Experimental study of the shear performance of H-shaped aluminum-timber composite connections

Abstract

Aluminum alloy has significant advantages in reducing self-weight and improving the corrosion resistance compared with steel. The performance of the interface between timber and H-shaped aluminum alloy beams is the key to designing aluminum-timber composite beams. Twelve groups of double-shear tests were conducted in this paper to investigate the influences of glulam strength, the type and size of connectors, and the row number of connectors on shear capacity, and the failure modes of connections were evaluated. The results have shown that, compared with the specimens connected by screws, the bolt heads of the specimens connected by bolts tended to cause local crushing failure of the glulam. There is negligible difference between the shear capacities of aluminum-timber and steel-timber connection when connected by single-row screws. For the group effect of the screws, the reduction of shear capacity of aluminum-timber connections is slightly higher than that of steel-timber connections when connected by multi-row screws. The shear capacity of aluminum-timber connections with multi-row screws needs to be reduced when one plastic hinge appears in the screws (failure mode II). It does not need to be reduced when two plastic hinges appear in the screws (failure mode III), and the theoretical value has a large safety margin. The length-to-diameter ratio λ is the main factor affecting the failure modes of the screws, and the coefficient λy is introduced to discriminate the failure modes.