Analysis of the Novel Strain Responsive Actuators of Silicone Dielectric Elastomer

2008 ◽  
Vol 47-50 ◽  
pp. 298-301 ◽  
Author(s):  
Li Wu Liu ◽  
Jiu Ming Fan ◽  
Zhen Zhang ◽  
Liang Shi ◽  
Yan Ju Liu ◽  
...  
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
Large Deformation ◽  
Deformation Theory ◽  
High Efficiency ◽  
High Energy ◽  
Dielectric Elastomer ◽  
Dielectric Elastomers ◽  
Large Strains ◽  
The Novel

The acrylic acid and silicone are common dielectric elastomer materials. These actuators have shown excellent activate properties including large strains up to 380% and high energy densities up to 3.4 J/g, high efficiency, high responsive speed , good reliability and durability, etc. When a voltage is applied on the compliant electrodes of the dielectric elastomers, the polymer shrinks along with the electric field and expands in the plain area which erects the orientation of the line. In this paper, we synthesize a novel silicone dielectric elastomer with high dielectric constant, large strain and high force output. Pre-strain and certain driving electric field are applied on the novel silicone film, respectively. The strain responsing to the Maxwell stress is measured. Using the large deformation theory of finite element method to simulate the deformable behavior of materials, the simulation results agree with the experiment. The coupling effect of the mechanics and electric fields applied on the electrode of the dielectric elastomers is inverstigated. The finite element simulation of large deformation theory can be used to describe the dielectric elastomers materials large deformation that induced by the static electric field.

Electromechanical Stability of Dielectric Elastomer Using Electric Energy Density Function With Variable Dielectric Constant

2010 ◽  
Author(s):  
Liwu Liu ◽  
Tiefeng Li ◽  
Yanju Liu ◽  
Jinsong Leng
Keyword(s):  
Dielectric Constant ◽  
Dielectric Permittivity ◽  
Electric Field ◽  
High Energy ◽  
Dielectric Elastomer ◽  
Dielectric Elastomers ◽  
Polar Group ◽  
Free Energy Function ◽  
Crosslinking Degree ◽  
Structural Symmetry

Dielectric elastomer(DE) is a kind of promising material bearing excellent activate properties including large deformations (up to 380%), high energy densities (up to 3.4 J/g), high efficiency, high responsive speed, good reliability and durability. Thus the DE actuator, sensors and energy harvester is widely used in the field of aeronautics and smart bionics. When an electric field is applied on the compliant electrodes of the dielectric elastomers, the polymer shrinks along the electric field and expands in the transverse plane. In consequence, the electric field becomes higher. This kind of positive feedback may cause the elastomer to thin down, resulting in an electromechanical stability. An analysis on the electromechanical stability of dielectric elastomer using arbitrary free-energy function with constant dielectric constant has been presented in Suo’s papers. In many research on the electromechanical stability analysis of DE actuator, DE’s dielectric constant is assumed to be a constant. This is only the truth if the dielectric elastomer undergoing limited deformation. Actually, a typical dielectric elastomer is a kind of crosslinked polymer. The structural symmetry of the macromolecular, the crosslinking degree, along with the tensile deformation can affect the dielectric permittivity enormously. For dielectric elastomers with higher crosslinking degree, or higher degree of molecular structural symmetry, its permittivity is relatively low. In addition, stretching can guide the macromolecule to be arranged in order, this can increase the intermolecular forces and reduce the activities of polar group, as a results, the dielectric constant will decrease. However, if the crosslinking degree is low and the deformation is well below the extension limit, the molecular units in the polymers can be polarized as freely as in a polymeric liquid. In this case the corresponding permittivity is unaffected by the deformation. Recent experimental research results also proved that the dielectric permittivity of dielectric elastomer changed while undergoing large deformation. According to Pelrine, the dielectric constant of the DE film is variable and it is a function of the area increase ratio which depends on stretch ratio. In this paper, approach for the electromechanical stability of a dielectric elastomer having variable dielectric constant is developed. The critical breakdown electric field is obtained. Simulation results proved that the prestretching process can enhance remarkably the electromechanical stability of dielectric elastomer. These results agree well with the experimental data and can be used as guidances in the design and fabrication of dielectric elastomer actuators.

scholarly journals Multigrid Discretization and Iterative Algorithm for Mixed Variational Formulation of the Eigenvalue Problem of Electric Field

2012 ◽  
Vol 2012 ◽  
pp. 1-25 ◽  
Author(s):  
Yidu Yang ◽  
Yu Zhang ◽  
Hai Bi
Keyword(s):  
Finite Element ◽  
Eigenvalue Problem ◽  
Electric Field ◽  
Adaptive Algorithm ◽  
Variational Formulation ◽  
High Efficiency ◽  
Mixed Finite Element ◽  
Mixed Finite Element Method ◽  
Rayleigh Quotient ◽  
Rayleigh Quotient Iteration

This paper discusses highly finite element algorithms for the eigenvalue problem of electric field. Combining the mixed finite element method with the Rayleigh quotient iteration method, a new multi-grid discretization scheme and an adaptive algorithm are proposed and applied to the eigenvalue problem of electric field. Theoretical analysis and numerical results show that the computational schemes established in the paper have high efficiency.

