Modification of Moment Connection of I-Beam to Double-I Built-Up Column by Reinforcing Column Cover Plate

Traditional moment connections of I-beam to double-I built-up column have some problems. They are the stress concentration, brittle fracture of the welds and semi-rigid behavior of the connection. To upgrade the connection behavior, it is proposed to replace parts of the column cover plate, situated in critical areas where the beam flanges (or flange plates) connect to the column cover plate, by thicker and larger plates. To investigate the cyclic behavior of the proposed connection, a series of nonlinear finite element analysis were carried out on different models. Results indicate that the modified connection has such a strength and ductility that can be used in special moment frames. Its stiffness is also in the range of a fully restrained connection.