Flow-Induced Snap Through of Bistable Arches With Generalized Boundary Conditions

Abstract Fluid–structure interactions (FSIs) can be successfully leveraged to develop passive fluid control systems and active structures that respond to targeted flow conditions. When bistable structures interact with flowing fluids, interesting dynamics, such as large reconfigurations due to snap-through instability, can arise. Here, we demonstrate how to control the flowrate of a viscous fluid in a channel by tuning the boundary conditions of a bistable arch (i.e., postbuckled beam) incorporated along the channel sidewall. We introduce a torsionally supported postbuckled beam immersed in fluid flow to investigate flow–deformation relationships, surface pressure distributions, and critical flowrates. Varying torsional spring stiffness allows to span from clamped-clamped to hinged-hinged, and all intermediate stiffness rotational boundary conditions. We develop an analytical model and numerical continuation methods to determine the critical flowrate required to snap the bistable arch and the effects of the support’s torsional stiffness. Thanks to this approach, we demonstrate a wide range of attainable critical flowrates that can be tuned by varying the boundary conditions of the bistable arch.