Seismic assessment of concentric X-braced steel frames

Aim of the present paper is to propose a simplified approach for the assessment of steel braced frames with X configuration (X-CBFs) according to a procedure developed in the light of the Direct Displacement Based Design method (DDBD). The whole procedure aims at to derive the nonlinear response of X-CBFs by examining the role of specific assessment parameters in terms of ductility and energy dissipation. Numerical applications are presented in the paper by applying the developed procedure. The comparison between the obtained results and the corresponding ones deduced from nonlinear static and dynamic time history F.E. analyses are carried out in order to check the reliability of the proposed approach.