Modeling and Simulation of the Coupled Mechanical-Electrical Response

2009 ◽  
Author(s):  
Zhan Gao ◽  
Ergin A. Tuncer ◽  
Alberto M. Cuitin˜o
Keyword(s):  
Finite Element ◽  
Closed Form ◽  
Large Deformation ◽  
Electrical Response ◽  
Linear Momentum ◽  
Dielectric Elastomers ◽  
Computational Aspect ◽  
Element Formulation ◽  
Size Change ◽  
Tangent Moduli

Dielectric elastomer (DE) is one type of electro-active polymers (EAP) that responds to electrical stimulation with a significant shape and size change. As EAPs, dielectric elastomers are lightweight, inexpensive, pliable and can be fabricated into various shapes, all of which are attractive properties to justify the intense research in the field. This paper presents a nonlinear, electrical and mechanical coupled, large deformation finite element formulation for DEAs. Maxwell’s equations for the electroquasistatic fields were solved simultaneously with equation of linear momentum. The hyperelastic Ogden model and total Maxwell stress methods were combined to describe the material. The formulation was based on the weak forms of Maxwell’s equation and linear momentum expressed in the reference configuration. The closed form consistent tangent moduli for dielectric elastomers were derived. To our knowledge, the large deformation electric-mechanical coupled finite element application and the closed-form expressions of the tangent moduli have not been reported previously. The results of the simulation have demonstrated the validity of the method from the computational aspect.

scholarly journals Highly Efficient Calculation Schemes of Finite-Element Filter Approach for the Eigenvalue Problem of Electric Field

2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Yu Zhang ◽  
Yidu Yang ◽  
Jie Liu
Keyword(s):  
Finite Element ◽  
Eigenvalue Problem ◽  
Electric Field ◽  
High Efficiency ◽  
Numerical Results ◽  
Linear Algebraic System ◽  
Highly Efficient ◽  
Efficient Calculation ◽  
Interpolation Postprocessing ◽  
Filter Approach

This paper discusses finite-element highly efficient calculation schemes for solving eigenvalue problem of electric field. Multigrid discretization is extended to the filter approach for eigenvalue problem of electric field. With this scheme one solves an eigenvalue problem on a coarse grid just at the first step, and then always solves a linear algebraic system on finer and finer grids. Theoretical analysis and numerical results show that the scheme has high efficiency. Besides, we use interpolation postprocessing technique to improve the accuracy of solutions, and numerical results show that the scheme is an efficient and significant method for eigenvalue problem of electric field.

Large-Deformation Theory of Shells of Revolution

1967 ◽  
Vol 34 (1) ◽  
pp. 56-58 ◽  
Author(s):  
W. Flu¨gge ◽  
S-C. Chou
Keyword(s):  
Internal Pressure ◽  
Large Deformation ◽  
Deformation Theory ◽  
Large Deflection ◽  
Small Strain ◽  
Strain Theory ◽  
Large Strains ◽  
Shells Of Revolution ◽  
Elastic Strains ◽  
Theory Of Shells

In this paper, nonlinear membrane equations are derived for a shell of revolution under the assumption that not only are the displacements and rotations large, but that, also, large strains are admitted. The equations, therefore, are aimed at shells which are not only very thin, but which are also made of a material which permits large elastic strains. The special difficulties resulting from this extension of the theory are discussed. As an example for the application of the equations, a circular toroid subjected to internal pressure is studied. Numerical results are given for a level of loading which lies clearly outside the domain of a large-deflection, small-strain theory.

Simulation Analysis of a Novel Magnetic Gear

2012 ◽  
Vol 490-495 ◽  
pp. 2614-2618
Author(s):  
Yong Kui Man ◽  
Wen Sheng Hao ◽  
Yi Sheng Zhang ◽  
Shuo Zhang ◽  
Jun Feng Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
High Speed ◽  
High Efficiency ◽  
Simulation Analysis ◽  
Peak Torque ◽  
The Novel ◽  
Finite Element Software ◽  
Overload Protection ◽  
Efficient Performance ◽  
Magnetic Gear

Compared with mechanical gear, permanent magnetic gear has unique advantages which are high efficiency, noise free, zero friction, vibrationless, overload protection, etc. This paper introduced a novel coaxial magnetic gear with high speed radio and analyzed the efficient performance including peak torque, starting, braking, and no-loading procedures on the basis of calculating in finite element software Ansoft. The results prove that the novel magnetic gear is reasonable and efficient.

