scholarly journals Wrapping Liquids, Solids, and Gases in Thin Sheets

2019 ◽  
Vol 10 (1) ◽  
pp. 431-450 ◽  
Author(s):  
Joseph D. Paulsen
Keyword(s):  
Recent Progress ◽  
Geometric Model ◽  
Thin Sheet ◽  
Nonlinear Problems ◽  
Small Scale ◽  
Thin Sheets ◽  
Interfacial Film ◽  
Metal Foils ◽  
High Flexibility ◽  
Significant Attention

Many objects in nature and industry are wrapped in a thin sheet to enhance their chemical, mechanical, or optical properties. Similarly, there are a variety of methods for wrapping, from pressing a film onto a hard substrate to inflating a closed membrane, to spontaneously wrapping droplets using capillary forces. Each of these settings raises challenging nonlinear problems involving the geometry and mechanics of a thin sheet, often in the context of resolving a geometric incompatibility between two surfaces. Here, we review recent progress in this area, focusing on highly bendable films that are nonetheless hard to stretch, a class of materials that includes polymer films, metal foils, textiles, and graphene, as well as some biological materials. Significant attention is paid to two recent advances: a novel isometry that arises in the doubly-asymptotic limit of high flexibility and weak tensile forcing, and a simple geometric model for predicting the overall shape of an interfacial film while ignoring small-scale wrinkles, crumples, and folds.

scholarly journals Visual Simulation of Detailed Turbulent Water by Preserving the Thin Sheets of Fluid

Symmetry ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 502 ◽  
Author(s):  
Jong-Hyun Kim ◽  
Wook Kim ◽  
Young Kim ◽  
Jung Lee
Keyword(s):  
Turbulent Flows ◽  
Visual Simulation ◽  
Numerical Dissipation ◽  
Small Scale ◽  
Thin Sheets ◽  
Global Flow ◽  
Low Mass ◽  
The Difference ◽  
Water Simulation ◽  
Turbulent Water

When we perform particle-based water simulation, water particles are often increased dramatically because of particle splitting around breaking holes to maintain the thin fluid sheets. Because most of the existing approaches do not consider the volume of the water particles, the water particles must have a very low mass to satisfy the law of the conservation of mass. This phenomenon smears the motion of the water, which would otherwise result in splashing, thereby resulting in artifacts such as numerical dissipation. Thus, we propose a new fluid-implicit, particle-based framework for maintaining and representing the thin sheets and turbulent flows of water. After splitting the water particles, the proposed method uses the ghost density and ghost mass to redistribute the difference in mass based on the volume of the water particles. Next, small-scale turbulent flows are formed in local regions and transferred in a smooth manner to the global flow field. Our results show us the turbulence details as well as the thin sheets of water, thereby obtaining an aesthetically pleasing improvement compared with existing methods.

Characterization of Tensile and Compressive Behavior of Microscale Sheet Metals Using a Transparent Micro-Wedge Device

2011 ◽  
Author(s):  
James Magargee ◽  
Jian Cao ◽  
Rui Zhou ◽  
Morgan McHugh ◽  
Damon Brink ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Thin Sheet ◽  
Thin Sheets ◽  
Stainless Steel Sheet ◽  
Sheet Metals ◽  
Compressive Behavior ◽  
Buckling Modes ◽  
Full Field ◽  
Compressive Loads

The cyclic and compressive mechanical behavior of ultra-thin sheet metals was experimentally investigated. A novel transparent wedge device was designed and fabricated to prevent the buckling of thin sheets under compressive loads, while also allowing full field strain measurements of the specimen using digital imaging methods. Thin brass and stainless steel sheet metal specimens were tested using the micro-wedge device. Experimental results show that the device can be used to delay the onset of early buckling modes of a thin sheet under compression, which is critical in examining the compressive and cyclic mechanical behavior of sheet metals.

scholarly journals Experimental and Numerical Study for the Shaping Formation of SCST Structures by Cable-tensioning

2013 ◽  
Vol 7 (1) ◽  
pp. 77-83
Author(s):  
J.W. Kim ◽  
J. H. Doh ◽  
S. Fragomeni
Keyword(s):  
Numerical Study ◽  
Geometric Model ◽  
Small Scale ◽  
Element Analysis ◽  
Construction Technique ◽  
Construction Methods ◽  
Space Truss ◽  
Test Models ◽  
Scale Test ◽  
Joint Behaviour

