Fig. 3From: Estimation of failure lifetime in plywood-to-timber joints with nails and screws under cyclic loadingEstimation curve of load–displacement relationship. Here, F is the frictional force, Py is the yield strength, Pmax is the maximum load, δy is the yield displacement, δmax is the displacement at maximum load, δu-nf is the ultimate displacement when the fastener does not fracture, K is the initial stiffness, and K′ is the secondary stiffnessBack to article page