Assessment of perforated steel beam-to-column connections subjected to cyclic loading

This paper presents a study of welded perforated beam-to-column connections, forming the so-called RWS systems. The effect of using non-standard novel web opening configurations of variable depths and positions is investigated. The ease of manufacturing process together with the improvements on the structural behaviour foreshadows the enhancements gained using these perforated members. It is concluded that using large perforations is an effective way of improving the behaviour of connections enhancing their ductility and their energy dissipation capacity. The connections with novel openings outperform the conventional ones; hence they can be suitably used in the aseismic design of steel frames

Earthquake-induced shear concentration in shear walls above transfer structures

Due to various architectural constraints and multi-functional requirements for modern buildings, combined structural forms, which typically include shear wall systems in higher zones and moment-resisting frames together with core walls in lower zones, are commonly used for these buildings. Transfer structures are often introduced to transfer the loads from higher to lower zones. Previous experimental and numerical studies have demonstrated that the exterior walls above the transfer structure are particularly vulnerable structural members under seismic loading. In this paper, a qualitative model is presented for simulating the shear concentration effect in exterior walls with consideration of the local deformations of transfer structures. A parametric study was carried out to validate the model and to quantify various factors which may influence the shear concentration effect. A shear concentration factor, which can measure the intensity of shear stress concentration in the exterior walls, is defined. Based on the numerical study, design principles are recommended to seismic engineers for minimizing the adverse shear concentration effect on exterior walls under seismic loads. Copyright © 2008 John Wiley & Sons, Ltd.postprin