The performance of plywood-sheathed shear walls is determined at the plywood-to-timber joints. In joints with dowel-type fasteners, such as nails and screws, the fastener is fractured under reversed cyclic loading (e.g., seismic force), reducing the ductility of the joint. The fracture is caused by low-cycle fatigue due to the reversed cyclic bending of the fastener. Therefore, evaluating the fatigue life is important for estimating the ultimate displacement. The main objective of this study is to estimate the ultimate displacement of the joints and to enable load-displacement calculation of single shear joints under reversed cyclic displacement when bending fatigue failure of the fastener occurs. Single shear tests were conducted under different loading protocols, and the damage performances of the fasteners were determined by subjecting them to reversed cyclic bending tests. Based on the results, the failure lifetimes of joints with dowel-type fasteners were estimated. In addition, the fracture mechanism of these dowel-type fasteners was elucidated. CN50-type nails and wood screws with dimensions of 4.1 × 38 and 4.5 × 50 mm were used as fasteners. The single shear tests showed that the smaller the displacements per cycle, the lower are the ultimate displacement and ductilities of the joints. Moreover, load-displacement relationship up to fastener failure can be approximately estimated by combining the yield model and failure lifetime.

The load-deformation relationship of nail/wood screw joints of plywood-timber and plywood-sheathed shear wall was estimated considering the low cycle fatigue characteristics of fasteners. The estimation was conducted by modeling load-deformation relationship of joints and multiplying the reduction coefficient considering low cycle fatigue characteristics. Shear wall was evaluated by a finite element analysis using this model. The results of the constant-amplitude cyclic bending test for fastener were used to identify low cycle fatigue characteristics of fastener. When the experimental results observed fastener failure, the load-deformation relationship in joints and shear walls can be roughly estimated.

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