Seismic design methodology for friction damped braced frames

This paper is concerned with the design of steel frames using friction damped slotted bolted connections (SBCs) in the diagonal braces. A dynamic model is developed to describe the behaviour of a single-degree-of freedom (SDOF) steel frame that uses bilinear hysteretic behaviour for the damper. This model is generalized to MDOF systems. A novel algorithm for displacement reversal in the transition from slip to stick is presented. It uses numerical noise for its success. A design procedure that attains the stiffness of the individual braces and their elongation at the threshold of activation is then applied to a 10-storey steel frame. This design process is a two-phase iterative procedure that converges quite fast. Copyright (C) 2000 John Wiley & Sons, Ltd.