SEISMIC ANALYSIS OF STEEL FRAMED BUILDINGS WITH SELF-CENTERING FRICTION DAMPING BRACES

This paper deals with a novel type of passive energy dissipation device termed self-centering friction damping brace (SDB) and its application to seismic hazard mitigation of steel concentrically braced framed buildings. The SDB uses superelastic Nitinol wire strands to enable its self-centering mechanism and enhanced energy dissipation capacity is achieved by friction effect over the sliding surfaces of SDB. Unlike conventional passive damping devices, SDB has the potential to minimize the permanent drifts of concentrically braced frames after strong earthquakes and withstand several moderate earthquakes without the need for repair or replacement. Experimental results of SDBs presented here demonstrate its self-centering capability. Nonlinear time history analysis which involves a 3-story steel framed building subjected to two suites of twenty earthquake ground motions was conducted and the analysis results are presented in this paper. It is shown that SDB can effectively control the seismic response of framed building structures while minimizing their permanent drifts