Modeling Load-Displacement Hysteresis Relationship of a Single-Shear Nail Connection

Abstract

A finite element based single-shear nail-connection model has been developed based on an existing computer model which idealizes dowel-type wood connection as an elastoplastic beam surrounded by a compression-only wood medium. Both the new and base models predict the lateral hysteresis response of the connection considering the nonlinear material behavior of the surrounding wood medium and the connector and the formation of gap between the wood and the connector which leads to pinched-hysteresis loops during cyclic loading. The base model assumes the compressive strength of the wood medium decreases after the connections reach certain lateral displacements. The new model assumes that the strength of the wood medium does not decrease at any compressive displacement. Instead, it is assumed that the loss of load carrying capability of the nail connection is primarily caused by the decrease in the vertical contact length of the wood medium against the nail. The new model has been validated using reversed-cyclic nail connection test data in terms of stiffness, strength, and energy dissipation.