Short Fiber Reinforcement of Elastomers

1974 ◽  
Vol 47 (5) ◽  
pp. 1074-1081 ◽  
Author(s):  
S. R. Moghe
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Mathematical Model ◽  
Fiber Orientation ◽  
Probability Distribution Function ◽  
Tensile Modulus ◽  
Short Fiber ◽  
Simple Mathematical Model ◽  
Short Fibers ◽  
Rubber Compounds

Abstract Based upon a simple mathematical model, the directional properties of elastomers mixed with uniaxially oriented short fibers are predicted. The model takes into account a probability distribution function for a number of fibers in any direction during fiber orientation. Theory is compared with experimental data on tensile modulus for a number of rubber compounds and fibers with good success. A possibility of characterizing calendering and extrusion processes in view of orientation and mechanical properties is discussed.

Injection molding of short fiber thermoplastic bio-composites: Prediction of the fiber orientation

2020 ◽  
Vol 54 (30) ◽  
pp. 4787-4797
Author(s):  
Fatima-Zahra Semlali AouraghHassani ◽  
Mounir El Achaby ◽  
Mohammed-Ouadi Bensalah ◽  
Denis Rodrigue ◽  
Rachid Bouhfid ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Injection Molding ◽  
Fiber Orientation ◽  
Orientation Angle ◽  
Short Fiber ◽  
Thermoplastic Polymer ◽  
Molded Part ◽  
Practical Tool ◽  
Orientation Pattern

Injection molding of short fiber reinforced thermoplastic polymer results in a preferential fiber orientation in the part, which leads to an anisotropy in the material mechanical properties. To anticipate the molded part performances, it is necessary to predict the fiber orientation pattern. Our goal is to have a practical tool that accurately predicts fiber orientation patterns, and to use that information to estimate the final product properties. Consequently, an efficient way to determine the flow induced fiber orientation for different flow cases under real injection molding conditions is presented. The proposed approach allows the average orientation angle prediction in a section by considering the close interaction between the fibers and the flow rheology, the fibers aspect ratio and the mold geometry. Finally, to validate the model, experimental data were taken with different matrices, fibers and mold geometries, where good agreements (R2 ≥ 0.8) were obtained for the fiber orientations measurements.

Mathematical Model of the Sintering Process of Iron-Copper Bearings

2007 ◽  
Vol 23 ◽  
pp. 119-122
Author(s):  
Cristina Teișanu ◽  
Stefan Gheorghe ◽  
Ion Ciupitu
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Mathematical Model ◽  
Regression Analysis ◽  
Function Optimization ◽  
Chemical Compositions ◽  
Sintering Process ◽  
Molybdenum Disulphide ◽  
Iron Copper ◽  
Antifriction Properties

The most important features of the self-lubricating bearings are the antifriction properties such as friction coefficient and wear resistence and some mechanical properties such as hardness, tensile strength and radial crushing strength. In order to improve these properties new antifriction materials based on iron-copper powders with several additional components (tin, lead and molybdenum disulphide) have been developed by PM techniques. To find the optimal relationship between chemical compositions, antifriction and mechanical properties, in this paper a mathematical model of the sintering process is developed, which highlighted the accordance of the model with data by regression analysis. For the statistical processing of the experimental data the VH5 hardness values of the studied materials were considered. The development of mathematical model includes the enunciation of the model, the establishment of the performance function (optimization) and the establishment of the model equations and verifying. The accordance of the model with experimental data has been highlighted by regression analysis

Robotic Manufacturing of Near-Net Shaped Short-Fiber Reinforced Composites With Functional Properties

2009 ◽  
Author(s):  
Antony Paul ◽  
Jeffery M. Gallagher ◽  
Raymond J. Cipra ◽  
Thomas Siegmund
Keyword(s):  
Mechanical Properties ◽  
Fiber Orientation ◽  
Fiber Composite ◽  
Imaging Techniques ◽  
Short Fiber ◽  
Robotic Arm ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Geometric Data ◽  
Reinforced Composite

