چكيده انگليسي :
In the present research, the optimal functional design of special reinforced concrete moment frame structures has been designed under DBE and MCE earthquake hazard levels. In recent years, many studies have focused on the optimal functional design of structures. But often, the purpose of designing those studies was to limit the relative story drift of structures, in this study, however, the rotation of the plastic hinge was limited to the allowable limits. For this purpose, first, special reinforced concrete moment frames of 4, 8, and 12 stories were designed in three dimensions by ETABS software according to the criteria of ACI318-19. Structural modeling in OpenSEES object-oriented finite element software has been nonlinear, with the concentrated plastic hinge method. The analyzes were in the form of nonlinear time history, under 11 pairs of accelerograms compatible with type D soil ASCE7-16 loading regulation was designed at two levels of DBE and MCE earthquake. It should be noted that the reason for using the above nonlinear modeling method was to investigate the effect of cyclic deterioration, under the criterion of rotation of plastic hinge of beams and columns. The optimization process has been such that has been used the algorithm of uniformity of deformations (Rotation of the plastic hinge). Thus, in each repetition, the results of nonlinear responses of rotation of the plastic hinge of beams and columns are extracted from the software, and after averaging the responses of 11 acceleration pairs, the mean responses of the members' plastic hinge were controlled by the above optimization algorithm in MATLAB software, with the allowable values of ASCE41-17 improvement regulation. Simultaneously, the damage index of each member of the structural members is calculated and based on the values of the damage index, the values of the new optimal reinforcement consumption density of beam and column sections, also, the new optimal cross-sectional area of the beams and columns were determined based on the above criteria.
It should be noted that in each optimization process, were controlled all the criteria of design and improvement regulations, including the criteria of strength, the relative drift of structure’s stories, control of geometric dimensions of beams and columns, controls related to the flexural frame criteria for reinforced concrete are included weak beams-strong columns and control of the allowable amount of density of longitudinal reinforcement at the location of the panel zones, as well as the amount of rotation of the plastic hinge of the members. The results of the final diagrams showed that are optimized the costs of 4, 8, and 12 story structures under the DBE earthquake were 43.42%, 46.55%, and 45.58% respectively, and also under the MCE earthquake of 20.83, 30.36% and 30.23%, respectively which is a significant amount. reinforcement consumption density of 4, 8, and 12 story structures under the DBE earthquake were 58.41%, 60.57%, and 61.04% respectively, and also under the MCE earthquake of 37.43, 40.91% and 42.76%. concrete consumption volume of 4, 8, and 12 story structures under the DBE earthquake were 44.53%, 44.29%, and 42.33% respectively, and also under the MCE earthquake of 10.74, 28.33% and 24.76% . the time required to reach the optimal state in the case of parallel operations with 8 cores, for 4, 8 and 12-story structures under DBE earthquake 17, 44, 64 hours, respectively, and also under the MCE earthquake were 10, 30 and 35 hours, respectively. This shows the efficiency of the optimization method used. The diagrams also showed that the optimization under the DBE earthquake was performed to a greater extent than the MCE earthquake. The results of the diagrams and Appendix 1 show that is improved the damage and deformation index of the members is uniformly distributed and the performance of the structure under earthquake.
