Snap-through oscillations of tandem elastic sheets in uniform flow

Abstract

For smart system designs based on elastic structures, buckled elastic sheets where both edges are clamped have gained significant attention as they exhibit interesting dynamic behaviors, namely, snap-through motion. In this study, the critical conditions and post-equilibrium responses of tandem buckled sheets under unbounded uniform flow are investigated experimentally to understand the mutual interactions of the two sheets for potential applications as novel energy harvesting systems. The critical velocity at which they initiate snap-through oscillations from an equilibrium state is examined by varying the gap distance and initial buckled shape of the tandem sheets. The dynamic characteristics of the oscillation state, such as the amplitude, frequency, and phase difference, are examined with a particular focus on comparing the behaviors of the two sheets. Regardless of the gap distance, free-stream velocity, and initial buckled shape, the front and rear sheets exhibit similar deformation magnitudes and bending energies under repeated snap-throughs, which is notably different from flapping flag models with a free end. © 2021 Elsevier Ltd