Fiber reinforced composite materials are now frequently being used over conventional materials for their ability to achieve tailored properties and performance characteristics. With the recent advancements in manufacturing techniques, short-fiber composites are coming into prominence in this sector, with their cost advantage and their capability for large throughput. Randomness of fiber orientation is inherent to short fiber composite manufacturing processes. In order to effectively manipulate the mechanical properties of a short-fiber reinforced composite, it is imperative to adequately control the orientation of the fibers during the deposition stage. A process is currently developed to acquire geometrical data of the target object and to utilize it to create a short-fiber reinforced component with controlled fiber orientation. The topological data acquisition of the object is made possible using non-contact 3D imaging techniques. The geometric data is then transferred to a commercial CAD package for the added capability to manipulate the geometry as may be required for specific applications. Subsequently, geometric data constitutes the basis of path planning for the tooling processes. In our process, a novel rapidly re-configurable tooling and molding technology is employed by which a 6-axis robotic arm is used to sculpt a pin-device vacuum surface. After the tooling is completed, the robotic arm will use a deposition nozzle to orient a steady stream of initially random short-fiber from a feeder into a unidirectional output, onto the tool surface. By controlling the position and orientation of the deposition nozzle, it is possible to control the orientation and density of fiber in each section of the near-net shaped composite pre-form. The fiber pre-form is then impregnated with a suitable matrix medium and cured to create the required component. The outlined process is thus capable of manufacturing a near-net shaped short-fiber reinforced component with highly specific mechanical properties. One of the many applications envisaged using this process is the manufacture of custom form-fitting braces, masks and guards for use in healthcare products. A patient intervention can have his or her features acquired using stereo-imaging and have corrective measures incorporated into the device prior to manufacturing. By controlling the orientation and density of the fiber at different portions of the device, it is possible to provide adequate support at specific areas or to restrict movement in specific directions while providing compliance to movement in the others.

Dynamics Analysis of Orientation Distribution of Fiber Suspensions in Shear-Extensional Flow

2014 ◽  
Vol 709 ◽  
pp. 168-171
Author(s):  
Pei Fang Luo
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Distribution Function ◽  
Fiber Orientation ◽  
Extensional Flow ◽  
Orientation Distribution ◽  
Dynamics Analysis ◽  
Fiber Suspensions ◽  
Short Fibers ◽  
Uniaxial Extensional Flow

A mathematical model on orientation distribution function of short fibers suspensions in shear-uniaxial extensional flow is established. Furthermore, the result of differential equation on fiber orientation can be obtained.

A Review of Rubber Oxidation

2005 ◽  
Vol 78 (2) ◽  
pp. 355-390 ◽  
Author(s):  
Gui-Yang Li ◽  
J. L. Koenig
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Spatial Distribution ◽  
Oxidative Degradation ◽  
Physical And Mechanical Properties ◽  
Oxidation Products ◽  
Unique Combination ◽  
The Past ◽  
Diffusion Limited ◽  
Rubber Compounds

Abstract The aging of rubber caused by oxidative degradation leads to the deterioration in the physical and mechanical properties of vulcanized rubbers. In an effort to improve the oxidative stability of rubbers and elastomers, considerable amount of work has been carried out over the past 50 years (especially in the most recent 5 years) in order to understand degradation modes and effects in rubber due to the action of oxygen and ozone in the air. Different mechanisms have been proposed to interpret the experimental data relative to the oxidation of rubber. The diffusion limited theory has been widely used in the literature and verified by many experiments. Various instrumental techniques have been utilized to characterize the oxidation and degradation and their mechanisms in rubber compounds. Recently, FTIR imaging has demonstrated a unique combination of spectral and spatial resolution which allows not only the identification of the oxidation products but also their spatial distribution from the oxygen penetrating surfaces. This critical review will cover the major developments in our understanding of the oxidation of rubbers.

scholarly journals Bulk Modulus of Copper Alloys in Context of Modern Metal Theory

2018 ◽  
Vol 1 (1) ◽  
pp. 681-686
Author(s):  
Janusz Chrzanowski ◽  
Bohdan Bieg
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Quantum Theory ◽  
Measurement Error ◽  
Bulk Modulus ◽  
Copper Alloys ◽  
Energy Levels ◽  
Simple Mathematical Model ◽  
Potential Measurement ◽  
Percentage Composition

Abstract The authors used a modern quantum theory allowing to determine the energy levels of electrons in real metal. Based on that analytical equations have been presented by means of which the bulk modulus for chosen metals were calculated. It should be emphasized that all values obtained directly from the derived equation are in perfect conformity with the experimental data, a few percentage differences are comparable with the potential measurement error. Subsequently a simple mathematical model has been proposed which allows to calculate the bulk modulus of copper alloys depending on their percentage composition. The authors performed numerical calculations for the typical copper alloys and the results are presented in the form of graphs.

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