3. Test programme
A series of centrifuge tests was conducted at 50 g to capture the effects of various tuned and de-tuned mass damper configurations on the two-degrees-of-freedom sway frame structure interchangeably positioned on two soil profiles. Each centrifuge test consisted of multiple flights resembling a range of design earthquakes in which the structural response to unique configurations between the structure and damper was investigated, including configurations in which the damper was de-tuned away from the soil-structure system's fundamental frequency. This
was done in order to resemble practical scenarios whereby changes in soil-structure system properties may directly result from an earthquake. The SAM actuator was used to produce a wide range of earthquakes in the form of harmonic input motions of constant frequency as well as frequency sweep earthquakes which roll down from a high frequency to a low frequency and cover a wide frequency spectrum. The size and sequence of earthquakes was kept mostly the
same throughout all centrifuge flights in order to enable direct comparison between different tests.