Building Subjected to Nonstationary Ground Excitation

The structure is subjected to base acceleration given by stationary white noise with spectral intensity Sgo = 0.25 m s modulated by  

Bayesian Methods for Structural Dynamics and Civil Engineering 

As observed previously in the examples for the Bayesian spectral density approach, the coefficients of variation for the frequencies in all cases are much smaller than those of the damping ratios, indicating that frequencies are identified much better than damping ratios. An additional result observed, but not tabulated here, is that the modal damping ratios exhibit significant correlation with the corresponding modal forcing spectral intensifies. 

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