evaluation of pushover analysis with an energy based approach in regularity concrete structures

 the nonlinear static analysis methods have been made to estimate strength and deformation capacities of a structure and compare these capacities with demands of performance levels. selecting roof displacement as a displacement control point in higher modes is one of difficulties and limitations available in nonlinear static analysis methods, so in some structures, during constructing capacity spectrum curve for mode 3, because roof displacement isn’t proportional to displacement of other stories, and with increasing base shear, roof displacement decreases. one of the proposed methods for removing available ambiguities in selecting roof displacement as a displacement control point in nonlinear static analysis methods is the use of energy-based capacity spectrum method which is not only a magnitude roof displacement, but also effects magnitude and the direction of roof displacement in determining an equivalent of one degree of freedom building model displacement are also considered. in this investigation, the results of nonlinear static analysis methods obtained based on energy-based capacity spectrum are compared with the results obtained from nonlinear dynamic analysis in reinforcement concrete frame by the use of perform-3d software. this research shows that the results of nonlinear static analysis methods achieved by using an energy-based capacity spectrum have acceptable efficiency.