A Finite Element Method for Dielectric Elastomers Affected by Viscoelasticity and Current Leakage

2018 ◽  
Vol 10 (09) ◽  
pp. 1850102 ◽  
Author(s):  
Choon Chiang Foo ◽  
Jun Liu ◽  
Zhi-Qian Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Deformation ◽  
Constitutive Theory ◽  
Dielectric Elastomers ◽  
Simulation Platform ◽  
Current Leakage ◽  
Dissipative Processes ◽  
Finite Element Implementation ◽  
Electromechanical Performance

Dissipative processes such as viscoelasticity and current leakage are known to affect the electromechanical performance of dielectric elastomers. In this work, we describe a constitutive theory that couples electrostatics, large deformation, viscoelasticity and current leakage. We also implement this model in a commercial finite element solver ABAQUS by developing new user-defined elements. The method is used to study the effect of viscoelasticity and current leakage on the behavior of dielectric elastomers. Our finite element implementation will serve as a simulation platform to guide the design of practical dielectric elastomer transducers.

A Novel Spudcan for Easing Spudcan-Footprint Interaction Issues

2016 ◽  
Author(s):  
Minjung Jun ◽  
Youngho Kim ◽  
Muhammad Shazzad Hossain ◽  
Mark Cassidy ◽  
Yuxia Hu ◽  
...  
Keyword(s):  
Finite Element ◽  
Large Deformation ◽  
Soil Conditions ◽  
The Novel ◽  
Clay Layer ◽  
Finite Element Package ◽  
Jack Up

The interaction between a spudcan and an existing footprint is one of the major concerns during jack-up rig installation, especially in the surface clay layer. No guidance was provided in the recently finalised version of ISO guidelines 19905-1 [1] in regards to mitigating spudcan-footprint interaction issues except some proposed considerations due to the lack of detailed investigations. This paper reports a measure for easing spudcan-footprint interaction issues, with the efficiency of a novel spudan shape tested through 3D large deformation finite element (LDFE) analyses. The LDFE analyses using the Coupled Eulerian-Lagrangian (CEL) approach in the commercial finite element package ABAQUS. The soil conditions tested simulate soft seabed strength profiles close to the mudline. A critical reinstallation locations of 0.55D (D = spudcan diameter) and existing footprint depth (of 0.33D) were investigated. The main aim was to investigate if the spudcan shape itself can be used to mitigate potential footprint interaction when compared to a conventional spudcan. The results from this study indicated that the novel spudcan had the potential to ease spudcan-footprint interaction issues.

scholarly journals Soft, tough, and fast polyacrylate dielectric elastomer for non-magnetic motor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Li-Juan Yin ◽  
Yu Zhao ◽  
Jing Zhu ◽  
Minhao Yang ◽  
Huichan Zhao ◽  
...  
Keyword(s):  
High Performance ◽  
Crosslinking Agent ◽  
High Energy ◽  
Dielectric Elastomer ◽  
High Energy Density ◽  
Dielectric Elastomers ◽  
Dielectric Elastomer Actuators ◽  
Response Bandwidth ◽  
Electrically Actuated ◽  
Soft Actuators

AbstractDielectric elastomer actuators (DEAs) with large electrically-actuated strain can build light-weight and flexible non-magnetic motors. However, dielectric elastomers commonly used in the field of soft actuation suffer from high stiffness, low strength, and high driving field, severely limiting the DEA’s actuating performance. Here we design a new polyacrylate dielectric elastomer with optimized crosslinking network by rationally employing the difunctional macromolecular crosslinking agent. The proposed elastomer simultaneously possesses desirable modulus (~0.073 MPa), high toughness (elongation ~2400%), low mechanical loss (tan δm = 0.21@1 Hz, 20 °C), and satisfactory dielectric properties ($${\varepsilon }_{{{{{{\rm{r}}}}}}}$$ ε r  = 5.75, tan δe = 0.0019 @1 kHz), and accordingly, large actuation strain (118% @ 70 MV m−1), high energy density (0.24 MJ m−3 @ 70 MV m−1), and rapid response (bandwidth above 100 Hz). Compared with VHBTM 4910, the non-magnetic motor made of our elastomer presents 15 times higher rotation speed. These findings offer a strategy to fabricate high-performance dielectric elastomers for soft actuators.

Sign in / Sign up

Export Citation Format

Share Document