scholarly journals Development and testing of controlled adaptive fiber-reinforced elastomer composites

2016 ◽  
Vol 88 (3) ◽  
pp. 345-353 ◽  
Author(s):  
Chokri Cherif ◽  
Rico Hickmann ◽  
Andreas Nocke ◽  
Matthias Schäfer ◽  
Klaus Röbenack ◽  
...  
Keyword(s):  
Smart Materials ◽  
Longitudinal Direction ◽  
Loop Control ◽  
Elastomeric Matrix ◽  
Control Automation ◽  
Glass Fiber Reinforcement ◽  
Flow Through ◽  
Elastomer Composites ◽  
Set Up ◽  
High Deformability

The integration of shape memory alloys (SMAs) into textile-reinforced composites produces a class of smart materials whose shape can be actively influenced. In this paper, Ni-Ti SMA wires are inserted during the weaving of a glass fiber reinforcement textile. This “active” reinforcement is then combined with an elastomeric matrix to produce a highly flexible composite sheet, which maintains high rigidity in the longitudinal direction. By activating the SMAs, high deflection ratios of up to 35% (relative to the component's length) are achieved. To adjust the composite's deflection to defined values, a closed-loop control is set up to adjust the current flow through the SMA wires. A control algorithm is designed and evaluated for several test cases. The high deformability and the controllable behavior show the high potential of these materials for applications such as aerodynamic flow control, automation and architecture.

scholarly journals Magneto-Rheological Elastomer Composites. A Review

2020 ◽  
Vol 10 (14) ◽  
pp. 4899 ◽  
Author(s):  
Sneha Samal ◽  
Marcela Škodová ◽  
Lorenzo Abate ◽  
Ignazio Blanco
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Mechanical Response ◽  
Viscoelastic Behavior ◽  
Shear Mode ◽  
Dynamic Shear ◽  
Elastomeric Matrix ◽  
Elastomer Composites ◽  
Magneto Rheological ◽  
Micro Structures

Magneto-rheological elastomer (MRE) composites belong to the category of smart materials whose mechanical properties can be governed by an external magnetic field. This behavior makes MRE composites largely used in the areas of vibration dampers and absorbers in mechanical systems. MRE composites are conventionally constituted by an elastomeric matrix with embedded filler particles. The aim of this review is to present the most outstanding advances on the rheological performances of MRE composites. Their distribution, arrangement, wettability within an elastomer matrix, and their contribution towards the performance of mechanical response when subjected to a magnetic field are evaluated. Particular attention is devoted to the understanding of their internal micro-structures, filler–filler adhesion, filler–matrix adhesion, and viscoelastic behavior of the MRE composite under static (valve), compressive (squeeze), and dynamic (shear) mode.

Studying changes in the electrical resistance of carbon-nanotubes-modified elastomers during their compression, stretching and torsion

2019 ◽  
pp. 128-138
Author(s):  
V. S. Yagubov ◽  
A. V. Shchegolkov ◽  
A. V. Shchegolkov ◽  
N. R. Memetov
Keyword(s):  
Composite Material ◽  
Smart Materials ◽  
Electrical Resistance ◽  
Materials Science ◽  
Measuring System ◽  
Constant Current ◽  
Matrix Composition ◽  
Space Industry ◽  
Different Types ◽  
Elastomer Composites

