• 제목/요약/키워드: cable stiffness

검색결과 190건 처리시간 0.023초

사장교의 지진 응답 제어를 위한 납고무 받침의 설계 기준 제안 (Guidelines of Designing Lead Rubber Bearing for a Cable-Stayed Bridge In Control Seismic Response)

  • 이성진;박규식;김춘호;이인원
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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    • pp.509-516
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    • 2003
  • In tile design of base isolation system for building and short-span bridge, shift of the natural period of the structure is main objective. But, most long-span bridges such as a cable-stayed bridges have a number of long-period modes due to their flexibility and small structural damping. thus the design concept of base isolation system for building and short-span brigde may be difficult to use directly to these structures. However, the effectiveness of LRB for cable-stayed bridges is indicated by Ali and Abdel-Ghaffar. In this study, the design procedure and guidelines of LRB for a seismically excited cable-stayed bridge are investigated. The design properties of LRB are chosen that the design index(DI) is minimized or little changed for variation of properties. This result show that the stiffer rubber and bigger lead core size are need to cable-stayed bridges. And the seismic performance of designed LRB is also investigated. The consequences show that the perforamnce of designed LRB is better than that of Naeim-Kelly mettled designning LRB for general building structures. Moreover, the design properties of LRB are researched to several diffrent dominant frequency of earthquake. The results present that the plastic and elastic stiffness of LRB are affected by the dominant frequency of earthquake.

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Study of structural parameters on the aerodynamic stability of three-tower suspension bridge

  • Zhang, Xin-Jun
    • Wind and Structures
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    • 제13권5호
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    • pp.471-485
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    • 2010
  • In comparison with the common two-tower suspension bridge, due to the lack of effective longitudinal restraint of the center tower, the three-tower suspension bridge becomes a structural system with greater flexibility, and more susceptible to the wind action. By taking a three-tower suspension bridge-the Taizhou Bridge over the Yangtze River with two main spans of 1080 m as example, effects of structural parameters including the cable sag to span ratio, the side to main span ratio, the deck's dead load, the deck's bearing system, longitudinal structural form of the center tower and the cable system on the aerodynamic stability of the bridge are investigated numerically by 3D nonlinear aerodynamic stability analysis, the favorable structural system of three-tower suspension bridge with good wind stability is discussed. The results show that good aerodynamic stability can be obtained for three-tower suspension bridge as the cable sag to span ratio is assumed ranging from 1/10 to 1/11, the central buckle are provided between main cables and the deck at midpoint of main spans, the longitudinal bending stiffness of the center tower is strengthened, and the spatial cable system or double cable system is employed.

분산분석을 이용한 스트랜드의 축강성 예측에 관한 연구 (A Study on the Axial Stiffness Prediction of Stand Using Analysis of Variance)

  • 박용대;양원호;허성필;성기득
    • 대한기계학회논문집A
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    • 제25권1호
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    • pp.127-134
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    • 2001
  • Wire ropes are widely used in cable car, suspension bridge and elevator, etc. and composed of single or multi-layer strands. It is difficult to find out the characteristics of a strand or wire rope because of complicated geometry and contact condition. In this study, the axial stiffness is evaluated using finite element method and reliable finite element analysis model is presented, taking into consideration the convergence on the length. The axial stiffness predictive equation of a strand is developed using analysis of variance, which can be applicable for characterizing the relationship between load and displacement when the strand configuration is determined.

단면감소에 따른 사장케이블의 2-자유도 근사모델의 고유진동수 분포 (Distribution of Natural Frequency of 2-DOF Approximate Model of Stay Cable to Reduction of Area)

