 맞추어 비교 분석하였다. 해석 결과, 하중 및 발열에 대해 재료의 인장강도 측면에서 충분한 안전율을 가지고 있는 것으로 나타났으며, 변위 해석 또한 최대 변위 발생부가 최대 응력 발생부와 관계없는 케이블 끝단에서 나타나는 것으로 볼 때, 재료 건전성 측면에서 안전한 것으로 해석되었다. 본 연구는 향후 경사지나 수직구간의 포설 설계시 해석적 방법으로 포설 안전성을 확보하는데 기여할 수 있을 것으로 사료된다.