Theory of plastic mechanism control for the seismic design of braced frames equipped with friction dampers

•Innovative approach for the design of a dual system with system equipped with friction dampers.•Activation of all the friction dampers requires an advanced design procedure.•The theory of plastic mechanism control is applied.

An innovative approach for the design of a seismic resistant system composed by the combination of a MR-Frame and a bracing system equipped with friction dampers is presented. From a multi-scale point of view, at local scale, supplementary energy dissipation is provided by means of friction dampers, while, at global scale, the development of a global type mechanism is assured involving all the friction dampers equipping the structure. The activation of all the friction dampers requires an advanced design procedure. Toward this end, the theory of plastic mechanism control, which is based on the application of the kinematic theorem of plastic collapse is extended to the concept of mechanism equilibrium curve, is applied. The fulfillment of the design goal has been pointed out by means of both pushover and dynamic non linear analyses whose results are herein presented and discussed.