New modeling for moment–rotation behavior of bolted endplate connections

A new exponential model to depict the moment–rotation (M–θM–θ) relationship of Bolted Endplate Connections (BEC) is proposed. The proposed model represents an approach to the prediction of M–θM–θ curves, taking into account the possible failure modes and the deformation characteristics of the connection elements. The presented model has three physical parameters, along with two curve-fitted factors. These physical parameters are generated from dimensional details of the connection, as well as the material properties. By employing simplified connection behavioral models to estimate the connection M–θM–θ behavior, analytical expressions for evaluating major connection parameters, such as initial stiffness and ultimate moment, are derived. The M–θM–θ curves obtained by the model are compared with published connection tests and 3D FEM research. The model yields acceptable results in good agreement with actual connection behavior. Besides, comparison between the presented model and other existing equations, in prediction of the derived BEC’s M–θM–θ curve, shows the reasonably accurate results of the proposed model.