  • 조양희;이현철
    • 한국구조물진단유지관리공학회 논문집
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    • 제18권6호
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    • pp.147-154
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    • 2014
  • 사장교 케이블의 손상은 사장교 전체의 안전에 가장 큰 영향을 주는 요인이 되므로 케이블의 손상에 대한 유지관리를 필수적으로 해야한다. 이러한 유지관리의 대표적인 방법으로 케이블의 고유진동수변화을 추적하는 방법이 있다. 지금까지 케이블의 고유진동수는 진동법에 의해 횡방향 진동으로 추정하여 왔으며 시스템인식기법은 반복법에 의한 민감도방정식으로 축방향강성을 추정하나 새그의 영향으로 종방향운동에 대한 고유진동수의 분포에 대한 연구가 필요하다. 이 연구에서는 종방향운동에 의한 고유진동수를 이용하여 손상을 추정함으로써, 종방향운동의 신뢰성을 향상시키는 새로운 방법을 제안하였다. 이 방법의 적용결과를 근사해인 유한요소해석결과와 비교하여 유사한 결과를 얻음으로써 제안된 방법의 신뢰성을 검증하였다. 따라서, 케이블손상과 고유진동수와의 관계를 분석한 결과는 손상률이 증가할수록 고유진동수는 낮게 나타났다. 따라서 케이블의 실측 고유진동수를 알 때 케이블손상과 고유진동수와의 관계식을 통해 케이블의 손상정도를 추정할 수 있으므로 케이블의 효율적인 유지관리가 가능하게 된다.

Static and free vibration analysis of shallow sagging inclined cables

  • Li, Zhi-Jiang;Li, Peng;He, Zeng;Cao, Ping
    • Structural Engineering and Mechanics
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    • 제45권2호
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    • pp.145-157
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    • 2013
  • Based on link-model, we conducted a static analysis and computation of a three-span suspended cable structure in the present paper, and obtained the static configuration and tension distribution of the cable. Using the link and beam model based on finite element method, we analyzed the vibration modal of three-span suspended cable structure, and compared with the results obtained from ANSYS using link and beam element. The vibration modals of shallow sagging inclined cables calculated from proposed method agrees well with ANSYS results, which validates the proposed method. As a result, the influence of bend stiffness on in-plane natural frequencies is much greater than that on out-of-plane natural frequencies of inclined cables.

Stiffness of hybrid systems with and without pre-stressing

  • Miljanovic, Sladana;Zlatar, Muhamed
    • Coupled systems mechanics
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    • 제9권2호
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    • pp.147-161
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    • 2020
  • Constructive merging of "basic" systems of different behavior creates hybrid systems. In doing so, the structural elements are grouped according to the behavior in carrying the load into a geometric order that provides sufficient load and structure functionality and optimization of the material consumption. Applicable in all materializations and logical geometric forms is a transparent system suitable for the optimization of load-bearing structures. Research by individual authors gave insight into suitable system constellations from the aspect of load capacity and the approximatemethod of estimating the participation of partialstiffnesswithin the rigidity ofthe hybrid system. The obtained terms will continue to be the basisfor our own research of the influence of variable parameters on the behavior of hybrid systemsformed of glued laminated girder and cable of different geometric shapes. Previous research has shown that by applying the strut-type hybrid systems can increase the load capacity and reduce the deformability ofthe free girder.The implemented parametric analysis pointsto the basic parameterin the behavior of these systems-the rigidity ofindividual elements and the overallstiffnessofthe system.The basic idea ofpre-stressing is that, in the load system or individual load-bearing element, prior to application of the exploitation load, artificially challenge the forcesthatshould optimize the finalsystembehaviorin the overall load. Pre-stressing is possible only if the supporting system orsystem's element possesssufficientstrength orstiffness, orreaction to the imposed forces of pre-stressing. In this paper will be presented own research of the relationship of partial stiffness of strut-type hybrid systemsofdifferentgeometric forms.Conducted parametric analysisofhybridsystemswithandwithoutpre-stressing, and on the example of the glulam-steel strut-type hybrid system under realistic conditions of change in the moisture content ofthe wooden girder,resulted in accurate expressions and diagramssuitable for application in practice.

기하형상에 따른 강사장교의 안정성에 관한 연구 (Effect of Geometric Shapes on Stability of Steel Cable-stayed Bridges)

  • 김승준;한승룡;김종민;조선규;강영종
    • 한국강구조학회 논문집
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    • 제23권1호
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    • pp.13-27
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    • 2011
  • 본 연구에서는 기하학적 비선형 해석을 통해 완성계 사장교의 주요한 좌굴 거동 특성을 규명하였다. 본 해석 연구에서는 케이블의 자중에 의한 새그효과, 주탑 및 거더의 보-기둥 효과, 그리고 대변위 효과 등의 주요한 기하학적 비선형성이 직접적인 비선형 해석을 통해 고려되었다. 주탑과 거더는 비선형 프레임 요소로 모델링 되었고, 케이블은 비선형 등가 트러스 요소로 모델링 되었다. 차량하중으로 가정된 활하중이 고려되었는데, 활하중 해석 전에 고정하중을 합리적으로 고려하기 위해 초기 형상 해석이 수행되었다. 작용하는 활하중 형태에 따른 주요한 비선형 반응을 케이블 배치 형식에 따라 비교 하였고, 이 후 좌굴 안정성에 큰 영향을 미치는 활하중 형태에 대해 케이블의 배치 형식, 주탑과 거더 간 강성비, 케이블의 단면적, 케이블의 단수 등의 기하학적 특성이 좌굴 모드 및 임계 하중 계수의 변화에 미치는 영향을 규명하였다.

