Seismic design spectra for friction-damped structures

A simplified seismic design procedure is proposed for structures equipped with an innovative friction-damping system. The system has been shown experimentally to perform very well and could represent a major new development in earthquake-resistant design. This paper first presents an efficient modeling approach for the seismic analysis and design of friction-damped 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 slip-load distribution for the friction dampers. The results of the study lead to the construction of a design slip-load spectrum for the rapid evaluation of the optimum slip-load 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 slip-load spectrum should lead to a greater acceptance by the engineering profession of this innovative design concept.