Tuned dynamic absorbers (TDA) find use, in particular, for attenuating tonal vibration export produced by the moving
components of cryogenic cooler. For the best performance, the resonant frequency of TDA needs to be essentially equal
the driving frequency; accurate frequency match is favorably achieved by minimizing the cooler induced vibration by
adjusting the driving frequency. For the best performance, the design of TDA needs to ensure minimum damping ratio;
this is achievable by using planar flexural bearings having zero friction anchoring features.
Accurate evaluation of effective mass, damping ratio and frequency is needed for TDA characterization during
development and manufacturing. This data may be also important for the dynamic modelling. The authors are exploring
the express method requiring no physical access to the proof mass of TDA. In this approach, the TDA is mounted upon
the low frequency vibration mounted rod, the dynamic properties of TDA are then evaluated using the frequency
response function – local accelerance – captured on the above rod using accelerometer, instrumented modal hammer and
dual-channel signal analyzer. The authors are presenting the TDA design, outcomes of full-scale experimentation on
dynamic properties evaluation and attained performance.