Ambient vibration survey

Another important practical category is the ambient vibration survey (AVS). It has attracted much interest because it offers a means of obtaining dynamic data in an economical and efficient manner, without requiring the setup of special dynamic experiments (e.g., actuators) which are usually costly, time consuming, and often obtrusive. In AVS, the naturally occurring vibration... 

Chapter 3 presented the Bayesian spectral density approach for the parametric identification of the multi-degree-of-freedom dynamical model using the measured response time history. The methodology is applicable for linear models and can also be utilized for weakly nonlinear models by obtaining the mean spectrum with equivalent linearization or strongly nonlinear models by obtaining the mean spectrum with simulations. The stationarity assumption in modal/model identification for an ambient vibration survey is common but there are many cases where the response measurements are better modeled as nonstationary, e.g., the structural response due to a series of wind gusts or seismic responses. In the literature, there are very few approaches which consider explicitly nonstationary response data, for example, [226,229]. Meanwhile, extension of the Bayesian spectral density approach for nonstationary response measurement is difficult since construction of the likelihood function is nontrivial in the frequency domain. Estimation of the time-dependent spectrum requires a number of data sets, which are associated with the same statistical time-frequency properties but this is impossible to achieve in practice. 

Beck, J. L., Vanik, M. W., Polidori, D. C. and May, B. S. Ambient vibration surveys of a steel frame building in a healthy and damaged state. Technical Report EERL 97-03, California Institute of Technology, Earthquake Engineering Research Laboratory, Pasadena, CA, 1997. 

Brownjohn, J.M., Dumanoglu, A.A., Severn, S.T., Taylor, C.A.(1988) Ambient Vibration Survey of Humber Suspension Bridge. Research Report, University of Bristol. 

Ambient Vibration Survey of the Bosporus Suspension Bridge. Research Report, University of Bristol. 

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