This paper discusses the behaviour characteristics of the shaping formation of Single-Chorded Space Truss (SCST) structures by means of cable-tensioning of bottom chords. The innovative technique is fast and economical and issued in many types of space structures. The small-scale test models presented herein consist of uniform pyramids with multi-directional ball type joints which are erected into their final shape by cable-tensioning. Since the joint behaviour is very significant in studying the shaping of SCST structures, basic tests for beam and pyramidal units were performed. The feasibility of the proposed cable-tensioning technique and the reliability of the established geometric model were confirmed by finite element analysis. The proposed cable-tensioning technique indicates that the behaviour characteristic of joints is very important in the shaping formation of SCST structures. More specifically in situations where heavy cranes are inaccessible, the cable-tensioning construction technique has proven to be an easy and reasonable method compared to conventional construction methods that typically include heavy cranes and scaffolding.

scholarly journals Biomedical applications of dendritic fibrous nanosilica (DFNS): recent progress and challenges

RSC Advances ◽  
2020 ◽  
Vol 10 (61) ◽  
pp. 37116-37133
Author(s):  
Mina Shaban ◽  
Mohammad Hasanzadeh
Keyword(s):  
Biomedical Applications ◽  
Recent Progress ◽  
Complex Structures ◽  
Significant Attention

Dendritic fibrous nanosilica (DFNS) , with multi-component and hierarchically complex structures, has recently been receiving significant attention in various fields of nano-biomedicine.

Shape-changing polymers for biomedical applications

2019 ◽  
Vol 7 (10) ◽  
pp. 1597-1624 ◽  
Author(s):  
Alina Kirillova ◽  
Leonid Ionov
Keyword(s):  
Biomedical Applications ◽  
Recent Progress ◽  
Smart Polymers ◽  
Shape Morphing ◽  
Shape Transformations ◽  
Biomedical Field ◽  
External Stimuli ◽  
Significant Attention

Smart polymers that are capable of controlled shape transformations under external stimuli have attracted significant attention in the recent years due to the resemblance of this behavior to the biological intelligence observed in nature. In this review, we focus on the recent progress in the field of shape-morphing polymers, highlighting their most promising applications in the biomedical field.

The Influence of Shielding Gas on Strength of the Laser Welded Thin Sheet Lap Welds

2018 ◽  
Vol 786 ◽  
pp. 98-103 ◽  
Author(s):  
Markku Keskitalo ◽  
Aappo Mustakangas ◽  
Mikko Hietala ◽  
Kari Mäntyjärvi
Keyword(s):  
Energy Input ◽  
Thin Sheet ◽  
Thin Plates ◽  
Thin Sheets ◽  
Laser Weld ◽  
Shielding Gas ◽  
Corrosion Properties ◽  
Weld Joints ◽  
Gas Nozzle ◽  
Better Than

The laser welding is usable method for joining thin plates with low energy input and precise penetration control. When joining of very thin sheets such as 0.5 mm the shape of the weld must be complete in order to achieve a good strength of the joint. The part of the test welds were welded without shielding gas and other part of the test welds by using 65 mm shielding gas nozzle behind the key hole. The strength of the laser weld of 0.5 mm Austenitic stainless steel (ASS) plate was measured in welds without shielding gas and Ar shielded weld. The strength of the shielded weld joints was significantly better than the joint weld without shielding gas due to convex shielded welds. In addition the shielded welds were bright which improves the corrosion properties of the joint.

