This paper describes the development of a three-dimensional, non-linear finite-element model for evaluating the response of composite structural systems consisting of steel frames with reinforced-concrete infill walls subjected to a combination of gravity and in-plane lateral loading. Several sensitivity studies, taking into account both material characteristics and geometrical non-linearities were performed in order to investigate parameters such as the shear retention factors, Coulomb's coefficient for steel–concrete contacts and different load–slip relationships for modelling the shear behaviour of headed studs. Appropriate experimental data sourced from the literature were utilised to verify the proposed numerical model. A series of parametric studies was conducted to explore the effect of transverse and longitudinal confinement reinforcement, reinforcing bar diameter and steel strength. In order to investigate the composite interaction effect, several numerical models were developed, with emphasis on the configuration of shear connectors along the interface between the steel members and the reinforced-concrete infills. The analysis results demonstrated that the developed finite-element model captured and predicted the force–drift response of the system and revealed that the presence of shear connectors had a critical effect on the overall behaviour of the system.

This paper reports an investigation into the behaviour of wood-steel composite shear walls, consisting of strand laminated lumber boundary frames with infill steel plates. Recently it has been shown that wood-steel composite shear wall systems can offer various advantages over code-approved wood frame shear walls, including architectural flexibility. However, further research is needed so as to gain a better insight and understanding into the structural behaviour of this lateral load resisting system. On this basis, three-dimensional full-scale finite element models are developed and used to simulate the wood-steel composite shear wall with solid infill plates and with centrally-perforated infill plates. In this paper, firstly, a three-dimensional finite element model of wood-steel composite shear wall under monotonic loading. The numerical results were compared with experimental data and it was found that the model can predict the behaviour of wood-steel composite shear walls with reasonable precision. Using the verified model, a parametric study on wood-steel composite shear wall models with and without openings was performed. Critical parameters influencing the wood-steel composite shear walls behaviour such as the thickness of the steel plate and the opening ratio were investigated. The results of this parametric study provide useful information for the engineering application of wood-steel composite shear wall systems.

In recent years, hybrid steel-timber structures are seeing an increasing use in modern building construction at a competitive price. Cross-laminated timber (CLT) is a prefabricated multi-layer engineered panel wood product, manufactured by gluing layers of solid-sawn lumber at perpendicular angles. Their orientation results in excellent structural rigidity in both orthogonal directions. CLT construction materials are used not only for flooring systems and roof assemblies, but CLT infill shear walls are also gaining a lot of interest as a promising alternative for sustainable primary lateral load resistance systems. This paper extends the current research background on hybrid steel-timber structures. To achieve that, this work is conducted in such way as to explore the potentiality of incorporating CLT infill shear walls within steel framed structures with semi-rigid connections (STSW). In particular, a three-dimensional finite element model using the general-purpose finite ele-ment program ANSYS is generated herein to study the mechanical behaviour of a single-bay, two storey STSW system with semi-rigid connections. Analytical results show that the presence of CLT infill shear walls can significantly improve the performance of moment-resisting frame systems, for multi-storey buildings. Moreover, it is observed from the extended parametrical study that the STSW systems show better performance when an appropriate plastic moment ratio index is defined.

Behaviour and capacity of cross-laminated timber (CLT) infills built inside steel frames have been given increasing research attention in recent years. It is widely accepted that when the CLT wall panel is built in tight contact with the bounding steel frame to participate in the load sharing, its inherently large in-plane stiffness will attract additional forces to the frame area and change the behaviour of the hybrid system. If not designed properly, the structural integrity of both the infill and the frame will be compromised. It is thus crucial to accurately evaluate the contribution of the infill CLT wall panel to the stiffness and strength of the hybrid system. To that end, a finite element study was performed to investigate the frame-wall interaction effect on the behaviour of hybrid systems. The lateral stiffness, lateral load capacities and hysteretic characteristics of the hybrid systems with frictional and connected interfaces were investigated. The load-sharing effect between the CLT wall and the steel frame was studied. The numerical results showed that the connected models were very effective as the infill absorbed a substantial part of the lateral load, during the initial stages of loading.

In recent years, there has been a growing interest towards the use of a composite structural system consisting of steel frames with reinforced concrete walls (SRCWs) as an economical alternative within earthquake resistant wall systems. The SRCW system is classified as Composite Structural Systems Type 1 in EN 1998EN -1:2004. It has been shown that the SRCW system has the potential to be applicable as a lateral-resistance system for low-to-moderate rise buildings located in earthquake-prone regions as it has the potential to offer strength appropriate for resisting the lateral forces from earthquakes and stiffness adequate for controlling drift. Within the frame of this paper, analytical studies are conducted in order to obtain a better understanding of the SRCW system structural performance. Numerous three dimensional (3D) nonlinear Finite Element (FE) models have been developed using ANSYS software package. The detailed developed 3D FE models include the horizontal and vertical boundary steel elements, the discrete reinforcing bars, discrete stirrups as longitudinal and transverse confinement reinforcement, the shear connectors, the top and seat angles and the web angles including the bolts. Results and findings of this study are indicative of effectiveness of the headed studs geometry and material properties.