A numerical study of instability transition of a beam-like plate with imperfections loaded by a steady axial airflow

The actual plate structures are not as ideal as the general theoretical analysis. They are potentially subjected to imperfections, significantly influencing their instability behaviors when they vibrate in fluids. On the one hand, the possible imperfections come from the structure itself, and on the other hand, they come from the mismatch between theoretical and experimental modelings. The lack of influence analysis of imperfections will lead to many deviations in our understanding of the structure's mechanical properties and the experimental results. This brief note presents a numerical study on the instability of a plate with two types of imperfections: the crack defect and imperfect edge-support, and reveals the influence of these imperfections on the plate instability behaviors when the plate is subjected to a steady axial airflow. The crack defect is modeled as an all-over part-through crack in the plate and the imperfect edge-support as elastic end support with transversal and rotational springs. For the uncracked plate, the elastic end support allows the coexistence of the flutter and divergence instability. The rotational spring plays a vital role in the distributions of instability regions and the transition of two instability types. The plate exhibits more complicated instability behaviors with the effect of both crack and elastic end support. There will be transitions between instability regions, and the instability transition processes between different instability types are more diversified.