Evaluating reduced order models of curved beams for random response prediction using static equilibrium paths

Publication date: Available online 17 October 2019Source: Journal of Sound and VibrationAuthor(s): C.I. Van Damme, M.S. Allen, J.J. HollkampAbstractThin curved structural components are susceptible to dynamic snap-through when subjected to the high amplitude aerodynamic loading that is present in extreme environments. In order to estimate the life of the structures, time simulations must extend over many seconds so that the statistical response due to the random loading environment can be adequately characterized. In order to compute the geometrically nonlinear response of these structures in a reasonable time, Reduced Order Models (ROMs) have been developed that reduce the computational burden dramatically. However, the accuracy of a ROM can vary drastically depending on how it is created, specifically depending on which modes are included within the basis set and the magnitude of the static loads used to estimate the nonlinear stiffness coefficients in the ROM. This work presents a procedure to check that a ROM is accurate in dynamic snap through prior to computing the dynamic response. The Riks method is used to compute the static equilibrium path, or force-displacement behavior, for both the FE model and the ROM, and by comparing these one gains insight into the character of the ROM. Two curved beams are studied to validate the procedure and we identify load levels and mode sets that produce accurate ROMs for these structures. The ROMs are further validated by computing t...
Source: Journal of Sound and Vibration - Category: Physics Source Type: research