• 한국전산구조공학회논문집
• /
• 제22권3호
• /
• pp.267-275
• /
• 2009

이 논문에서는 복합재료 적층판 해석을 위해 등가단층요소와 부분-선형 층별 적층요소를 서로 연계시킨 결합요소를 제안하였다. 등가단층요소는 퇴화 쉘요소에 의해 정식화되었으며, 반면에 부분-선형 층별요소의 경우 면내변위는 부분적 선형변화로, 두께방향으로의 면외변위는 일정하다고 가정하였다. 제안된 유한요소모델은 p-수렴방식에 기초를 두고 있다. 변위장 보간을 위해 적분형 르장드르 다항식이, 수치적분을 수행하기 위해서는 가우스-로바토 적분을 각각 채택하였다. 이 연구에서는 주로 p-수렴 결합요소의 검증을 위해 다양한 형태의 유한요소 다중모델에 대해 안정된 수치해석값을 보여주는 지에 초점을 두었다. 채택한 예제는 정해를 쉽게 알고 있는 단순한 문제로 인장력을 받는 평판 또는 연직하중을 받는 캔틸레버보에 적용하여 제안된 요소의 성능을 평가하였다.

• Structural Engineering and Mechanics
• /
• 제34권6호
• /
• pp.719-738
• /
• 2010

The aim of this paper concerns with the nonlinear analysis of cable-stayed bridges including the vibration effect of cable stays. Two models for the cable stay system are built up in the study. One is the OECS (one element cable system) model in which one single element per cable stay is used and the other is MECS (multi-elements cable system) model, where multi-elements per cable stay are used. A finite element computation procedure has been set up for the nonlinear analysis of such kind of structures. For shape finding of the cable-stayed bridge with MECS model, an efficient computation procedure is presented by using the two-loop iteration method (equilibrium iteration and shape iteration) with help of the catenary function method to discretize each single cable stay. After the convergent initial shape of the bridge is found, further analysis can then be performed. The structural behaviors of cable-stayed bridges influenced by the cable lateral motion will be examined here detailedly, such as the static deflection, the natural frequencies and modes, and the dynamic responses induced by seismic loading. The results show that the MECS model offers the real shape of cable stays in the initial shape, and all the natural frequencies and modes of the bridge including global modes and local modes. The global mode of the bridge consists of coupled girder, tower and cable stays motion and is a coupled mode, while the local mode exhibits only the motion of cable stays and is uncoupled with girder and tower. The OECS model can only offers global mode of tower and girder without any motion of cable stays, because each cable stay is represented by a single straight cable (or truss) element. In the nonlinear seismic analysis, only the MECS model can offer the lateral displacement response of cable stays and the axial force variation in cable stays. The responses of towers and girders of the bridge determined by both OECS- and MECS-models have no great difference.