Comparative Review of the Performance Based Design of Building Structures Using Static Non-Linear Analysis, Part A: Steel Braced Frames

The objective of this review to be submitted in two independent parts, for steel frames and for RC frames, is to compare their structural performance with respect to the proposed N2-method, and so also of the consequent convenience of using pushover methodology for the seismic analysis of these structures. A preliminary investigation is presented on a pushover analysis used for the seismic performance of metallic braced frames equipped with diagonal X-bracing and K-bracing systems. Three steel frames are analysed corresponding to 3, 6 and 10 floor regular buildings that were modelled in the MIDAS/Civil finite element software. To obtain the pushover curve a non-linear static methodology is used. For the RC frames three commercial programs (SAP 2000, SeismoStruck and MIDAS/Civil) are used in order to perform a parametric study based on pushover analyses. The equivalent strut method is applied to simulate the influence of the masonry infill panels; to evaluate the influence of these on the capacity curves, several strut width values are considered. The parametric study also addresses the influence of other parameters on the structural behaviour and non-linear capacity curves of the RC frame, namely: length and position of the plastic hinges and different loading patterns (uniform, modal and triangular distributions).