The Transamerica Pyramind has a Fundamental Frequency of 0.3 Hz * * * Here are some papers which give natural frequencies and damping values for sample tall buildings: Damping in Tall Buildings and Towers: tall_building_damping.pdf The Damping Characteristics of Bolted and Welded Joints: bolted_joint_damping.pdf Transamerica… Read more
Here is a project that my NASA colleagues have been working on: FSC_damper.pdf The original goal of the project was to use the Ares I second stage as a LOX damper to mitigate the first stage thrust oscillation. See also: http://blogs.nasa.gov/cm/blog/Constellation.blog/posts/post_1239311627391.html – Tom Irvine
Please see the following update: MDOF Frequency Response Function Natural Frequency & Damping Extraction including Modal Overlap. Post Link The half-power bandwidth method can be used to estimate the damping ratio and corresponding Q value from the frequency response function of a structure which has… Read more
Here is a Matlab GUI script which converts between various damping metrics: damping.zip The supported metric include: quality factor Q fraction of critical damping [zeta] loss factor [eta] 3 dB Bandwidth [delta omega] 3 dB Bandwidth [delta f] damping frequency [fd] decay constant [sigma] time… Read more
Piezoelectric shunt damping systems reduce structural vibration by shunting an attached piezoelectric transducer with an electrical impedance. Current impedance designs result in a coupled electrical resonance at the target modal frequencies. Piezoelectric transducers (PZTs), in conjunction with appropriate circuitry, can be used as a mechanical… Read more