Analytical Assessment of Effects of Cover Plates on Improvement the Seismic Nonlinear Behavior of Moment Link to Column Connections in Eccentrically Braced Frames

Many codes and regulations for designing of steel structures the same as 10th part of Iranian national buildings code don’t offer any solution link-to-column connection in eccentric braced frames. In eccentrically braced frames (EBF), required ductility and a major part of absorption and energy depreciation is done by link to column connection. The ability of link in absorb and depreciate energy is depended on specification and geometric details. So design of link-to-column connection in resistant frames to earthquake with eccentrically braced frames remains an unsolved problem. This paper is discussing about the effect of adding cover plates on improving the seismic behavior of not reinforced moment connection of the link beam and preparing the ductility demand of connection by finite elements method. In this paper the model fracture recognition is introduced with adopting the experimental results with the maximum plastic strain index. Welded link-to-column connections have the potential to fracture in the wing of link beam, before adequate rotation. So three types of cover plates are assessed to delay the fracture of connection. The result was that the triangular cover plates have the best performance.The result was that the triangular cover plates have the best performance.The result was that the triangular cover plates have the best performance.