عنوان مقاله [English]
Using continuity plates in the balance of the tensile and compressive beam's flanges in the box column is for satisfying stiffness and strength criteria according to terms of the 2800 code and the tenth issue of national building regulations. Since in box columns due to section closure, lack of vision and inappropriate viewing angles performance of the continuity plates inside the column has many problems, continuity plates removed from the box column and rigidity of connection provide by stiffeners from outside welded the joint and their Installation is more simple than continuity plates. For this purpose connectivity models without continuity plates, connection with continuity plates, connection with trapezoidal external stiffener, connection with internal stiffener including networks of horizontal bar and the proposed new connection which includes of the external stiffeners, concrete and networks of horizontal bar by ANSYS software modeling and analyzed. Graph of force – displacement of models is drawn based on monotonic and cyclic analyzes and on their have been determined rigidity, strength, ductility, energy dissipation as well as the location of plastic hinges in every connection. The analysis determined that the proposed new connection with the acquisition of rigidity 96.18, ductility 7.04, ultimate strength 89.45 ton and transferred the plastic hinge into the area far from connection, therefor it is a good alternative for continuity plates.