scholarly journals A Unidirectional Soft Dielectric Elastomer Actuator Enabled by Built-In Honeycomb Metastructures

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 619 ◽  
Author(s):  
Kun Liu ◽  
Shitong Chen ◽  
Feifei Chen ◽  
Xiangyang Zhu
Keyword(s):  
Thermoplastic Polyurethane ◽  
Initial Step ◽  
Dielectric Elastomer ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Inherent Anisotropy ◽  
Dielectric Elastomer Actuators ◽  
Innovative Solution ◽  
Unidirectional Motion

Dielectric elastomer actuators (DEAs) are able to undergo large deformation in response to external electric stimuli and have been widely used to drive soft robotic systems, due to their advantageous attributes comparable to biological muscles. However, due to their isotropic material properties, it has been challenging to generate programmable actuation, e.g., along a predefined direction. In this paper, we provide an innovative solution to this problem by harnessing honeycomb metastructures to program the mechanical behavior of dielectric elastomers. The honeycomb metastructures not only provide mechanical prestretches for DEAs but, more importantly, transfer the areal expansion of DEAs into directional deformation, by virtue of the inherent anisotropy. To achieve uniaxial actuation and maximize its magnitude, we develop a finite element analysis model and study how the prestretch ratios and the honeycomb structuring tailor the voltage-induced deformation. We also provide an easy-to-implement and scalable fabrication solution by directly printing honeycomb lattices made of thermoplastic polyurethane on dielectric membranes with natural bonding. The preliminary experiments demonstrate that our designed DEA is able to undergo unidirectional motion, with the nominal strain reaching up to 15.8%. Our work represents an initial step to program deformation of DEAs with metastructures.

Modeling and experimental verification on directivity of an electret cell array loudspeaker

2012 ◽  
Vol 24 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Yu-Chi Chen ◽  
Wen-Ching Ko ◽  
Han-Lung Chen ◽  
Hsu-Ching Liao ◽  
Wen-Jong Wu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Digital Control System ◽  
Analysis Model ◽  
Cell Array ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
The Finite Element Analysis ◽  
Directivity Characteristics

We propose a model to give us a method to investigate the characteristic three-dimensional directivity in an arbitrarily configured flexible electret-based loudspeaker. In recent years, novel electret loudspeakers have attracted much interest due to their being lightweight, paper thin, and possessing excellent mid- to high-frequency responses. Increasing or decreasing the directivity of an electret loudspeaker makes it excellent for adoption to many applications, especially for directing sound to a particular area or specific audio location. Herein, we detail a novel electret loudspeaker that possesses various directivities and is based on various structures of spacers instead of having to use multichannel amplifiers and a complicated digital control system. In order to study the directivity of an electret loudspeaker based on an array structure which can be adopted for various applications, the horizontal and vertical polar directivity characteristics as a function of frequency were simulated by a finite-element analysis model. To validate the finite-element analysis model, the beam pattern of the electret loudspeaker was measured in an anechoic room. Both the simulated and experimental results are detailed in this article to validate the various assertions related to the directivity of electret cell-based smart speakers.

The Mechanical Mechanism Analysis for Mortar Arch Framework Slope Protection Structure

2013 ◽  
Vol 859 ◽  
pp. 143-148
Author(s):  
Yang Xu ◽  
Ding Ling Li ◽  
Li Peng ◽  
Yan Xiao ◽  
Yi Hua Nie
Keyword(s):  
Finite Element Analysis ◽  
Mechanism Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Vertical Loading ◽  
Total Displacement ◽  
The Finite Element Analysis ◽  
Calculation Results ◽  
Real Scale

The finite element analysis model was built as the real scale for mortar arch framework slope protection, and the displacement and strain at different points were collected by vertical loading pressure. So the mechanical mechanism can be studied, and the analysis was done between calculation results and testing results of solid miniature model. The studying results show that the point on the arch foot is the worst stress place for each arch, and the total displacement increase nonlinear as the distance from the slope top increases, and the bump phenomenon exists in the bottom of slope, the points are likely to be broken.

Wear analysis of eco-friendly non-asbestos friction-lining material applied in an automotive drum brake: Experimental and finite-element analysis

2021 ◽  
pp. 135065012110167
Author(s):  
Dinesh Shinde ◽  
Mukesh Bulsara ◽  
Jeet Patil
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Wear ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Drum Brake ◽  
Wear Analysis ◽  
Lining Material ◽  
Friction Lining

Brake friction lining material is the critical element of a braking system, since it provides friction resistance to the rotating drum for controlling automobiles. The present study involves wear analysis of newly developed eco-friendly non-asbestos friction lining material for automotive drum brake applications using experimental study, finite-element analysis, and microstructural investigations. Theoretical interpretation of braking force at different automobile speeds was derived using fundamentals. Specimen drum brake liner with eco-friendly material compositions was produced using an industrial hot compression molding process at one of the manufacturer. The surface wear of the liner was measured using an effective and accurate method. Furthermore, a finite-element analysis model was developed considering actual operating conditions and various components of the drum brake system. The model was elaborated for various result outcomes, including Von-Mises stresses and total deformation of components of the drum brake, and further used to estimate the surface wear of the friction lining material in terms of transverse directional deformation. Finally, microstructural analysis of the friction lining material was carried out using scanning electron microscopy and energy dispersive spectroscopy. From the results, it is seen that the developed friction lining material is wear resistant. The finite-element analysis model can be effectively utilized to study the tribological characteristics of friction lining materials.