Developing "smart" materials with improved both structural and functional characteristics is one of the promising areas of materials science. Measuring the electrical resistance of CNTs-modified (various mass contents) polymers and in particular, elastomers during performing several tests (compression, stretching, and torsion) at a constant current is relevant in electrical engineering, mechanical engineering, aviation, and space industry. Changes in the elastomer shape under different types of testing lead to the destruction of macromolecules and the structuring of the material as a whole. Therefore, it is important to study the effect of CNTsbased modifying fillers on the elastomer. When compressing, stretching or twisting the nano-modified elastomer, along with the mutual movement of its macromolecular fragments and aggregates, the modifier particles also move, which generally determines the transport of electrons in the resulting structure and affects the physical and mechanical parameters of the composite material. To conduct studies, elastomers containing different amounts of a CNTs-based modifying filler were prepared. To investigate and elucidate relevant dependencies, a measuring system (MS) was constructed, which makes it possible to determine electrical resistance values of the composite material with different CNTs contents in the polymer matrix composition exposed to various mechanical loads. Basing the research results, it was established that the electrical resistance of the elastomer composites modified with 1.0–2.5 wt.% CNTs decreases when compressing from 0 to 100 N, whereas when the compression force ranges from 100 to 350 N, the electrical resistance remains unchanged. When the elastomer composites modified with 2–2.5 wt.% CNTs were stretched by 30–40 %, the electrical resistance was found to increase from 5·103 to 1.9·107 Ω.

scholarly journals Development of Liquid Diene Rubber Based Highly Deformable Interactive Fiber-Elastomer Composites

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 390
Author(s):  
Vikram G. Kamble ◽  
Johannes Mersch ◽  
Muhammad Tahir ◽  
Klaus Werner Stöckelhuber ◽  
Amit Das ◽  
...  
Keyword(s):  
Low Temperature ◽  
Research Topic ◽  
Artificial Limbs ◽  
Phase Transformation Temperature ◽  
Elastomeric Matrix ◽  
Intelligent Structures ◽  
Polybutadiene Rubber ◽  
Elastomer Composites ◽  
Vulcanization Process ◽  
Diene Rubber

The preparation of intelligent structures for multiple smart applications such as soft-robotics, artificial limbs, etc., is a rapidly evolving research topic. In the present work, the preparation of a functional fabric, and its integration into a soft elastomeric matrix to develop an adaptive fiber-elastomer composite structure, is presented. Functional fabric, with the implementation of the shape memory effect, was combined with liquid polybutadiene rubber by means of a low-temperature vulcanization process. A detailed investigation on the crosslinking behavior of liquid polybutadiene rubber was performed to develop a rubber formulation that is capable of crosslinking liquid rubber at 75 °C, a temperature that is much lower than the phase transformation temperature of SMA wires (90–110 °C). By utilizing the unique low-temperature crosslinking protocol for liquid polybutadiene rubber, soft intelligent structures containing functional fabric were developed. The adaptive structures were successfully activated by Joule heating. The deformation behavior of the smart structures was experimentally demonstrated by reaching a 120 mm bending distance at an activation voltage of 8 V without an additional load, whereas 90 mm, 70 mm, 65 mm, 57 mm bending distances were achieved with attached weights of 5 g, 10 g, 20 g, 30 g, respectively.

scholarly journals Investigation on the Mechanical Properties of MRE Compounds

Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
Renato Brancati ◽  
Giandomenico Di Massa ◽  
Stefano Pagano
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Smart Materials ◽  
Testing Machine ◽  
Static Test ◽  
Vibration Isolators ◽  
Elastomeric Matrix ◽  
Magneto Rheological ◽  
Stiffness And Damping ◽  
Rheological Effect

This paper describes an experimental investigation conducted on magneto-rheological elastomers (MREs) with the aim of adopting these materials to make mounts to be used as vibration isolators. These materials, consisting of an elastomeric matrix containing ferromagnetic particles, are considered to be smart materials, as it is possible to control their mechanical properties by means of an applied magnetic field. In the first part of the paper, the criteria adopted to define the characteristics of the material and the experimental procedures for making samples are described. The samples are subjected to a compressive static test and are then, adopting a testing machine specially configured, tested for shear periodic loads, each characterized by a different constant compressive preload. The testing machine is equipped with a coil, with which it is possible to vary the intensity of the magnetic field crossing the sample during testing to evaluate the magneto-rheological effect on the materials’ characteristics in terms of stiffness and damping.

