Equivalent parameterized beam model for nailed connections in low-rise residential buildings

Increased frequency and intensity of coastal storms has renewed interest in the structural performance of coastal low-rise residential homes. Post hazard surveys indicate connections that form the load path from sheathing to framing to foundation play a pivotal role in the failure modes of these non-engineered structures. Nonlinear spring elements are a common means of modeling nailed connections for structural analysis based on experimentally observed behavior. Due to complex connection behavior, three independent springs are usually defined to consider 3D translational displacements. This common approach may introduce error in large displacement analyses due to independently defined directional spring properties. After a brief discussion of issues encountered with nonlinear spring element connection modeling schemes, an equivalent parameterized beam connection model is proposed to characterize softening-type connection behavior. Comparison analyses between the equivalent parameterized beam connector (EPBC) and equivalent nonlinear spring connector (ENSC) are carried out using 1D and 2D single element examples as well as 3D panel models. This new connection modeling scheme could greatly reduce meshing efforts in large models and provide more accurate solutions in critical areas of the structure such as corners and edges by coupling the axial and transverse connection responses.