Harmonically Induced Shape Morphing of Bistable Buckled Beam with Static Bias

Area of Science:

• * Solid Mechanics
• * Nonlinear Dynamics
• * Metamaterials Engineering

Background:

• * Bistable beams exhibit two stable equilibrium positions, making them suitable for adaptive structures.
• * Dynamic excitation can induce shape morphing in these beams, but control remains a challenge.
• * Understanding the influence of static bias forces is crucial for precise control of bistable systems.

Purpose of the Study:

• * To investigate the impact of a constant static bias force on the dynamic shape morphing of pre-buckled bistable beams.
• * To explore the different types of oscillatory motions (switching, reverting, vacillating, intra-well) induced by harmonic excitation.
• * To determine the conditions for achieving state transitions with minimal excitation amplitude.

Main Methods:

• * Analysis of a pre-buckled bistable beam model subjected to harmonic excitation and a static bias force.
• * Exploration of the parameter space to categorize different oscillatory motion regimes.
• * Numerical investigation of the beam's dynamic response and state-switching behavior.

Main Results:

• * The static bias force significantly influences the dynamic morphing and oscillatory behavior of the bistable beam.
• * Synergistic effects between dynamic excitation and static bias force were observed, broadening the non-fractal region for switching.
• * Four distinct categories of oscillatory motion were identified: switching, reverting, vacillating, and intra-well.

Conclusions:

• * Static bias forces offer a means to control and enhance the dynamic shape morphing of bistable beams.
• * The findings advance the understanding of multi-stable mechanical metamaterials, crucial for adaptive applications.
• * This research provides insights for designing novel adaptive structures with improved control over stable state transitions.