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AN OPTIMAL CONTROL APPROACH TO EXTREME LOCAL MAXIMA FOR STOCHASTIC DUFFING-TYPE OSCILLATORS

✍ Scribed by J.F. Dunne


Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
701 KB
Volume
193
Category
Article
ISSN
0022-460X

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✦ Synopsis


A new way is presented to calculate extreme exceedance probabilities associated with the height of local maxima on stationary sample paths of a non-linear oscillator driven by narrow-band Gaussian excitation. Deterministic ''least effort'' optimal control functions are used to construct a linear filter which is applied to the excitation process. By defining a suitable form of conditioning on the filter output local maxima, the most difficult problem can be switched around, so that use can be made of the conventional theory for a normal process. With subsequent simplifications, the required probabilities can be expressed just in terms of an unknown conditional mean and variance. An efficient numerical scheme is developed to estimate these two moments via non-linear regression using a small set of simulated oscillator sample paths. In testing the method on a Duffing-type oscillator with strongly non-linear stiffness and damping, comparison with conventional Monte Carlo simulation is concentrated in a probability range 10 -2 -10 -5 but using only about 1% of the local maxima normally required. The method offers a practical tool for use in the analysis of extreme non-linear random vibration.