Design of Steel‐CLT Composite Beams: Bending Capacity and Stiffness

Abstract

The growing pressure to decarbonise the construction industry has increased interest in structural systems that combine timber with other materials. Steel frames combined with mass‐timber floors, such as cross‐laminated timber (CLT), have been investigated as low‐carbon and lightweight solutions with strong reuse potential. However, the composite action between steel and timber is often neglected. This article investigates the bending capacity and stiffness of steel–timber composite (STC) beams incorporating CLT floors. Bending capacity was assessed using both strain‐based and stress‐based approaches, with the latter being more suitable for practical applications. Three methods for evaluating the bending stiffness of STC beams were also examined, each with a different level of complexity. Several beam configurations are analysed, covering different spans, steel profiles, CLT panel sizes, and levels of shear connection efficiency, in order to compare the methods. Finite element models (FEM) were developed to evaluate the accuracy of the analytical approaches, incorporating non‐linear load–slip behaviour of novel shear connectors.