Analytical study of Eccentrically Braced Frames with steel plate in corners

Eccentrically Braced Frames have been developed because of combining desirable behavior of dissipating earthquake energy of moment frame and good lateral stiffness of braced frames. Plastic behavior of link beam has a major role in energy dissipation, and in most cases, this energy dissipation lead to extreme damage in link beam. Reconstructing of this type of the structures, usually involves unloading the beam that cause great cost. The presented design idea to solve this problem is adding triangular shear panels to the corners of this system to make them dissipate energy and carry the resulted damage. Elimination of damage in link beam reduce the cost of reconstruction because these panels are easy to be replaced.The purpose this paper is to investigate the efficiency of corner plates in improving the behavior of Eccentrically Braced Frames. For this purpose, stiffness of the tension shear panels is calculated and the total system stiffness is obtained by adding stiffness of these panels to the stiffness of braces with rigid beam through calculating the tension field inclination angle and applying the PFI method. To verify the resulted relations, numerical analysis was used and all geometric and material nonlinearities were considered.The results show that the triangular shear panels slightly affect the shear capacity of the whole system. The inclination angle of the tension field is also less than the angle of the rectangular panel. Also, buckling of the compression brace is inevitable in this system

Keywords:

Analytical study , Eccentrically Braced Frame , Triangular Shear Panels