scholarly journals The Visco-Elastic Behavior of PA+PAI Composites with Fiber Glass after UV Degradation

2018 ◽  
Vol 47 (4) ◽  
pp. 329-334
Author(s):  
Tatiana Liptáková ◽  
Lenka Markovičová ◽  
Viera Zatkalíková ◽  
Dušan Gaňa
Keyword(s):  
Automotive Industry ◽  
Polymeric Composite ◽  
Complex Viscosity ◽  
Elastic Behavior ◽  
Atmospheric Conditions ◽  
Uv Degradation ◽  
Fiber Glass ◽  
Rheological Measurements ◽  
Glass Fibres ◽  
Moduli Of Elasticity

The polymeric composites on the base of the PA+PAI filled by glass fibres are usually used in automotive industry and also exposed to natural atmosphere. The research is focused on resistance study of the mentioned composites in simulated atmospheric conditions. The tested specimens contented 10, 20 and 30 % of the glass fibres and they were exposed in UV box with defined time and intensity of UV radiation and temperature. The mentioned factors have a considerable influence on utility and lifetime of product made of the polymeric composite. The effect of the exposition on the composites behaviour was evaluated microscopically, by rheological measurements and impact tests. By the rheological measurements the changes of visco-elastic parameters (complex viscosity, moduli of elasticity and plasticity) were studied after different times of exposition in the UV box as well as chosen mechanical properties.

Effect of Heat Sinks on Visco-Elastic & Mechanical Properties of EPDM Based Ablative Composites

2010 ◽  
Vol 442 ◽  
pp. 52-58
Author(s):  
M.A. Bashir ◽  
H. Ahmad ◽  
R. Ahmed ◽  
R.A. Alvi ◽  
Mohammad Bilal Khan
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Glass Fiber ◽  
Heat Sinks ◽  
Elastic Behavior ◽  
Fiber Glass ◽  
Adverse Conditions ◽  
Reinforcing Fillers ◽  
Heat Shielding ◽  
Reinforcing Filler

Ablative composites are heat shielding, protective materials that are being used in aerospace industry to protect inner hardware and sensitive devices. The aero dynamic vehicles have to face high stresses, ultra high temperature and adverse conditions of air friction. It is required to develop the materials with light weight and high modulus. EPDM, being heat and ozone attack resistant is the best candidate for the preparation of ablative composites by introducing different heat sinks such as silica, glass fiber, carbon fiber, asbestos, carbon and their combinations have been studied in this work. The prepared materials were tested and it was found that visco elastic behavior of the composites affected by the addition of reinforcing filler (carbon, silica), semi-reinforcing filler (carbon fiber, glass fiber) and non-reinforcing filler (asbestos powder). Mechanical properties tested at different rates, revealed the improvement in tensile strength and % elongation in case of reinforcing and semi-reinforcing fillers but showed adverse effect in case of non-reinforcing fillers. Rheological investigations of these novel composites shows that moony viscosity of the materials containing glass fiber, carbon fiber, silica decreases in the order glass fiber > carbon fiber > silica.

scholarly journals Characterisation of glass fibres used in automotive industry for SMC body panels

2006 ◽  
Vol 37 (10) ◽  
pp. 1536-1544 ◽  
Author(s):  
V. Feuillade ◽  
A. Bergeret ◽  
J.-C. Quantin ◽  
A. Crespy
Keyword(s):  
Automotive Industry ◽  
Glass Fibres

Biomimetic study of a polymeric composite material for joint repair applications

2007 ◽  
Vol 22 (6) ◽  
pp. 1632-1639 ◽  
Author(s):  
Rahul Ribeiro ◽  
Poulomi Ganguly ◽  
Donald Darensbourg ◽  
Meitin Usta ◽  
A. Hikmet Ucisik ◽  
...  
Keyword(s):  
Composite Material ◽  
Polymeric Composite ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Elastic Behavior ◽  
Experimental Investigations ◽  
Polymeric Composite Material ◽  
Multiwalled Carbon ◽  
Atomic Force ◽  
Joint Repair

