Saeid choopani - Master student, Civil Engineering, Structural Orientation, Sajjad University of Mashhad, Mashhad, Iran.

In this research, the behavior coefficient of 4, 2 and 8 layer reinforced concrete frames with medium and special ductility based on the proposed accurate nonlinear analysis has been. First, for validation, the nonlinear analytical model proposed in this research is compared with existing laboratory models. Results Validation shows that the proposed model has a very high accuracy. To obtain the coefficient of behavior of reinforced concrete frames 4, 2 and 8 classes of variable axial force effects, shear failure of members as well as buckling of longitudinal rebars are considered in nonlinear analysis. Direction calculating the coefficient of behavior, two criteria are considered to calculate the final deformation of the frames. The first criterion is based on the displacement of the corresponding frames. The final period and the second criterion are considered critical members based on the displacement corresponding to 0.97 of the final period. The results show that the coefficient of behavior Calculated reinforced concrete flexural frames with medium and special ductility with displacement corresponding to 0.97 of the final period of the critical member, to the coefficient of behavior. The presentation is closer to the 2800 standard. Also in reinforced concrete frames with medium ductility, the amount of ductility increases with height. The frames are reduced, which is not the case for reinforced concrete frames with special ductility.

Behavior coefficient, Reinforced concrete flexural frame, nonlinear analysis, Variable axial force, Shear failure, Ductility.