Comparison of non-locking incompressible multi-field finite element models for dielectric actuators

Schlögl T, Leyendecker S (2016)


Publication Language: English

Publication Type: Conference contribution, Abstract of a poster

Publication year: 2016

Event location: Helsingoer DK

Abstract

Four Neo-Hookean material models are investigated, each model is tested with three numerical examples that are typical for dielectric actuator simulation. Model I is based on a classical displacement formulation, extended by electromechanical coupling terms. Model II is formulated in analogy to a nearly incompressible three-field formulation for pure mechanical problems. Model III extends model II by another field accounting for incompressibility. Finally, model IV is an attempt to decrease the amount of additional fields necessary to obtain incompressible behaviour. The first numerical example is a DEA cube where all sides except the top are fixed and an applied voltage exerts pressure to part of the top surface. The second example is a switch in form of a small stacked dielectric actuator that is connected to a rigid body with a revolute joint. The last example is a revolute joint controlled by two stacked actuators in agonist/antagonist configuration. The results show that material model I is not suited to approximate the incompressible material behaviour of dielectric elastomers. Large Poisson ratios inevitably lead to volume locking, even though the model is quite easy to implement and computationally very quick. Model II covers nearly incompressible behaviour very well in all applications, but the computational cost rises by a factor of about 2.6 compared to model I. Model III performs quite well, especially in combination with the structure preserving time integration scheme, allowing for exact incompressibility without any significant increase in computational cost. Model IV remarkably not decreases the computational cost compared to model III and hence does not offer any notable advantage.

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How to cite

APA:

Schlögl, T., & Leyendecker, S. (2016, June). Comparison of non-locking incompressible multi-field finite element models for dielectric actuators. Poster presentation at EuroEAP, Helsingoer, DK.

MLA:

Schlögl, Tristan, and Sigrid Leyendecker. "Comparison of non-locking incompressible multi-field finite element models for dielectric actuators." Presented at EuroEAP, Helsingoer 2016.

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