Numerical evaluation rigid connection with Replaceability corners in flexible tree frames

One of the systems resistant from to lateral load is the flexible from. The joints of the flexible frame are designed as rigids in these flexible frames, the purpose of the design is so that the plastic joint is removed from the connection point and placed on the beam. For this purpose and create a plastic joint in the beam, systems such as Reduce section are used.by weakening the beam in the critical area, causes the plastic joint to come out of the connection point on the beam. In this article, a replaceable connection has been achieved by using the Reduced section method and the patch system with up and underskirt sheets. That many problems in the reduced section have been solved and the behavior of the system has been improved. By using replaceable system, the structure has been repaired at a high speed after the earthquake and also its cost is very low. In this article, eight models have been evaluated numerically with Abaqus finite element software. Good results have been achieved by examining the cyclical and functional diagrams obtained from the models. In addition to the fact that the plastic joint has been removed from the connection point and placed on the beam, the possibility of being replaceable has also been added to the designed model, which has improved the problems to some extent