모멘트를 받는 플로팅 구조물 전이보 시스템 접합부의 거동

Abstract

A floating structure locates on the water space and generally, a ponton is constructed by reinforced concrete and an upper-structure by structural steels. The baseplate of a floating structure (connections of upper- structure and ponton) is influenced by lateral load caused by wind, tidal current, and waves as well as vertical load subjected by upper-structures.

This thesis is intended to study the behavior and performance of transfer-beam connection by conducting experiments and finite element analysis when they are subjected to moment under lateral load. A lateral load test and finite element analysis was conducted on test models with a different angle thickness and mock-up models with a different connection type. A finite element analysis was conducted by modelling the same shape as the specimen with ABAQUS, making experiment environment by applying appropriate options, and adding a friction factor on contact surface for variables. A load-displacement curve and a moment-rotation curve are analysed from the results of analysis and experiment.

The conclusion is as follows.

1) The behavior of the transfer-beam connection was modelled by type high-tension bolted connection and analyzed by applying the proper options of finite element analysis program “ABAQUS”.

2) The test model experimental result have shown that the thicker the angles are initial rotational stiffness and plastic rotational stiffness grow bigger. The Mock-up model experimental result have shown that the moment-carrying capacity of top and seat with double web angle connections increased by 1.41 times compared to top and seat angle connections.

3) Analysis result of the TSA-6 model has been shown to nearly match the experimental result. Moment and stiffness of the other analysis model with a thick angle thickness was higher than the experimental results. Such a difference in the analysis and experimental results is due to the occurrence of the slippage.

4) The finite element analysis results of each model have shown that the bigger the angle thickness is the more effects the friction coefficient has on structural capacity and behavior. Finite element analysis and regression analysis showed that the model are applied to a friction coefficient of 0.2 for a behavior similar to the experimental results.

5) The capacity and behavior of TSA-15 model was analyzed when it was under cyclic load by conducting a quasi-static analysis with ABAQUS. The results have shown that slip develops gradually along with plastic deformation unlike the results of pushover analysis and lateral load tests where slip occurred in the transfer section.