Doubly spectral stochastic finite element method (DSSFEM) for random field problems

Sondipon, Adhikari and Roy, Mahapatra D (2009) Doubly spectral stochastic finite element method (DSSFEM) for random field problems. In: IISc Centenary International Conference and Exhibition on Aerospace Engineering ICEAE , 18-22 May, 2009, Bangalore, India.

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Abstract

Uncertainties in complex dynamic systems play an important role in the prediction of a dynamic response in the mid- and high-frequency ranges. For distributed parameter systems, parametric uncertainties can be represented by random fields leading to stochastic partial differential equations. Over the past two decades, the spectral stochastic finite-element method has been developed to discretize the random fields and solve such problems. On the other hand, for deterministic distributed parameter linear dynamic systems, the spectral finite-element method has been developed to efficiently solve the problem in the frequency domain. In spite of the fact that both approaches use spectral decomposition (one for the random fields and the other for the dynamic displacement fields), very little overlap between them has been reported in literature. In this paper, these two spectral techniques are unified with the aim that the unified approach would outperform any of the spectral methods considered on their own. An exponential autocorrelation function for the random fields, a frequency-dependent stochastic element stiffness, and mass matrices are derived for the axial and bending vibration of rods. Closed-form exact expressions are derived by using the Karhunen-Loève expansion. Numerical examples are given to illustrate the unified spectral approach.

Item Type:	Conference Paper
Publisher:	American Society of Civil Engineers
Additional Information:	Copyright of this article belongs to American Society of Civil Engineers.
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering)
Date Deposited:	19 Dec 2011 09:23
Last Modified:	19 Dec 2011 09:23
URI:	http://eprints.iisc.ac.in/id/eprint/40638

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