Truncation of high frequency modes Structures are continuous systems so that they always have an infinite number of poles. Frequency DMF 32, no. It is thus both natural and efficient to analyze spectra dominated by structural resonances on a logarithmic frequency scale with a constant percentage bandwidth somewhat narrower than the … The results of this investigation are of paramount importance, as they suggest that soil–structure interaction primarily controls the overall damping ratio of buildings … ... etc. 4. Exam D225 – Dynamics of Mechanical Systems, C105 Mechanical and Structural Engineering and the Edexcel HNC/D module Mechanical Science. The damping ratio, ζ, can be determined by computing Q, defined as the resonant frequency divided by the half power bandwidth around the peak at f n. Q factor is computed as: where f n is the resonant frequency at the peak in Hz; f 1 and f 2 are the half power points measured -3 dB down from the peak as shown in Figure 11. ... Afy /th half-power frequency, Aq =