• Journal of Korean Association for Spatial Structures
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• v.3 no.3 s.9
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• pp.95-103
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• 2003

Frame is one of the most commonly used structural systems for the resistance of applied loads. Many researchers have recently conducted their studies to investigate the effect of several parameters such as the connection flexibility, boundary condition of each support, beam-to-column stiffness ratio. These parameters play important roles on the characteristic behavior of frames. A simplified spring model is proposed to obtain the story drifts of frames with various beam-to-column connection stiffnesses in this research. A point bracing system with adequate spring stiffness is also suggested to establish the relationship between the applied load and the resisting translational spring stiffness within the limit state of story drift.

• Journal of Korean Association for Spatial Structures
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• v.4 no.1 s.11
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• pp.69-75
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• 2004

In the construction of row-rise steel buildings, double angle connection can be considered as one of most effective connection types. Its connection flexibility depends mainly on several parameters such as angle thickness, bolt gage distance, and number of bolts. To establish the effect of the variation of the number of bolts on the moment-rotation relationship, three experimental tests have been conducted in this research. Based on the results of each experimental test, the rotational stiffness of each angle specimen can be calculated by performing regression analysis. Considering the results of regression analysis, we concluded that the more the number of bolts used in double angle connection, the higher the rotational stiffness as one can expected.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.629-639
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• 2004

A steel frame is one of the most commonly used structural systems due to its resistance to various types of applied loads. Many studies have been conducted to investigate the effects of several parameters, such as connection flexibility, the boundary condition of each support, and beam-to-column stiffness ratio, on the characteristic behavior of a frame. Based on the results of these studies, several design methods have been proposed. This research focused on the number of bolts on the rotational stiffness of a double-angle connection, and its effect on the story drift of a frame. To achieve these purposes, a simplified analytical model was proposed. Several experimental tests were also conducted to obtain the rotational connection stiffness of each double-angle connection.

• Journal of Navigation and Port Research
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• v.27 no.1
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• pp.63-70
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• 2003

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 have been studied using three types of connections for a four-bay eight-story frame. Three types of connections are used; 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 analysis.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1405-1421
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• 2015

Semi-rigid connections are the actual behavior of beam-to-column connections in steel frames. However, the behavior of semi-rigid connections is not taken into account for the simplicity in the conventional analysis and design of steel frames. A computer-based analysis and design has been studied for the three-dimensional steel frames with semi-rigid connections. The nonlinear analysis which includes the effects of the flexibility of connections is used for this study. It is designed according to the buckling and combined stress constraints under the present loading after the joint deformations and the member end forces of the space frame are determined by the stiffness matrix method. The semi-rigid connection type is limited to the top and bottom angles with a double web angle connection. The Frye-Morris polynomial model is used to describe the non-linear behavior of semi-rigid connections. Various design examples are presented to demonstrate the efficiency of the method. The results of design and analysis of unbraced semi-rigid frames are compared to the results of unbraced rigid frames under the same design requirements.

• Journal of Korean Association for Spatial Structures
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• v.6 no.1 s.19
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• pp.45-54
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• 2006

A steel frame is one of the most commonly used structural systems due to its resistance to various types of applied loads. Many studies have been conducted to investigate the effects of connection flexibility, support conditions, and beam-to-column stiffness ratio on the story drift of a frame. Based on the results of these studies, several design guides have been proposed. This research has been conducted to predict the actual behavior of a double angle connection, and to establish its effect on the story drift and the maximum allowable load of a steel frame. For these purposes, several experimental tests were conducted and a simplified analytical model was proposed. This simplified analytical model consists of four spring elements as well as a column member. In addition, a point bracing system was proposed to control the excessive story drift of an unbraced steel frame.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.78-91
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• 2024

Double steel plate concrete composite shear wall (SCSW) has been widely utilized in nuclear power plants and high-rise structures, and its shear connectors have a substantial impact on the seismic performance of SCSW. Therefore, in this study, the mechanical properties of SCSW with angle stiffening ribs as shear connections were parametrically examined for the reactor containment structure of nuclear power plants. The axial compression ratio of the SCSW, the spacing of the angle stiffening rib arrangement and the thickness of the angle stiffening rib steel plate were selected as the study parameters. Four finite element models were constructed by using the finite element program named ABAQUS to verify the experimental results of our team, and 13 finite element models were established to investigate the selected three parameters. Thus, the shear capacity, deformation capacity, ductility and energy dissipation capacity of SCSW were determined. The research results show that: compared with studs, using stiffened ribs as shear connectors can significantly enhance the mechanical properties of SCSW; When the axial compression ratio is 0.3-0.4, the seismic performance of SCSW can be maximized; with the lowering of stiffener gap, the shear bearing capacity is greatly enhanced, and when the gap is lowered to a specific distance, the shear bearing capacity has no major affect; in addition, increasing the thickness of stiffeners can significantly increase the shear capacity, ductility and energy dissipation capacity of SCSW. With the rise in the thickness of angle stiffening ribs, the improvement rate of each mechanical property index slows down. Finally, the shear bearing capacity calculation formula of SCSW with angle stiffening ribs as shear connectors is derived. The average error between the theoretical calculation formula and the finite element calculation results is 8% demonstrating that the theoretical formula is reliable. This study can provide reference for the design of SCSW.

• Journal of Korean Society of Steel Construction
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• v.19 no.2
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• pp.201-210
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• 2007

Double-angle connections should be designed with enough stiffness and strength to properly resist various applied loads. Therefore, structural engineers should be able to predict some influential variables and take their effects into account in design. This study was performed to establish the effects of the number of bolts and bolt gage distance on the stiffness and strength of a double-angle connection under tension. Six experimental tests were conducted to describe the effects of these variables by comparing load-displacement relationship curves. In addition, two prediction models were proposed to estimate the initial stiffness and the maximum allowable tensile load based on the results of experimental tests. In the development of these prediction models, the effect of prying action was considered.

• Steel and Composite Structures
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• v.10 no.1
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• pp.23-43
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• 2010

In this paper, a nonlinear model is developed using the component method in order to represent the response of steel connections under various loading conditions and temperature variations. The model is capable of depicting the behaviour of a number of typical connection types including endplate forms (extended and flush) and angle configurations (double web, top and seat, and combined top-seat-web) in both steel and composite framed structures. The implementation is undertaken within the finite element program ADAPTIC, which accounts for material and geometric nonlinearities. Verification of the proposed connection model is carried out by comparing analytical simulations with available results of isolated joint tests for the ambient case, and isolated joint as well as sub-frame tests for elevated temperature conditions. The findings illustrate the reliability and efficiency of the proposed model in capturing the stiffness and strength properties of connections, hence highlighting the adequacy of the component approach in simulating the overall joint behaviour at elevated temperature.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.11
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• pp.1473-1480
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• 1999

In the case of Impingement of plane moving shock wave over concave or convex double wedges (pseudo-stationary flow) and cylindrical walls (truly non-stationary flow), it Is expected that there are transitions from regular reflection to Mach reflection or vice versa In shock wave reflections. In these connections, it is necessary to verify the various of reflection process and transition angle for the reflection problems In double wedges, and to verify the transition angle, effects of curvature radius and initial wall angle on it for the reflection problems In cylindrical walls. Especially, we focused our attention to confirm the existence of hysteresis phenomenon induced by the different transition processes, and Neumann paradox, which is a small discrepancy between theoretical and experimental transition angles. Experiments were carried out by using the shock tube of $6{\times}6cm^2$, and high speed photographic technique consisted of delay unit, triggering system, light source of Xe lamp and so on was used for flow visualization.