Flow-Induced Buckling of a Bistable Structure in Uniform Flow

Recent developments in soft materials have enabled the design of bistable, flexible structures. We explore the snap-through buckling process of these bistable structures driven by fluid flows, modeling the fluid-structure interaction coupling via the Arbitrary Lagrangian-Eulerian method. In the first scenario, three flexible plates with varying geometries and no initial stress are subjected to fluid-driven motion at different flow speeds. We analyze the structural deformation patterns, hydrodynamic force distributions, and fluid dynamics patterns during the snap-through buckling process. We identify the Cauchy number as a key dimensionless parameter governing bistable structures' snap-through buckling and structural strain energy storage. Predictive models for the structural dynamics' dimensionless strain energy and rise time were developed. Additionally, we examine how vortex shedding, associated with the hydrodynamic lift force, affects the structural strain energy. We also find that bistable structures exhibit larger steady-state deformation than mono-stable structures in the same flow conditions, suggesting that structural bistability significantly influences fluid-structure interaction.