scholarly journals Shell-Forming Stimulus-Active Hydrogel Composite Membranes: Concept and Modeling

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 541 ◽  
Author(s):  
Adrian Ehrenhofer ◽  
Thomas Wallmersperger
Keyword(s):  
Finite Element ◽  
Composite Membranes ◽  
Bending Stiffness ◽  
Dead Weight ◽  
Flexible Displays ◽  
Temperature Expansion ◽  
Hydrogel Composite ◽  
Drastic Increase ◽  
Shell Forming ◽  
Expansion Model

The swelling of active hydrogels combined with passive layers allows the design of shell-forming structures. A shell-like structure offers different properties than a flat structure, e.g., variations in bending stiffness across different directions. A drastic increase of the bending stiffness is favorable e.g., in rollable/flexible displays: in their unrolled form, they have to be stiff enough to resist bending due to dead weight. At the same time, they have to be flexible enough to be rolled-up. This can be achieved by shell-forming. In the current modeling and simulation work, we present a basic concept of combined active–passive composites and demonstrate how they form shells. As the example material class, we use hydrogels with isotropic swelling capabilities. We demonstrate how to model the combined mechanical behavior with the Temperature-Expansion-Model. Afterwards, we show numerical results obtained by Finite Element simulations. We conclude that the envisioned structure has a great potential for obtaining soft rollable sheets that can be stiffened by intrinsic activation.

Interaction Between Wire and Ingot in Wiresaw Slicing

1999 ◽  
Author(s):  
Fuqian Yang ◽  
J. C. M. Li ◽  
Imin Kao
Keyword(s):  
Finite Element ◽  
Contact Zone ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Bending Stiffness ◽  
Mechanical Interaction ◽  
Wire Tension ◽  
Cutting Zone ◽  
The Wire

Abstract The deformation of the wire in the wiresaw slicing process was studied by considering directly the mechanical interaction between the wire and the ingot. The wire tension on the upstream is larger than on the downstream due to the friction force between the wire and the ingot. The tension difference across the cutting zone increases with friction and the span of the contact zone. The pressure in the contact zone increases from the entrance to the exit if the wire bending stiffness is ignored. The finite element results show that the wire bending stiffness plays an important role in the wire deformation. Higher wire bending stiffness (larger wire size) generates higher force acting onto the ingot for the same amount of wire deformation, which will leads to higher material removal rate and kerf loss. While larger wire span will reduce the force acting onto the ingot for a given ingot displacement in the direction perpendicular to the wire.

Fabric-hydrogel composite membranes for culturing microalgae in semipermeable membrane-based photobioreactors

2015 ◽  
Vol 54 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Seung-Yong Lee ◽  
Z-Hun Kim ◽  
Hwa Yeon Oh ◽  
Younghoon Choi ◽  
Hanwool Park ◽  
...  
Keyword(s):  
Composite Membranes ◽  
Semipermeable Membrane ◽  
Hydrogel Composite

Finite Element Analysis of Ground Imitating Tank

2005 ◽  
Author(s):  
Jiemin Liu ◽  
Guangtao Ma
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Dead Weight ◽  
Element Analysis ◽  
Thin Walled ◽  
The Dead ◽  
Stress And Deformation ◽  
Inertia Forces ◽  
Element Method

A typical ground imitating tank is analyzed regarding it as the thin-walled structure composed of plates (skins) and beams (reinforcement) using finite element method (FEM). Through moving the location of reinforcements, make the skins close with the flanges of the reinforcements in order to imitate actually the connection of the skins and the reinforcements. The thickness of plates, the size and the geometry shape and the location of reinforcements are taken as parameters to be optimized. In calculation, not only consider effects of the oil-weight, the extra-pressure in tank and the dead weight of the tank on the stresses and displacements of the tank, but also analyze the effects of the inertia forces produced due to the rotation of the tank on the stresses and displacements. Displacement, stress and deformation distributions of the ground imitating tank under the three typical flying postures imitated are given.

Nanofibrous hydrogel composite membranes with ultrafast transport performance for molecular separation in organic solvents

2019 ◽  
Vol 7 (33) ◽  
pp. 19269-19279 ◽  
Author(s):  
Yi Li ◽  
Eric Wong ◽  
Alexander Volodine ◽  
Chris Van Haesendonck ◽  
Kaisong Zhang ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Interfacial Polymerization ◽  
Composite Membranes ◽  
Hydrogel Composite ◽  
Molecular Separation ◽  
Solvent Permeation

A polyamide (PA) nanofilm was successfully fabricated on the nanofibrous hydrogel support via controlled interfacial polymerization (IP) and exhibited an unprecedented solvent permeation for various organic solvents.

scholarly journals Direct influence of residual stress on the bending stiffness of cantilever beams

2012 ◽  
Vol 468 (2145) ◽  
pp. 2595-2613 ◽  
Author(s):  
M. X. Shi ◽  
B. Liu ◽  
Z. Q. Zhang ◽  
Y. W. Zhang ◽  
H. J. Gao
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Cantilever Beam ◽  
Intermolecular Forces ◽  
Bending Stiffness ◽  
Direct Influence ◽  
Theoretical Predictions ◽  
Calculation Results ◽  
Geometry Nonlinearity ◽  
First Time

Although the cantilever beam has been widely used as a sensor to measure various physical quantities, important issues such as how residual stress affects its bending stiffness and what are the underlying physical origins have not been fully understood. We perform both theoretical analyses and finite-element simulations to demonstrate for the first time that without changing the material tangent stiffness, residual stress within the beam can directly influence the bending stiffness of the beam. This direct influence arises from two origins: geometry nonlinearity and Poisson’s ratio effect. For a cantilever beam with adsorbed macromolecules on its surfaces, we find that longer macromolecular chains have lower normal stiffness and larger intermolecular forces, which makes the effect of the residual stress more pronounced. The excellent agreement between our theoretical predictions and finite-element calculation results validate our analysis. The present work provides an important framework for improving the sensitivity of a cantilever beam as a sensor.

Simulation Research of a Type of Pressure Vessel under Complex Loading Part 1 Component Load of the Numerical Analysis

2013 ◽  
Vol 756-759 ◽  
pp. 4656-4661
Author(s):  
Yu Fu Zhang ◽  
Hui Xia Guo ◽  
Jun Chen Li ◽  
Gui Rong Yang ◽  
Ying Ma ◽  
...  
Keyword(s):  
Finite Element ◽  
Pressure Vessel ◽  
Geometric Modeling ◽  
Mechanical Response ◽  
Complex Loading ◽  
Strain Response ◽  
The Finite Element Method ◽  
Key Factors ◽  
Dead Weight ◽  
Simulation Research

Macroscopic mechanical response is one of the key factors in designing pressure vessel. A geometric modeling of pressure vessel was established and the mesh of this modeling then generated by using the finite element simulating methods in software ABAQUS. Loading and boundary conditions of dead weight, hydraulic and uniform internal pressure which often suffered pressure vessel were set and calculated by the finite element method. Stress/strain response of pressure vessel in all kinds of alone loading ways were obtained. The results of finite element simulating were in accordance with those of theoretical calculation which provided useful data for research on mechanical response of pressure vessel under complex loading conditions.

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