Chevron concentrically braced frames: proposal of seismic design criteria for the next generation of Eurocodes

Nowadays, in Europe there is a growing research effort in the field of the codification review and development, in which both academic institutions, and technical committees and organizations of designers and practice engineers are strongly involved. Within this framework, the research activity summarized in this thesis is focused on seismic design of steel structural buildings equipped with concentric bracings in chevron configuration (CCBs). The main objective of the thesis is to develop new design criteria to improve ductility and seismic performance against seismic action of chevron bracings. With this regard, a critical review of existing design criteria provided by both European and North-American seismic codes is provided, in order to identify all issues in the current version of EN 1998-1 needing clarification and/or development, aiming at contributing to a new generation of European codes. The main structural parameters affecting the seismic performance of CCBs are identified and the effectiveness of existing codified design rules is assessed by means of a comprehensive parametric study on a set of structural steel buildings. In the light of these numerical results, new design criteria for ductile and dissipative CCBs are proposed and validated by means of a comprehensive set of numerical analyses.