A longer lifespan is still being sought for biomaterials used for joint repair. We developed a new nanocomposite material of polytrimethylene carbonate (PTMC), hydroxyapatite (HAP), and multiwalled carbon nanotubes (MWNT) to mimic real cartilage. Experimental results were compared with those of natural cartilage and the conventional joint replacement material ultrahigh-molecular-weight polyethylene (UHMWPE). Friction experiments showed that our developed composite material had a coefficient of friction close to that of articular cartilage. Nanoindentation experiments indicated that the surface elastic behavior was similar to that of cartilage. The surface attraction forces on a silicon atomic force microscope tip were much higher for cartilage than those for the other two materials. These results hold promise for this artificial cartilage composite material’s performance in vivo, following further experimental investigations and chemical modifications.

Microrheology study of semidiluted deoxyribonucleic acid solutions

2010 ◽  
Vol 1277 ◽  
Author(s):  
F. Carvajal ◽  
J. G. Alvarez ◽  
E.R. Macías ◽  
V.V.A. Fernández ◽  
E. Robles-Avila ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Sodium Salt ◽  
Viscoelastic Properties ◽  
Deoxyribonucleic Acid ◽  
Complex Viscosity ◽  
Elastic Behavior ◽  
Acid Solutions ◽  
Plateau Modulus ◽  
Calf Thymus

Linear rheological behavior and Microrheology measurements of sodium salt calf-thymus DNA aqueous solutions as a function of concentration are reported here. The microrheological behavior was obtained by a combination of experimental techniques: mechanical Rheometry and Dynamic light scattering (DLS). The viscoelastic properties of DNA in water as a function of concentration were performed at 20 °C and rheological and microrhelogical curves were performed. The result indicated that for concentrations lower than the entanglement concentration (Ce) the system exhibits a predominantly viscous behavior, whereas for higher concentrations exhibits a predominantly elastic behavior. The plateau modulus (G0) and the zero complex viscosity () follow a power law concentration dependence of the form: and , respectively The microrheology results overlap perfectly in a single line with the mechanical rheology results, extending the time resolution to faster breathing modes

Research Regarding Design and Material for an Electrical Car Charger Shell

2019 ◽  
Vol 56 (3) ◽  
pp. 488-491
Author(s):  
Catalin Marin Buciuman ◽  
Liana Hancu ◽  
Cristian Vilau ◽  
Cristina Stefana Miron Borzan
Keyword(s):  
Composite Material ◽  
Electric Vehicles ◽  
Automotive Industry ◽  
Feasible Solution ◽  
Sheet Steel ◽  
Polymeric Composite ◽  
Extreme Conditions ◽  
Charging Infrastructure ◽  
The World ◽  
Electrical Vehicle

In the recent years, the electric vehicles have drawn great attention worldwide as a feasible solution for clean transportation. The charging infrastructure for electric vehicles is expanding throughout the world, encouraged by large investments from the automotive industry, to reduce carbon emissions. The purpose of this paper is to design the shell of an electrical vehicle charger by using polymeric composite materials. The manufacturing technology is proposed and the analysis of the product behaviour during the wind action in extreme conditions is presented. The paper includes studies and research regarding the design, the manufacturing and the simulation for the action of wind upon the product�s walls. The simulations are performed for the actual used material (ordinary sheet steel) and for the proposed composite material in order to compare the results. The composite material seems to be an adequate solution for the electric charger shell.

scholarly journals Modeling of Mechanical Properties of the Polymeric Composite Reinforced with Braided Preform

2021 ◽  
Vol 1199 (1) ◽  
pp. 012007
Author(s):  
A Kondratiev ◽  
O Andrieiev ◽  
A Tsaritsynskyi ◽  
T Nabokina
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
High Speed ◽  
Experimental Studies ◽  
Polymeric Composite ◽  
Structural Behavior ◽  
Elastic Behavior ◽  
Design Parameters ◽  
Polymeric Composite Materials ◽  
Reinforcement Angle

