Scar-Like Self-Reinforced and Failure-Tolerant Dielectric Elastomer Actuator With AgNWs Electrode

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Mingqi Zhang ◽  
Yuhan Xie ◽  
Tingge Yao ◽  
Xunuo Cao ◽  
Zhen Zhang ◽  
...  

Scar structures of natural animals can reinforce the wounds both mechanically and biologically to maintain the functions of the injured muscle and skin. Inspired by the scar structure, we present a dielectric elastomer (DE) with silver nanowire electrodes possessing the scar-like ability. This DE membrane can tolerate the failures by both electric breakdown and mechanical rupture. The DE actuator (DEA) can maintain their performances of force and displacement output after multiple failures. Scanning electronic microscope (SEM) images show that the scar-like structures accumulate around the electromechanical failure locations on the DE membrane as the stiffened and insulated regions, which prevent further short current and membrane rupture. J-integrals and stress distribution around the failure location have been calculated by finite element analysis to verify the mechanical reinforcements of the scar-like structures over crack propagation.

Author(s):  
Giovanni Berselli ◽  
Rocco Vertechy ◽  
Gabriele Vassura ◽  
Vincenzo Parenti Castelli

The interest in actuators based on dielectric elastomer films as a promising technology in robotic and mechatronic applications is increasing. The overall actuator performances are influenced by the design of both the active film and the film supporting frame. This paper presents a single-acting actuator which is capable of supplying a constant force over a given range of motion. The actuator is obtained by coupling a rectangular film of silicone dielectric elastomer with a monolithic frame designed to suitably modify the force generated by the dielectric elastomer film. The frame is a fully compliant mechanism whose main structural parameters are calculated using a pseudo-rigid-body model and then verified by finite element analysis. Simulations show promising performance of the proposed actuator.


2009 ◽  
Vol 131 (4) ◽  
Author(s):  
H. F. Wang ◽  
Z. F. Sang ◽  
L. P. Xue ◽  
G. E. O. Widera

The burst pressure of cylinders with hillside nozzle is determined using both experimental and finite element analysis (FEA) approaches. Three full-scale test models with different angles of the hillside nozzle were designed and fabricated specifically for a hydrostatic test in which the cylinders were pressurized with water. 3D static nonlinear finite element simulations of the experimental models were performed to obtain the burst pressures. The burst pressure is defined as the internal pressure for which the structure approaches dimensional instability, i.e., unbounded strain for a small increment in pressure. Good agreement between the predicted and measured burst pressures shows that elastic-plastic finite element analysis is a viable option to estimate the burst pressure of the cylinders with hillside nozzles. The preliminary results also suggest that the failure location is near the longitudinal plane of the cylinder-nozzle intersection and that the burst pressure increases slightly with an increment in the angle of the hillside nozzle.


2009 ◽  
Vol 1 (3) ◽  
Author(s):  
Giovanni Berselli ◽  
Rocco Vertechy ◽  
Gabriele Vassura ◽  
Vincenzo Parenti Castelli

The interest in actuators based on dielectric elastomer films as a promising technology in robotic and mechatronic applications is increasing. The overall actuator performances are influenced by the design of both the active film and the film supporting frame. This paper presents a single-acting actuator, which is capable of supplying a constant force over a given range of motion. The actuator is obtained by coupling a rectangular film of silicone dielectric elastomer with a monolithic frame designed to suitably modify the force generated by the dielectric elastomer film. The frame is a fully compliant mechanism whose main structural parameters are calculated using a pseudo-rigid-body model and then verified by finite element analysis. Simulations show promising performance of the proposed actuator.


2015 ◽  
Vol 37 (9) ◽  
pp. 862-869 ◽  
Author(s):  
Jinxing Huo ◽  
Per Dérand ◽  
Lars-Erik Rännar ◽  
Jan-Michaél Hirsch ◽  
E. Kristofer Gamstedt

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Christopher J. Evans ◽  
Timothy F. Miller

This paper investigates using nonlinear finite element analysis (FEA) to determine the failure pressure and failure location for pressure vessels. The method investigated by this paper is to predict the pressure-vessel failure point by identifying the pressure and location where the total mechanical strain exceeds the actual elongation limit of the material. A symmetrically shaped component and a nonsymmetric shaped component are analyzed to determine the failure pressure and location. Data were then gathered by testing each pressure vessel to determine its actual failure pressure. Comparing the FEA results with experimental data showed that the fea software predicted the failure pressure and location very well for the symmetric shaped pressure vessel, however, for the nonsymmetrical shaped pressure-vessel, the fea software predicted the failure pressure within a reasonable range, but the component failed at a weld instead of the predicted location. This difference in failure location was likely caused by varying material properties in both the weld and the location where the vessel was predicted to fail.


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