Abstract:
The use of adjustable Amplitude Frequency Characteristics (AFC) approach is a new concept in
vibration mitigation, which is developed from frequency detuning technique used in vibration
protection against resonance. This non-constant APC can be generated by Magnetorheological (MR)
fluid-based pins, so called 'smart pins', which are mounted at beam-column connections.
The paper presents a preliminary investigation of a 'smart' -pin-frame system, a single-storey, one bay,
steel plane frame with a traditional pin and a 'smart' pin mounted at each beam-column end, whose
frequencies can be adjusted by partially 'locking' or 'releasing' the smart pin. To do so, a maximum
or zero DC current level is supplied to the smart pin, which respectively transforms the system into
either pin-rigid (P-R) or pin-pin (P-P) beam in a frame structure.
Experiments, conducted in the Structure Laboratory of the University of Technology, Sydney (UTS)
using both a sudden release technique and a shake table, were used to investigate the non-linear
dynamic properties and the system AFC prior to their 'proof-of-concept' testings. Preliminary AFC
results showed the potential use of the system subjected to harmonic forced vibrations.
