Parametric Instabilities in Elastic Structures under Stochastic Loading

Abstract
The dynamic stability of nongyroscopic, elastic structures under parametric random loading of small intensity is investigated. Conditions for stability in the second norm of the dynamic response are obtained and shown to depend only on those values of the excitation spectral density near twice the natural frequencies and the combination frequencies of the structure. As an application, the flexural-torsional stability of a simply supported thin elastic beam subjected to stochastically fluctuating end couples is studied.