Abstract Braided composite structures based on preforms are widely used in various industries. Owing to use of such preforms high speed and efficiency of the process of manufacturing of polymeric composite materials and structures on their basis can be provided. Knowledge of their properties in the design allows optimizing the production of structures with the specified parameters. The paper gives the review of three approaches to the description of physical and mechanical characteristics of the composite with braided fixtures – based on the classical theory of layered media, rod-based model, and the method of polynomial approximation. The necessary estimated dependencies were derived in order to predict the elastic and structural behavior of the composites under study at any reinforcement angle according to the known characteristics of predetermined angles. Synthesized design parameters, as distinct from the existing ones, allow predicting strength characteristics of the composite based on the braided hoses depending on the positioning and location of the material on the shape-generating surface. For the verification of theoretical results, a number of experimental studies have been carried out with the formation of samples of the material with the different reinforcing angles. Comparison of the analytical and experimental results allows drawing the conclusions that rod-based model gives the best results for the description of elastic behavior of the polymeric composite materials, whereas the obtained polynomial dependences are recommended for the structural behavior. The results of the work represent the basis for solving the problems of calculation of strength of the structures made of composite materials based on the braided preforms

Modelling the Seepage of Groundwater: Application of the Viscous Analogy and Numerical Methods

1999 ◽  
Vol 9 (4) ◽  
pp. 165-171
Author(s):  
Ekaterina D. Krusteva ◽  
Stefan Y. Radoslavov ◽  
Zdravko I. Diankov
Keyword(s):  
Mathematical Models ◽  
Quantitative Comparison ◽  
Test Method ◽  
Two Dimensional ◽  
Atmospheric Conditions ◽  
Flow Discharge ◽  
Rheological Measurements ◽  
Factors Influencing ◽  
Horizontal Drainage ◽  
Model Fluid

Abstract The application of the viscous analogy, known as the Hele-Show model, for seepage investigation is demonstrated in the paper. The changes in the viscous properties of the model fluid (glycerine) resulting from the changes of the atmospheric conditions - temperature and humidity, have been taken under consideration as factors influencing the flow discharge in the model. A method has been substantiated for the exact quantitative comparison of discharges obtained under different boundary conditions of the seepage process using parallel rheological measurements of the model fluid. The results from the viscous and mathematical models are compared for a particular two-dimensional seepage process - the operation of a horizontal drainage. The complete coincidence of these results, proves the good grounds of the method as well as its applicability as a test method for the development of mathematical models.

INTERNAL FRICTION OF FINE‐GRAINED LIMESTONES AT ULTRASONIC FREQUENCIES

Geophysics ◽  
1959 ◽  
Vol 24 (2) ◽  
pp. 285-296 ◽  
Author(s):  
Louis Peselnick ◽  
Isidore Zietz
Keyword(s):  
Internal Friction ◽  
Ultrasonic Pulse ◽  
Atmospheric Conditions ◽  
Complex Moduli ◽  
Fine Grained ◽  
Three Samples ◽  
Solid Friction ◽  
Different Grain Size ◽  
Moduli Of Elasticity ◽  
Made In

Ultrasonic pulse measurements in the 3 to 10 mc/sec frequency range were made of shear and dilatational absorption and velocity for three samples of fine grained, homogeneous, and well compacted limestones at atmospheric conditions. The complex moduli of elasticity were calculated for two limestone specimens of different grain size and porosity. A “hysteresis” or “solid‐friction” type of loss for waves of dilatation was found in all three limestone specimens. Shear measurements made in one of the limestones also show a “hysteresis” type of loss. Comparison of the dilatational loss in a single crystal of calcite to the dilatational loss in the limestones indicates that the internal friction for the limestone specimens probably occurs at the grain boundaries.

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