Vibration Mitigation Effect of a Friction Damper with Variable Resistances on the Steel Frame Structure

Analytical study was conducted to investigate effect of friction dampers on vibration control of steel frame structures. The friction dampers installed in a ten-storey sample frame structure have two levels of fictional resistances. Unlike the conventional friction damper which has one frictional resistance, the friction dampers with variable resistances (VRFD) can apply two levels of frictional resistances, the lower resistance of which is attended to absorb the seismic energy by a moderate earthquake or a strong wind, and the higher one of which is expected to dissipate the seismic energy induced by a severe earthquake. The time-historey analytical results of the sample frame have indicated that the VRFD could not only mitigate the seismic response of the frame structure under a moderate earthquake more effectively than the conventional frictional damper, but also provide the same level of damping effect to the structure under severe earthquake as the conventional one.