A Numerical Capacity Spectrum Method for nonlinear analysis of RC frame structures

A new capacity spectrum method, named Numerical Capacity Spectrum Method, is presented to make the capacity spectrum method simply. Some disadvantages of the current capacity spectrum method are researched. One is that the earthquake-induced deformation of an inelastic single degree freedom system is estimated by an iterative method, which is very inconvenient; another is that the method is a diagram method, which is not accurate because it depends on the level of researchers. The problems are solved by the Numerical Capacity Spectrum Method gotten from solving the functions of inelastic demand spectra and capacity spectra. The improved method is used to estimate the requisite displacement at Performance Point of four RC frame structures, 7-story, 9-story, 11-story and 13-story respectively, the results indicate that the presented method is not only accurate but also simple.