A Model for Analyzing Multi-Asperity Contact of Thin Sheets With Real Surfaces on Both Sides

2005 ◽  
Author(s):  
John J. Jagodnik ◽  
Sinan Mu¨ftu¨
Keyword(s):  
Thin Sheet ◽  
Beam Theory ◽  
Contact Problems ◽  
Elastic Half Space ◽  
Asperity Contact ◽  
Thin Sheets ◽  
Bending Rigidity ◽  
Bernoulli Beam ◽  
Substrate Rigidity ◽  
Euler Bernoulli Beam

A model for two-sided contact of a thin sheet of material, with real surfaces on both sides is presented. The model combines cylindrical-contact equations, with Euler-Bernoulli beam theory to examine the importance of substrate rigidity in two-sided contact problems. A finite difference program for solving this model is developed. Results for two-sided contact of numerically generated surfaces on thin tapes are presented. The effects of tape thickness and tension are explored. It is shown that substrate’s bending rigidity contributes significantly to the overall equilibrium, for typical tape thicknesses and tension values used by the industry. However, large thickness values exists for which substrate bending is negligible and elastic half-space solutions applied to both sides of the tape are adequate.

scholarly journals Recent Progress in Thermoelectric Materials Based on Conjugated Polymers

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 107 ◽  
Author(s):  
Chang-Jiang Yao ◽  
Hao-Li Zhang ◽  
Qichun Zhang
Keyword(s):  
Thermal Conductivity ◽  
Energy Harvesting ◽  
Conjugated Polymers ◽  
Recent Progress ◽  
Inorganic Compounds ◽  
Lead Telluride ◽  
Practical Applications ◽  
Tin Selenide ◽  
Properties Of Materials ◽  
High Flexibility

Organic thermoelectric (TE) materials can directly convert heat to electricity, and they are emerging as new materials for energy harvesting and cooling technologies. The performance of TE materials mainly depends on the properties of materials, including the Seebeck coefficient, electrical conductivity, thermal conductivity, and thermal stability. Traditional TE materials are mostly based on low-bandgap inorganic compounds, such as bismuth chalcogenide, lead telluride, and tin selenide, while organic materials as promising TE materials are attracting more and more attention because of their intrinsic advantages, including cost-effectiveness, easy processing, low density, low thermal conductivity, and high flexibility. However, to meet the requirements of practical applications, the performance of organic TE materials needs much improvement. A variety of efforts have been made to enhance the performance of organic TE materials, including the modification of molecular structure, and chemical or electrochemical doping. In this review, we summarize recent progress in organic TE materials, and discuss the feasible strategies for enhancing the properties of organic TE materials for future energy-harvesting applications.

scholarly journals From climatological to small scale applications: Simulating water isotopologues with ICON-ART-Iso (version 2.1)

2017 ◽  
Author(s):  
Johannes Eckstein ◽  
Roland Ruhnke ◽  
Stephan Pfahl ◽  
Emanuel Christner ◽  
Christoph Dyroff ◽  
...  
Keyword(s):  
Water Cycle ◽  
Global Network ◽  
Small Scale ◽  
Seasonal Cycles ◽  
Flexible Tool ◽  
Modelling Framework ◽  
Daily Cycles ◽  
High Flexibility ◽  
Water Isotopologues ◽  
Δd And Δ18o

Abstract. We present the new isotope enabled model ICON-ART-Iso. The physics of the global ICOsahedral Nonhydrostatic (ICON) modelling framework have been extended to simulate passive moisture tracers and the stable isotopologues HDO and H218O. The extension builds on the infrastructure provided by ICON-ART, which allows a high flexibility with respect to the number of related water tracers that are simulated. The physics of isotopologue fractionation follow the model COSMOiso. First, we present a detailed description of the physics of fractionation that have been implemented in the model. The model is then evaluated by comparing with measurements in precipitation and vapor representing a range of temporal scales. A multi annual simulation is compared to observations of the isotopologues in precipitation taken from the station network GNIP (Global Network for Isotopes in Precipitation). ICON-ART-Iso is able to reasonably simulate the seasonal cycles in δD and δ18O as observed at the GNIP stations. In a comparison with IASI satellite retrievals, the seasonal and daily cycles in the isotopologue content of vapor are examined for different regions in the free troposphere. On a small spatial and temporal scale, ICON-ART-Iso is used to simulate the period of two flights of the IAGOS-CARIBIC aircraft in September 2010, which sampled air in the tropopause level influenced by Hurricane Igor. The general features of this sample as well as all of tropical data available from IAGOS-CARIBIC are captured by the model. The study demonstrates that ICON-ART-Iso is a flexible tool to analyze the water cycle of ICON. It is capable of simulating tagged water as well as the isotopologues HDO and H218O.

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