파랑하중을 고려한 반강접 접합부의 비선형해석

Abstract

Beam-to-column connections of steel frames are assumed fully rigid or pinned connection for convenience in analysis and design, but because all beam-to-column connections have moment translation and rotation resistance, we need to understand correctly the behavior of semi-rigid connections.

In general, the semi-rigid connections are preferred for low rise structure. If semi-rigid connections are used for superstructures of very large floating structures(VLFS), the number of rigid connections can be reduced and more economical construction will be possible.

In this study, considering service load and wave load in VLFS, the applicability of mixed use of rigid and semi-rigid connections has been studied using three combinations of connections for a four-bay eight-story frame. Three types of connections are used

1.As the amplitude of wave loads is small, the difference of displacement and moment responses in 3 type structural systems is large. However, as the amplitude wave loads is large, the difference of responses decreases, because the responses of wave loads are dominant.

2.The analysis results of Case3 with TSD semi-rigid connections in lower floors show that the additional moment due to wave loads can be reduced in lower floors, but the lateral displacements become large.

3.The extended end plate connections with high stiffness have an advantage for displacement control compared to TSD connections. The steel tubular column with square external-diaphragm connections shows similar behavior as TSD connections.

4.In case of truss bracing for reducing lateral displacements, the difference of responses of various structural systems is not great. Through benefits of reducing moment and displacement responses, the structural system as semi-rigid connections with truss bracing is efficient for superstructure of VLFS.

5.The results of inelastic analysis of 3 type structural systems with semi-rigid connections show that the ultimate load coefficient of Case3 is smaller and the inelastic behaviors of structural systems are different especially in plastic regions.

top- and seat-angle connections with double web-angle(TSD), extended end plate connections, steel tubular column with square external-diaphragm connections. ABAQUS(Finite element analysis program) is used for conducting second order elastic and inelastic analysis.

The conclusions of this study are as follows