• Steel and Composite Structures
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• v.5 no.2_3
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• pp.141-158
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• 2005

The new version of Code for Design of Steel Structures (GB50017-2003) and other design standards in China were released over the last two years. Comparing with the previous version (GBJ17-88), many clauses covering the connection design have been revised. A number of additional provisions are supplemented to specify the design requirements for beam-column moment connections, as well as gusset plates for truss joints. In this paper, a summary on the design rules on connections specified in the current Chinese code is presented, and relevant commentary and background information is provided whenever appropriate. The design criteria governing weld and bolt resistance is examined and reviewed. Moreover, several issues such as detailing requirements for stiffeners and end-plate connections are discussed.

• Journal of the Korean Society of Safety
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• v.17 no.2
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• pp.76-84
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• 2002

The seismic behaviors of steel moment connections with different structural characteristics are investigated. The rupture index, which represents the fracture potential, is adopted to study the effect of concrete slab and the relative strength between the coin the beam, and Panel zone on the ductility of connections. The results show that the presence of slab increases the beam strength, imposes constraint near the beam top flange, and consequently, induces concentrated deformation near the beam access hall, which reduces the ductility of the connection. The total deformation capacity of the connection depends not only on the beam but also on the column and panel zone. Therefore, the detrimental slab effects and the relative strength should be considered in the seismic design of the connection.

• Steel and Composite Structures
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• v.2 no.4
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• pp.277-296
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• 2002

A research investigation of single bolt lap-plate connection load-deformation behavior is presented. Each important characteristic of this behavior is evaluated and two methods for analytically approximating the behavior are developed and presented. The first of these methods is a component method in which the behavior of the connection is modeled as a combination of the behavior of the parts. The second method utilizes a number of parametric relationships that relate the connection parameters to coefficients of two non-linear continuous analytical curves. The test results from four independent experimental programs that investigated the behavior of single bolt lap-plate connections are used in the development and verification of these methods.

• Steel and Composite Structures
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• v.6 no.2
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• pp.139-157
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• 2006

In this paper, a cyclic mechanical model is presented to simulate the behaviour of top and seat with web angle beam-to-column connections. The introduced mechanical model is compared with Eurocode 3 Annex J, its extension, and with experimental data. To have a better insight regarding the actual response of the joints, available results of the experiments, carried out on full-scale top and seat angle joints under monotonic and cyclic loading, are first considered. Subsequently, a finite element model of the test setup is developed. The application of the proposed model, its comparisons with the experimental curves and with the Eurocode 3 Annex J and with its modification, clearly show the excellent quality of the model proposed.

• Steel and Composite Structures
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• v.6 no.1
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• pp.71-85
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• 2006

This paper presents the results of a series of tests carried out on cold-formed steel rectangular hollow and concrete infilled beam to column connections and frames. A stub column was chosen such that overall buckling does not influence the connection behaviour. The beam chosen was a short-span cantilever with a concentrated load applied at the free end. The beam was connected to the columns along the strong and weak axes of columns and these connections were tested to failure. Twelve experiments were conducted on cold-formed steel direct welded tubular beam to column connections and twelve experiments on connections with concrete infilled column subjected to monotonic loading. In all the experiments conducted, the stiffness of the connection, the ductility characteristics and the moment rotation behaviour were studied. The dominant mode of failure in hollow section connections was chord face yielding and not weld failure. Provision of concrete infill increases the stiffness and the ultimate moment carrying capacity substantially, irrespective of the axis of loading of the column. Weld failure and bearing failure due to transverse compression occurred in connections with concrete infilled columns. Six single-bay two storied frames both with and without concrete infill, and columns loaded along the major and minor axes were tested to failure. Concentrated load was applied at the midspan of first floor beam. The change in behaviour of the frame due to provision of infill in the column and in the entire frame was compared with hollow frames. Failure of the weld at the junction of the beam occurred for frames with infilled columns. Design expressions are suggested for the yielding of the column face in hollow sections and bearing failure in infilled columns which closely predicted the experimental failure loads.

• Steel and Composite Structures
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• v.20 no.5
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• pp.1155-1171
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• 2016

Post-tensioned (PT) steel moment resisting frames (MRFs) with semi-rigid connections (SRC) can be used to control the hysteretic energy demands and to reduce the maximum inter-story drift (${\gamma}$). In this study the seismic behavior of steel MRFs with PT connections is estimated by incremental nonlinear dynamic analysis in terms of dissipated hysteretic energy ($E_H$) demands. For this aim, five PT steel MRFs are subjected to 30 long duration earthquake ground motions recorded on soft soil sites. To assess the energy dissipated in the frames with PT connections, a new expression is proposed for the hysteretic behavior of semi-rigid connections validated by experimental tests. The performance was estimated not only for the global $E_H$ demands in the steel frames; but also for, the distribution and demands of hysteretic energy in beams, columns and connections considering several levels of deformation. The results show that $E_H$ varies with ${\gamma}$, and that most of $E_H$ is dissipated by the connections. It is observed in all the cases a log-normal distribution of $E_H$ through the building height. The largest demand of $E_H$ occurs between 0.25 and 0.5 of the height. Finally, an equation is proposed to calculate the distribution of $E_H$ in terms of the normalized height of the stories (h/H) and the inter-story drift.

