Theoretical, experimental and numerical study of aluminium-timber composite beams with screwed connections: Fid-Bau Portal

Theoretical, experimental and numerical study of aluminium-timber composite beams with screwed connections

Chybiński, Marcin / Polus, Łukasz

Highlights • The structural behaviour of ATC beams with screwed connections was investigated. • The behaviour of the connections was characterised and used in a FE analysis. • The adopted model adequately captured the response of the ATC joints and beams. • The behaviour of the connection may be modelled using zero-length springs. • The results calculated corresponded to the measured values.

Abstract The present study investigated the structural behaviour of aluminium-timber composite (ATC) beams. In the proposed ATC system, a timber slab was connected to aluminium girders by hexagon head wood screws. ATC beams are a relatively new civil engineering solution and their behaviour should be investigated to develop relevant methods for calculating their resistance. The authors examined the stiffness and the strength of the screwed connection used to join an aluminium girder with a timber slab. The slip moduli k0.4 and k0.6, and the peak load capacity per one connector were determined experimentally in two push-out tests. These parameters are necessary for designing ATC beams, because the behaviour of an ATC system is depended on the stiffness and the strength of its connections. Moreover, two bending tests were conducted on ATC beams to investigate their short-term behaviour, determine their bending resistance and capture the mode of failure, load-deflection and load-slip response. Based on the guidelines for timber and composite (steel-timber and steel-concrete) elements, the authors of this paper proposed the methods for calculating the bending resistance of the ATC beams, and the stiffness and strength of their screwed connections. The results obtained in the experimental tests were compared with the results from the analytical estimations. In addition, non-linear 3D finite element (FE) models of the tested composite beams and connections were developed and verified against the experimental results. The comparison between the experimental and numerical results demonstrated that the adopted 3D models were able to adequately capture the response of the ATC composite beams and their connections. These models may be used in further numerical analysis of ATC structures, e.g., to evaluate the impact of the number of the shear connectors on the load-bearing capacity of an ATC beam.