Theory of Plastic Mechanism Control for Linked Column Frames

The main purpose of this work is to define a design procedure for dissipative replaceable link frames (LCFs). These structural schemes are characterized by the columns connected with link elements representing the plastic zones of the structure and, consequently, they assure the maximum dissipation of seismic energy in input. The design rules, proposed in this paper, are based on the Theory of Plastic Mechanism Control (TPMC). This procedure is based on the extension of the kinematic theorem of limit analysis to the concept of the equilibrium curves of the failure mechanisms and it guarantees the achievement of the global collapse mechanism under severe seismic actions. In order to evaluate the accuracy of this procedure, a case study is presented. In particular, a LCF with four storeys and three bays is designed by means of the proposed design rules. Finally, the same steel frame is implemented in SAP2000 program, and a pushover analysis is performed to evaluate the ultimate behaviour of the modelled structure.