• Steel and Composite Structures
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• v.23 no.4
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• pp.409-420
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• 2017

This paper theoretically studies the cyclic behavior of hybrid connections between steel coupling beams and concrete shear walls with embedded steel columns. Finite element models of connections with long and short embedded steel columns are built in ABAQUS and validated against the test results in the companion paper. Parametric studies are carried out using the validated FE model to determine the key influencing factors on the load-bearing capacity of connections. A close-form solution of the load-bearing capacity of connections is proposed by considering the contributions from the compressive strength of concrete at the interface between the embedded beam and concrete, shear yielding of column web in the tensile region, and shear capacity of column web and concrete in joint zone. The results show that the bond slip between embedded steel members and concrete should be considered which can be simulated by defining contact boundary conditions. It is found that the loadbearing capacity of connections strongly depends on the section height, flange width and web thickness of the embedded column. The accuracy of the proposed calculation method is validated against test results and also verified against FE results (with differences within 10%). It is recommended that embedded steel columns should be placed along the entire height of shear walls to facilitate construction and enhance the ductility. The thickness and section height of embedded columns should be increased to enhance the load-bearing capacity of connections. The stirrups in the joint zone should be strengthened and embedded columns with very small section height should be avoided.

• Steel and Composite Structures
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• v.53 no.2
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• pp.227-241
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• 2024

Advancements in additive manufacturing technology, notably for its efficiency, accuracy, automation, and streamlined procedures, are increasingly relevant in civil engineering. This study evaluates the mechanical properties of 316L stainless steel bolted connections fabricated using Powder Bed Fusion (PBF) additive manufacturing. Eleven single-lap bolted connection specimens were tested under monotonic loading to assess the influence of various factors, including plate thickness, manufacturing direction, bolt end and edge distances, and bolt quantity, on the connections' anti-sliding and shear capacities. Material tests conducted prior to the connection tests revealed that PBF-manufactured stainless steel plates possess higher yield and ultimate strength, as well as greater elongation capacity, compared to traditional stainless steel plates. The connection tests indicated that the anti-sliding coefficient values range from 0.348 to 0.698, aligning with current standards for stainless steel bolted connections. Three distinct failure modes were identified: net section failure in the stainless-steel plate, bolt shear failure, and plate shear failure. It was determined that existing standards for anti-sliding capacity may not be entirely applicable to PBF-manufactured connections. Therefore, a modified model for the anti-sliding capacity of these connections is proposed. Additionally, a more accurate formula for calculating their shear capacity, which addresses the oversight of friction forces in current standards, is introduced.

• Steel and Composite Structures
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• v.23 no.3
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• pp.351-362
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• 2017

This paper presents an experimental study on the behavior of composite floor slab comprised by a new steel sheet and concrete slab. The strength of composite slabs depends mainly on the strength of the connection between the steel sheet and concrete, which is denoted by longitudinal shear strength. The composite slabs have three main failures modes, failure by bending, vertical shear failure and longitudinal shear failure. These modes are based on the load versus deflection curves that are obtained in bending tests. The longitudinal shear failure is brittle due to the mechanical connection was not capable of transferring the shear force until the failure by bending occurs. The vertical shear failure is observed in slabs with short span, large heights and high concentrated loads subjected near the supports. In order to analyze the behavior of the composite slab with a new steel sheet, six bending tests were undertaken aiming to provide information on their longitudinal shear strength, and to assess the failure mechanisms of the proposed connections. Two groups of slabs were tested, one with 3000 mm in length and other with 1500 mm in length. The tested composite slabs showed satisfactory composite behavior and longitudinal shear resistance, as good as well, the analysis confirmed that the developed sheet is suitable for use in composite structures without damage to the global behavior.

• Steel and Composite Structures
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• v.7 no.5
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• pp.377-390
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• 2007

In the design of concrete filled composite columns, it is assumed that the load transfer between the steel tube and concrete core has to be achieved by the natural bond. However, it is important to investigate the mechanisms of shear transfer due to the possibility of steel-concrete interface separation. This paper deals with the contribution of headed stud bolt shear connectors and angles to improve the shear resistance of the steel-concrete interface using push-out tests. In order to determine the influence of the shear connectors, altogether three specimens of concrete filled composite column were tested: one without mechanical shear connectors, one with four stud bolt shear connectors and one with four angles. The experimental results showed the mechanisms of shear transfer and also the contribution of the angles and stud bolts to the shear resistance and the force transfer capacity.