Stress distribution among sheathing-to-frame nails of timber shear walls related to different base connections: Experimental tests and numerical modelling

The performances of nailed timber shear walls subjected to in-plane horizontal actions are numerically investigated in the paper. In particular, it focuses on the different behavior that the vertical diaphragm may perform if the wall base steel devices are connected to the timber frame with or without the interposition of the sheathing. Nonlinear static analyses were performed and the dissipative capacity is concentrated in the connections among the components (nails, hold-down, angle brackets, stud-joist node), whose behavior is calibrated by means of experimental tests and numerical simulations on connections. The reliability of the numerical model was proved by comparing the numerical results with the findings of five full-scale experimental tests performed on shear walls subjected to in-plane horizontal cyclic loads. It emerged that the different arrangements of the base connections influence significantly the distribution of the shear among the sheathing nails and, when the base steel devices are applied with the sheathing interposed and/or the panels are nailed to a base timber plate, the force distribution among the fasteners significantly differs from those suggested by the analytical methods proposed in the literature.