Empirical Model of the Moment-Rotation Curve of Beam-to-Beam Bolted Flush Endplate Connections

Based on the current knowledge of steel moment connections, an empirical predictive three-parameter exponential model to depict the moment-rotation (M-theta) relationship of bolted flush endplate beam-to-beam (BFEB) connections is presented in this paper. The exponential model has three control parameters. For deriving the parameters of the model in terms of the connection description, the results of a wide parametric finite-element (FE) study including 468 analyses of BFEB connections is used. For the parameters of the model such as the intercept constant moment and yielding rotation, a power equation that takes into account the key geometrical properties of the connection detail is proposed by means of regression analyses of three-dimensional (3D) FE method (FEM) results. The statistical analyses on the prediction of all model parameters for all 468 cases are presented. Also, the major parameters of the M-theta curve, such as the elastic stiffness and strain hardening stiffness are also expressed as a combination of the model parameters. The moment-rotation curves obtained by the model are compared with various published connection tests and the 3D FEM research. The model yields acceptable results and is in good agreement with actual connection behavior. DOI: 10.1061/(ASCE)ST.1943-541X.0000597. (C) 2013 American Society of Civil Engineers.