Effect of Link Beam Length of the Eccentric Bracing System on Seismic Rehabilitation of Weak Reinforced Concrete Frames

In this study, A reinforced concrete (<i>RC</i>) reference specimen with compressive strength of <i>250 kg/cm</i><sup>2</sup> and the weak <i>RC</i> for seismic rehabilitation <i>150 kg/cm2</i> were examined in two types structures <i>6</i> <i>12</i>-stories. The link beam lengths <i>50</i>, <i>80</i>, <i>100 cm</i> have been used <i>12</i>-stories prototypes under effect <i>7</i> earthquake records. nonlinear dynamic analyses are performed. Then, behavior depends on its length. For short lengths, shear is serious, then medium shear-flexural important, finally, long will flexural beam. eccentrically braced frames, details fit other members must be done such a way as to ensure proper ductility. According obtained results, performance beams much better than beams, provide more energy dissipation and, at same time, Therefore, design beam, mainly considered ductile component. axial force which due application lateral load structure, reduces both bending capacity inelastic deformation so it can explained that steel eccentric braces, symmetrical between main components brace affect structure against loads.