Sheathing nail bending-yield stress: Effect on cyclic performance of wood shear walls

This study investigated the effects of sheathing nail bending-yield stress (f(yb)) on connection properties and shear wall performance under cyclic loading. Four sets of nails were specially manufactured with average f(yb) of 87, 115, 145, and 241 ksi. Nail bending-yield stress and the hysteretic behavior of single-nail lateral connections were determined. The parameters of the lateral nail tests were used in a numerical model to predict shear wall performance and hysteretic parameters. The competency of the numerical model was assessed by full-scale cyclic tests of shear walls framed with Douglas-fir lumber and sheathed with oriented strandboard (OSB). The parameters of the shear wall model were used in another program to predict shear wall performance for a suite of seismic ground motions. The single-nail connection tests and wall model computations suggested that increased f(yb) of the sheathing nails should lead to improved wall stiffness and capacity. In both single-nail lateral connection and shear wall tests, the probability of nonductile failure modes increased as f(yb) increased. The peak capacity of the walls increased as f(yb) of the sheathing nails increased up to 145 ksi, but wall initial stiffness, displacement at peak capacity, and energy dissipation were not significantly affected by f(yb). Sheathing nail f(yb) greater than 145 ksi did not enhance the overall cyclic behavior of wood shear walls.