A New Modal Identification Method Under the Non-Stationary Gaussian Ambient Excitation

DU Xiu-li; WANG Feng-quan

doi:10.3879/j.issn.1000-0887.2009.10.009

Volume 30 Issue 10

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DU Xiu-li, WANG Feng-quan. A New Modal Identification Method Under the Non-Stationary Gaussian Ambient Excitation[J]. Applied Mathematics and Mechanics, 2009, 30(10): 1213-1222. doi: 10.3879/j.issn.1000-0887.2009.10.009

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A New Modal Identification Method Under the Non-Stationary Gaussian Ambient Excitation

doi: 10.3879/j.issn.1000-0887.2009.10.009

DU Xiu-li¹,
WANG Feng-quan²

1.
College of Mathematical Sciences, Nanjing Normal University, Nanjing 210046, P. R. China;

Received Date: 2009-01-06
Rev Recd Date: 2009-07-10
Publish Date: 2009-10-15

Abstract

Abstract

Based on the multivariate continuous tmie autoregressive model, a new time-domain modal identification method of LTI system driven by the uniformly modulated Gaussian random excitation was presented. The method canidentify the physical parameters of the system from the response data. First, the structural dynamic equation is transformed into the continuous tmie autoregressive model of order 3. Second, based on the assumption that the uniformly modulated function is approx miately equal to a constant matrix in a very short time period and the property of the strong solution of the stochastic differential equation, the uniformly modulated function is identified piecewise, an d two special situations are discussed too. Finally, by virtue of the Girsanov theorem, a likelihood function was in troduced, which is just a conditional density function. Maxmiizing the likelihood function gives the exact maximum likelihood estmiators of model parameters. Numerical results show that the method has high precision and computing efficiency.
- modal identification,
- uniformly modulated function,
- continuous time autoregres-sive model,
- Brownian motion,
- exactmaximum likelihood estmiator

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References(15)

References

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