Self-Oscillation in Active Wires with Asymmetric Willis-Type Viscosity

Area of Science:

• Materials Science
• Mechanical Engineering
• Physics

Background:

• Wires are crucial for large-span, lightweight structures.
• Self-oscillation in structures can enhance autonomous dynamic functions.
• Existing self-oscillation methods are complex, limiting wire applications.

Purpose of the Study:

• To propose a simple strategy for self-oscillating wires.
• To design active wires with electro-magneto-mechanically coupled feedforward loops.
• To realize irreversible coupling between strain rate and body force.

Main Methods:

• Extending Willis elasticity to Willis-type viscosity.
• Designing active wires with coupled feedforward loops.
• Conducting numerical experiments and using continuum models.

Main Results:

• Achieved biased limit-cycle self-oscillation in active wires.
• Demonstrated linear amplification of oscillation amplitudes in one direction.
• Interpreted linear amplification via asymmetric Willis viscosity.
• Showcased independent tailoring of oscillation mode shape and frequency.
• Observed standing-propagating mode transition in active wires.

Conclusions:

• The proposed design enables autonomous dynamic functions in wires.
• Asymmetric Willis viscosity is key to linear amplification.
• The approach offers control over oscillation modes and frequencies.
• This work advances autonomous materials for large-span structures.