Experimental tests and numerical modelling of timber joints with tube fasteners

In this paper, some cyclic experimental tests on beam-column timber joints with expanded tube fasteners are reported and discussed. The connections are reinforced with Densified Veneer Wood. A good energy dissipative capacity is observed for each joint tested, making them particularly suited for use in earthquake-prone regions. Hence, a numerical model for the cyclic behaviour of these joints is presented and validated against the experimental data. The proposed modelling approach represents a beam-column joint schematized with shell elements for the wooden parts and non-linear one-degree-of-freedom springs for each tube employed in the connections. The model is able to accurately reproduce the hysteretic behaviour of the joint, minimising the differences in total potential energy between numerical curves and experimental results. This numerical tool has been used to model some representative plane moment-transmitting frame structures, varying the number of bays and storeys. After an estimation of each frame configuration capacity using a push-over analyses, such models were finally employed to estimate the behaviour factor using an Incremental Dynamic Analysis. Such analyses were performed with sets of accelerograms, spectrum-consistent with a chosen design spectrum. The carried-out analyses lead to an estimation of the behaviour factor for such structures that confirms their highly-dissipative behaviour.