Modeling and Simulation of Viscous Electro-Active Polymers

Area of Science:

• Materials Science
• Mechanical Engineering
• Polymer Science

Background:

• Electro-active polymers (EAPs) deform under electric fields, with electronic EAPs utilizing Coulomb forces or polar group reorientation.
• Many electronic EAPs exhibit significant viscoelastic properties, complicating their mechanical response.
• Understanding and modeling these viscoelastic behaviors under electric fields is crucial for EAP applications.

Purpose of the Study:

• To develop and implement a constitutive model for electronic EAPs.
• To capture the influence of electric fields on the viscoelastic response within a nonlinear finite element framework.
• To investigate the impact of electro-viscous coupling on material behavior.

Main Methods:

• Developed a constitutive model incorporating electric field effects into both equilibrium and viscous strain energy components.
• Formulated governing equations in logarithmic strain space, additively decomposing strain into elastic and viscous parts.
• Implemented the model within a geometrically nonlinear finite element framework and performed parametric studies.

Main Results:

• The model demonstrates that electric fields significantly alter the relaxation and hysteresis behavior of EAPs.
• Parametric studies show the model's sensitivity to electro-viscous coupling parameters.
• Simulations of actuator structures validate the model's performance in relaxation and creep scenarios.

Conclusions:

• The developed constitutive model effectively captures the electro-viscoelasticity of electronic EAPs.
• The model provides a valuable design tool for micro-electro-mechanical systems, microfluidic devices, and artificial muscle applications.
• Accurate modeling of electro-viscous coupling is essential for predicting EAP performance.