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This paper presents the results from an experimental study on the actual behavior of header end-plate connections. To better understand the hysteretic behavior of these connections in terms of the stiffness and the strength, sixteen specimens were considered and subjected to cyclic loads. The effect of some parameters such as thickness of the header end-plate, depth of the connection and the number of bolt rows on the behavior of header end-plate connections has been investigated by the help of experimental tests and finite element (FE) analyses. The moment-rotation relations of the connections governed by three parameters such as initial stiffness, moment capacity and rotation capacity were obtained. Results revealed that the moment capacity increases with the increase in end-plate thickness and depth of connection. However, for the equal connection depth, increasing the number of bolt rows has not influenced the connection behavior in any noticeable way.

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It is clear that semi‐rigid frames exhibit completely non‐linear behaviour under cyclic loading due to gradual yielding of connection components. The current study presents the experimental results from the test of a semi‐rigid frame specimen, comprising a single storey and one bay, and the analysis results obtained from a finite element model of the specimen. In this study, semi‐rigid joints with header plates are used for beam‐tocolumn connections. The initial stiffness and moment‐carrying capacity of the connection, designed as a semi‐rigid and partial strength connection type, were determined in accordance with Eurocode 3. In the modelling of the semi‐rigid beam‐to‐column connection behaviour, four‐parameter non‐linear representation of the moment—rotation curve obtained using the Ramberg‐Osgood formula was employed. Loading of the test specimen consisted of quasi‐static cycles with displacement control. The cyclic response of the specimen is characterized by a stable hysteretic behaviour. When comparing the envelope of the hysteresis loops from the cyclic test of the specimen with the pushover curve achieved by non‐linear finite element analysis, the model gives a good prediction of the ultimate strength and initial stiffness of the frame.

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Eccentrically braced frame (EBF) system is one of the most effective lateral loads resisting systems for steel structures. In these systems, links are designed in such a way that they yield in shear not only to provide high ductility and rigidity but also to provide a high energy dissipation capacity. In particular, as the internal forces to be considered for the design of the members outside of the links must be calculated with the amplification factor based on the yielding of the links, the magnitude of the internal forces may become so large that they may not be met by the adjacent members. Therefore, it is challenging to develop an economic design for adjacent members and connections because of the high level of design loads obtained by the amplification factor. This paper studies the effect of the perforation arrangement in the web of shear link beams in eccentrically braced frames. Both experimental and numerical investigation were conducted to demonstrate the effectiveness of the link beam with slotted perforations in the web portion. Seven equivalent isolated link beam specimens with various slot-hole patterns were tested under quasi-static cyclic loading. The results of the study indicate that using slot-holes in the web portion reduces the link shear capacity significantly. The results also show that the failure mechanism of reduced link sections was controlled by fracture at end of the slot-holes and inelastic rotation capacities were varying between 0.025 rad and 0.065 rad depending on the slot-hole patterns.