Platelet Aggregometry and Shape Change Measurement by Laser Light in Small Samples

1979 ◽  
Author(s):  
P. Blasberg ◽  
L.J. Wurzinper
Keyword(s):  
Hollow Fiber Membrane ◽  
Shape Change ◽  
Scattered Light ◽  
Transmitted Light ◽  
Small Samples ◽  
Change Measurement ◽  
Platelet Aggregometry ◽  
Space Angle ◽  
Flow Through ◽  
Set Up

A technique is presented to measure platelet aggregation (PA) and platelet shape change (PSC) with high accuracy in small samples (100 ul) using a turbidimetric method wich a He-Ne-Laser as light source. Both, transmitted and scattered light, Is measured by two independent light sensitive elements. Transmitted light is detected by a photodiode with a sensitive area of 1 mm2 covering a space angle of Ω= 0.004 sterad. Scattered light is detected by a photoelement surrounding the photodiode which covers a space angle of U-1.4 sterad. Ar, electronic set up forms a signal, which is proportional to the ratio scattered light/scattered light + transmitted light.The output voltage is linearly correlated to the turbidity of the suspension. The whole set up is employed with three different types of cuvettes.1. A cuvette where through a semipermeable hollow fiber membrane different drugs can diffuse into the platelet suspensions avoiding any stirring of the sample ()2. A flow through cuvette to measure the extent of PA in PRP samples.3. A couette type platelet aggregometer.

Free Zone Electrophoresis of Clotting Factors

1979 ◽  
Author(s):  
T. Cartwright ◽  
C.H. Dickerson ◽  
D.E.G. Austen
Keyword(s):  
Factor Viii ◽  
Total Yield ◽  
Solid Matrix ◽  
Clotting Factors ◽  
Free Zone ◽  
Zone Electrophoresis ◽  
Flow Apparatus ◽  
Electrophoresis System ◽  
Flow Through ◽  
Set Up

A free-zone electrophoresis system is used for rapid production of substantially purified factor VIII from either citrated plasma or from a factor VIII Concentrate of intermediate purety. Using concentrate, a total yield of 43% of clotting activity is obtained with fibrinogen reduced to approximately 30% of its starting level. Protein level is reduced to 20% of the original value. Using plasma, the albumin, factor VIII and fibrinogen were all separated from factor VIII. In these experiments, factor-VIII-related antigen migrates with the coagulant factor VIII illustrating that both have similar mobilities equivalent to that of an alpha-globulin, or else that they are connected together. The particular advantage of this separation is that it is carried out in a continuous flow apparatus in liquid buffer with no solid matrix and that once the apparatus is set up, material can flow through the machine at a rate of 5 mls/min being continuously separated. The main problem and area for further study is that of concentrating the relatively dilute fractions without undue loss.

scholarly journals The High Energy Materials Science Beamline (HEMS) at PETRA III

2013 ◽  
Vol 772 ◽  
pp. 57-61 ◽  
Author(s):  
Norbert Schell ◽  
Andrew King ◽  
Felix Beckmann ◽  
Torben Fischer ◽  
Martin Müller ◽  
...  
Keyword(s):  
Smart Materials ◽  
Materials Science ◽  
High Energy ◽  
Test Facility ◽  
Polycrystalline Materials ◽  
Energy Materials ◽  
Friction Stir ◽  
Materials Research ◽  
Set Up

The HEMS beamline at PETRA III has a main energy of 120 keV, is tunable in the range 30-200 keV, and optimized for sub-micrometer focusing with Compound Refractive Lenses. Design, construction, and main funding was the responsibility of the Helmholtz-Zentrum Geesthacht, HZG. Approximately 70 % of the beamtime is dedicated to Materials Research, the rest reserved for “general physics” experiments covered by DESY, Hamburg. The beamline P07 in sector 5 consists of an undulator source optimized for high energies, a white beam optics hutch, an in-house test facility and three independent experimental hutches, plus additional set-up and storage space for long-term experiments. HEMS has partly been operational since summer 2010. First experiments are introduced coming from (a) fundamental research for the investigation of the relation between macroscopic and micro-structural properties of polycrystalline materials, grain-grain-interactions, recrystallisation processes, and the development of new & smart materials or processes; (b) applied research for manufacturing process optimization benefitting from the high flux in combination with ultra-fast detector systems allowing complex and highly dynamic in-situ studies of microstructural transformations, e.g. in-situ friction stir welding; (c) experiments targeting the industrial user community.

