Seismic Design Spectra for FrictionDamped Structures

A simplified seismic design procedure is proposed for structures equipped with an innovative frictiondamping system. The system has been shown experimentally to perform very well and could represent a major new development in earthquakeresistant design. This paper first presents an efficient modeling approach for the seismic analysis and design of frictiondamped structures. The hysteretic properties of the friction dampers are derived theoretically and are included in a Friction Damped Braced Frame Analysis Program FDBFAP, which is adaptable to a microcomputer environment. FDBFAP is then used to perform a parametric study of the optimum slipload distribution for the friction dampers. The results of the study lead to the construction of a design slipload spectrum for the rapid evaluation of the optimum slipload distribution. The spectrum takes into account the properties of the structure and of the ground motion anticipated at the construction site. The availability of this design slipload spectrum should lead to a greater acceptance by the engineering profession of this innovative design concept.