عنوان مقاله [English]
The purpose of this study is to evaluate the direct displacement based seismic design (DDBD) method in the design of reinforced concrete shear walls.Direct Displacement- Based Design has been developed by Priestley et al with the aim of mitigating the deficiencies in current force-based design. In this method displacement leads to strength which inverts the process of traditional force-based design where strength leads to an estimate of
displacement.For this purpose, four reinforced concrete shear walls with different heights (4, 8, 12 and 16 floors) are considered and designed based on the displacement based seismic design method for a specified drift at roof
level.Nonlinear time history analyses method with incremental acceleration (IDA) is used in order to analyze the shear walls. By comparing the results of analyses with the design assumptions it can be seen that the displacements predicted by direct displacement based design method conservatively has a considerable difference with the results of time history analyses.Therefore, it is expected that in order to reach a certain displacement, the base shear of shear walls be less than the base shear resulted from DDBD method. With studies done, the reasons of this difference were investigated. For this purpose, some of the assumptions of DDBD method such as Yield curvature, Yield displacement and Base shear and the basis of substitute structure assumption
are considered and corrective recommendations are presented. By performing proposed modifications in Direct Displacement Based Design, the designs of shear walls are repeated. In this case in which the design method is based on the modified method, the conformity of analyze results from time history analyses and the design assumption is quite obvious. In this study the nonlinear beam-column element is used to model reinforced concrete shear walls and confirmed using WCOMD finite element software. Numerical modelling and analyses of shear walls are performed using OpenSees .