집중 이동하중을 받는 사장교의 휨 및 비틈 거동에 관한 연구 (A Study on the Bending and Torsional Behaviors of Cable-Stayed Bridges under a Concentrated Moving Load)

  • 장승필;임성순;주석범
    • 대한토목학회논문집
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    • 제9권3호
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    • pp.1-12
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    • 1989
  • 사장교는 경간이 크기 때문에 발생하는 대변형 효과, 케이블의 현수 작용, 그리고 축력으로 인한 휨 강성 변화 등으로 비선형 거동이 나타난다. 사장교의 동적 거동은 구조물 안정성 검사를 위한 중요한 요소가 된다. 특히, 편재 이동하중이 작용하는 경우, 연직 변위와 비틂 변위는 복합될 뿐만 아니라 단면 좌우의 케이블 축력 변화도 중요한 동적 특성을 나타낸다. 본 연구에서는 편재 이동하중이 작용하는 사장교의 해석을 위한 이론적 연구와 유한 요소법을 제시하였고 이동 하중의 속도변화와 편심량의 크기에 따라 케이블의 장력과 절점 변위에 대한 동적 거동을 규명하였다. 본 연구에서 수행한 해석 결과에 따르면, 편재 이동 하중을 받는 사장교의 해석에서는 주형의 비틂과 이로 인한 케이블 축력 증가도 고려해야 할 것으로 사료된다.

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케이블-기반 개폐식 지붕의 모니터링을 위한 영상 전송 장치 개발 (Development of Video Transmission Device for Monitoring of a Cable-Based Retractable Roof)

  • 안수홍;손수덕;이승재;강주원
    • 한국공간구조학회논문집
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    • 제19권4호
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    • pp.103-110
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    • 2019
  • The cable-based retractable membrane roof makes it impossible to maintain its shape and stiffness during driving process, unlike the hard-type retractable roof. Consequently, monitoring using a relatively simple wireless video transmission device is required. However, since video data has a bigger transmission rating than other monitoring data in terms of the structure velocity or acceleration, there is a need to develop transmission device that is easy to install and entails low maintenance cost. This paper studies on a real-time video transmission system for monitoring the cable-based retractable membrane roof while driving. A video transfer software, using the mobile network, is designed and the embedded system is constructed. Ultimately, the data transmission server is tested. Connecting a trolley to the system allows testing of the validity and efficiency of the developed system through the video data transmitted in the driving process. Result of the test shows that the developed system enables multi-device data transfer with monitoring via the mobile network.

불균일 단면을 갖는 저장력 예인케이블에 관한 수치해석적 연구 (A STUDY ON NUMERICAL SIMULATION OF TOWED LOW-TENSION CABLE WITH NONUNIFORM CHARACTERISTICS)

  • 정동호;박한일
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2002년도 춘계학술대회 논문집
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    • pp.161-166
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    • 2002
  • Low-tension cables have been increasingly used in recent years due to deep-sea developments and the advent of synthetic cables. In the case of low-tension cables, large displacements may happen due to relatively small restoring forces of tension and thus the effects of fluid and geometric non-linearities become predominant. In this study, three-dimensional (3-D) dynamic behavior of a towed low-tension cable with non-uniform characteristics is numerically analyzed by considering fluid and geometric non-linearities and bending stiffness. A Fortran program is developed by employing a finite difference method. In the algorithm, an implicit time integration and Newton-Raphson iteration are adopted. For the calculation of huge size of matrices, block tri-diagonal matrix method is applied, which is much faster than the well-known Gauss-Jordan method in two point boundary value problems. Some case studies are carried out and the results of numerical simulations are compared with a in-house program of WHOI Cable with good agreements.

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