scholarly journals Impact of Component Dispersion in DC to DC Low-Power Low-Voltage Power Converter Array

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 917
Author(s):  
Jean-Christophe CREBIER ◽  
Theo LAMORELLE ◽  
Silvain MARACHE ◽  
Thanh Hai PHUNG ◽  
Van-Sang NGUYEN ◽  
...  
Keyword(s):  
Closed Loop ◽  
Low Voltage ◽  
Power Converter ◽  
Point Of View ◽  
Statistical Point ◽  
Loop Control ◽  
In Series ◽  
And Performance ◽  
Set Up ◽  
The Impact

The paper deals with arrays of numerous power conversion cells, associated in series and/or in parallel to build larger step up or step down direct current (DC)/DC isolated converters. The work focuses on the impact of the spread and distribution of the conversion cell characteristics on the characteristics and performance of the power converter array (PCA). Based on a characterization protocol, about 130 conversion standard cells (CSC) are characterized and classified from a statistical point of view. Three families are defined and representatives are chosen and implemented in various configurations, in open and closed loop control, to analyze the impact of their spread characteristic over the global converter, the PCA. The paper is based on an extended practical set up and protocols, all described in details. Guidelines on CSCs implementation with respect to their dispersion are provided at the end on the paper.

Microstructure and Mechanical Properties of X80/X100 High Deformability Pipeline Steel

2011 ◽  
Vol 399-401 ◽  
pp. 139-143
Author(s):  
Dian Xiu Xia ◽  
De Liang Meng ◽  
Shou Yong An ◽  
Yong Lin Kang
Keyword(s):  
Pipeline Steel ◽  
Large Strain ◽  
High Strength ◽  
Longitudinal Direction ◽  
Granular Bainite ◽  
Dual Phase ◽  
Cooling Process ◽  
Bainite Structure ◽  
Lath Bainite ◽  
High Deformability

In the present study, X80 and X100 grade high deformability pipeline steels have been processed by using TMCP and followed two-stage cooling process. The microstructures of the X80HD (HD, high deformability) and X100HD steels were both characterized by ferrite-bainite dual phase. The grains sizes of ferrite were mostly less than 5μm and the volume fractions were about 20~25% in X80HD and 10~15% in X100HD steel. The bainite structure in X80HD steel was granular bainite (GB); while in X100HD steel large amounts of lath bainite (LB) were also formed besides GB, and bainite grains were much finer. Ferrite-bainite dual phase microstructure has large strain hardenability that resulting high strength and high deformability combination. Both the steels exhibit high strength/toughness in transverse direction and high deformability in longitudinal direction. The X100HD steel with more volume of LB and less volume of PF has higher strength but lower deformability than that of X80HD steel.

scholarly journals Vibration Control of Double-Beam System with Multiple Smart Damping Members

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Dominik Pisarski ◽  
Tomasz Szmidt ◽  
Czesław I. Bajer ◽  
Bartłomiej Dyniewicz ◽  
Jacek M. Bajkowski
Keyword(s):  
Smart Materials ◽  
Closed Loop ◽  
Control Method ◽  
Bilinear System ◽  
Element Model ◽  
Strong Wind ◽  
Loop Control ◽  
Double Beam ◽  
Bang Bang Control ◽  
Wind Blow

A control method to stabilize vibration of a double cantilever system with a set of smart damping blocks is designed and numerically evaluated. The externally controlled magnetorheological sheared elastomer damping block is considered, but other smart materials can be used as well. The robust bang-bang control law for stabilization the bilinear system is elaborated. The key feature of the closed loop controller is the efficiency for different types of initial excitement. By employing the finite element model, the performance of the controller is validated for strong wind blow load and concentrated impact excitement of the particular point of one of the beams. For each of the excitations, the closed loop control outperforms the optimal passive damping case by over 27% for the considered energy metric.

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