Detailed Stress Analysis of a Spherical Acrylic Submersible by 3-D Finite Element Modeling

1999 ◽  
Author(s):  
Partha S. Das
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Dissimilar Materials ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
New Model ◽  
Ocean Exploration ◽  
Near Future ◽  
First Time

Abstract Harbor Branch Oceanographic Institution (HBOI) designed, built and has operated two JOHNSON-SEA-LINK (JSL) manned submersibles for the past 25 years. The JSL submersibles each incorporate a 66–68 in. (1.6764–1.7272 m) OD, 4–5.25 in. (0.1016–0.13335 m) thick acrylic two-man sphere as a Pressure Vessel for Human Occupancy (PVHO). This type of spherical acrylic sphere or submersible was first introduced in around 1970 and is known as Naval Experimental Manned Observatory (NEMO) submersibles. As the demand increases for ocean exploration to 3000 ft. (914.4 m) depth to collect samples, to study the ocean surfaces, the problem of developing cracks at the interface of these manned acrylic submersibles following few hundred dives have become a common phenomena. This has drawn considerable attentions for reinvestigation of the spherical acrylic submersible in order to overcome this crack generation problem at the interface. Therefore, a new full-scale 3-D nonlinear FEA (Finite Element Analysis) model, similar to the spherical acrylic submersible that HBOI uses for ocean exploration, has been developed for the first time in order to simulate the structural behavior at the interface and throughout the sphere, for better understanding of the mechanical behavior. Variation of the stiffness between dissimilar materials at the interface, lower nylon gasket thickness, over designed aluminum hatch are seemed to be few of the causes for higher stresses within acrylic sphere at the nylon gasket/acrylic interface. Following the basic understanding of the stresses and relative displacements at the interface and within different parts of the submersible, various models have been developed on the basis of different shapes and thickness of nylon gaskets, openings of the acrylic sphere, hatch geometry and its materials, specifically to study their effect on the overall performance of the acrylic submersible. Finally, the new model for acrylic submersible has been developed by redesigning the top aluminum hatch and hatch ring, the sphere openings at both top and bottom, as well as the nylon gasket inserts. Altogether this new design indicates a significant improvement over the existing spherical acrylic submersible by reducing the stresses at the top gasket/acrylic interface considerably. Redesigning of the bottom penetrator plate, at present, is underway. In this paper, results from numerical modeling only are reported in details. Correlation between experimental-numerical modeling results for the new model will be reported in the near future.

Construction Monitoring on Steel Truss Bridge’s Maintenance and Reinforcement

2018 ◽  
Vol 878 ◽  
pp. 89-94 ◽  
Author(s):  
Er Lei Wang
Keyword(s):  
Simulation Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Construction Monitoring ◽  
Finite Element Analysis Model ◽  
Bridge Steel ◽  
Steel Truss ◽  
Stress And Deformation ◽  
Site Test

Implementing monitoring over construction process of old bridge’s reinforcement serves as an important measure to ensure construction quality and safety and realize the goal of reinforcement. This paper, with a case study of the maintenance and reinforcement project of Zhicheng Yangtze River Bridge (steel truss highway-railway combined bridge), adopted MIDAS to establish finite element analysis model, and with stress and deformation as monitoring parameters, completed the construction monitoring work, numerical simulation analysis and site test for the reinforcement project.

scholarly journals DIELECTRIC ELASTOMER ACTUATOR: NEXT GENERATION FUNCTIONAL MATERIALS FOR INNOVATIVE ROBOTICS

2017 ◽  
Keyword(s):  
Large Scale ◽  
Functional Materials ◽  
Dielectric Elastomer ◽  
Element Analysis ◽  
Promising Alternative ◽  
Robotic Arms ◽  
Soft Actuator ◽  
Computational Dynamics ◽  
Dielectric Elastomer Actuators ◽  
Human Muscles

Conventional actuators based on metal and ceramics face challenges in utilizing them for service and welfare robots, which should work cooperatively with human workers. Dielectric elastomer actuators (DEAs) are a promising alternative to the conventional hard actuators, because they can realize motions which more resemble those of human muscles. Our research aimed at developing a DEA for applications in handling robotic arms and gripper hands for service/welfare robots. To this end, the elements of soft actuator ought to be fabricated and integrated into a large-scale array. Design of the actuator need to be optimized using computational dynamics and Finite Element Analysis (FEA). The application of DEA in robotics is expected to create a drive for the practical realization of reliable and functional DEAs. It could also promote commercialization and tap into the vast potential service/welfare robotic market

scholarly journals Finite element analysis of T-joint of mechanical connecting channels

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402097774
Author(s):  
Jiawei Wang ◽  
Fachao Li ◽  
Zibo Chen ◽  
Baishu Li ◽  
Jue Zhu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Rail Transit ◽  
Force Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Before And After ◽  
Design Software

This paper studies the force and deformation of the connecting channel in Ningbo rail transit construction, which firstly used the mechanical shield method. Steel-concrete composite structural segments are used in the T-joint of connecting channel. The cutting part of the segments are replaced by the concrete and fiberglass instead of reinforced concrete. Basing on a variety of three-dimensional design software and ABAQUS finite element analysis software, a refined finite element analysis model of the special segments is established. By considering the influence of curved joint bolts, the force analysis of the special segments under the structural state before and after construction is performed. According to the analysis and comparison of the deformation of the segments with and without the bolts, it is concluded that the steel-concrete segments can withstand the pressure of the soil before and after the construction. Suggestions for the safety of the design and construction of the segments are put forward.

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