Dynamic Properties of Rubber. Dependence on Pigment Loading

1941 ◽  
Vol 14 (4) ◽  
pp. 842-857 ◽  
Author(s):  
S. D. Gehman ◽  
D. E. Woodford ◽  
R. B. Stambaugh
Keyword(s):  
Zinc Oxide ◽  
Internal Friction ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Modulus Ratio ◽  
Volume Loading ◽  
Static Modulus ◽  
Black Clay ◽  
At Resonance ◽  
Wide Range

Abstract Dynamic properties are specific for different pigments. Curves show the dependence on pigment loading of the dynamic modulus, ratio of dynamic to static modulus, internal friction, dynamic resilience, and calculated relative heat generation at constant force and at constant amplitude. For the same volume loading, the dynamic modulus and internal friction rank in the order: Superspectra, channel black, zinc oxide, clay, blanc fixe, Thermatomic black, i.e., roughly in the order of particle size. The calculated dynamic resilience depends on the ratio of the modulus to the internal friction and increases in the order Superspectra, channel black, clay, Thermatomic black, blanc fixe, zinc oxide. The dynamic modulus shows an almost linear relation with the internal friction for different loadings of the same pigment. The dynamic modulus is independent of the frequency in the range 20–150 cycles per second. It depends on the amplitude, an effect which may be connected with the warming of the test-piece due to the vibration. The amplitude at resonance for the same driving force is approximately constant at all frequencies for a given rubber compound. The results show the wide range of dynamic properties obtainable with different pigments, and bring out the general principles involved in their use for dynamic purposes.

Nonlinearity in the Dynamic Properties of Vulcanized Rubber Compounds

1954 ◽  
Vol 27 (1) ◽  
pp. 209-222 ◽  
Author(s):  
W. P. Fletcher ◽  
A. N. Gent
Keyword(s):  
Simple Shear ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Mechanical Vibration ◽  
Frequency Range ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Chemical Combination ◽  
Wide Range ◽  
Static Shear

Abstract Measurements are described of the dynamic properties of rubber, loaded with various amounts and types of filler, when subjected to mechanical vibration in simple shear at amplitudes from 0 to 3 per cent shear in the frequency range 20 to 120 c.p.s. The decrease of dynamic modulus with increasing amplitude is shown, for a wide range of filler types and concentrations, to be determined by the amount of stiffening produced by the filler. This relationship is not influenced by variations in the vulcanizing ingredients, reasonable variations in state of vulcanization, addition of softener, or imposition of static shear strain. Rubber compounds stiffened by mixture with, or chemical combination of, other polymers exhibit a smaller order of nonlinearity than that described above and also exhibit much lower hysteresis values within the amplitude range 0 to 3 per cent shear.

Some Dynamic Properties of Rubber

1943 ◽  
Vol 16 (1) ◽  
pp. 136-154 ◽  
Author(s):  
C. O. Harris
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Static Strain ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Velocity Coefficient

Abstract The following conclusions apply to rubber of the stock tested when bonded to steel: 1. For cylinders in compression and specimens in shear, the damping can be expressed in terms of a velocity coefficient. The damping decreases with increase of frequency; it increases with increase of static strain. 2. The dynamic modulus of elasticity is slightly larger than the static modulus and is not affected by change of frequency. It increases with increase of static strain for the cylinders and decreases for the shear specimens. 3. For cylinders in compression, both damping and modulus of elasticity are dependent upon the ratio of diameter to length.

Measurement of the Dynamic Modulus of Rubber at Very Small Amplitudes with an Optical Interferometer

1960 ◽  
Vol 33 (2) ◽  
pp. 272-274
Author(s):  
N. M. Borovitskaya
Keyword(s):  
Interference Pattern ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Monochromatic Light ◽  
Michelson Interferometer ◽  
Light Modulation ◽  
Wide Range ◽  
Narrow Band Filter ◽  
The Difference ◽  
Set Up

Abstract A method of measuring very small differences of optical path using light modulation by an interferometer has been described. This enables one to measure amplitudes of mechanical vibrations of the order of 0.01 A or even smaller. We have used this method to measure the dynamic modulus of rubber at very small amplitudes. It is desirable to use this method for measuring the dynamic modulus of rubber and other highly elastic substances, firstly because in accuracy and simplicity it has certain advantages over existing acoustic methods. In the second place, it enables one to work at very small amplitudes and, in association with other methods, over a very wide range of amplitudes of deformation. This is of interest in connection with the general theory of the dynamic properties of rubber, and in particular, for checking the linearity of these properties, that is, the independence of the modulus and the loss on the amplitude, in particular for filled rubbers. We will briefly describe the apparatus with which the measurements were made. It consists of a Michelson interferometer and a source of monochromatic light. The interference pattern (lines of equal width) is projected onto the cathode of a photomultiplier. The output of the photo multiplier is fed to the input of a narrow-band filter, to the output of which the measuring instrument is connected. The mirror on the interferometer is set up so that the whole of the interference pattern, or the greater part of it, is uniformly illuminated. If now one of the mirrors vibrates with a frequency ω and an amplitude of z, then the difference in path between the interference beams will vary with a frequency of ω and the intensity of the light falling on the photomultiplier will also change. The current through the photomultiplier will be modulated with a frequency of ω. The first harmonic of the photocurrent will be I1=AJ1(4τz/λ), where λ is the wavelength of light; A is a coefficient depending on the intensity of the interfering beams and on their difference of path with the mirror at rest; I1 is a first order Bessel function.

The Evaluation of Rubber and Rubberlike Compositions as Vibration Absorbers. Apparatus for Automatic Recording

1937 ◽  
Vol 10 (4) ◽  
pp. 827-833
Author(s):  
Felix L. Yerzley
Keyword(s):  
Internal Friction ◽  
Dynamic Modulus ◽  
Automatic Recording ◽  
Vibration Absorbers ◽  
Dynamic Hardness ◽  
Static Hardness ◽  
Wide Range

Abstract The equipment is simple and foolproof. It provides an autographic record in a few seconds, from which can be evaluated dynamic hardness, dynamic modulus, internal friction, static hardness, and drift. It can be used to test rubber and rubberlike compositions over a very wide range of temperatures—for example, from −40° to 150° C. —for testing compositions which have been exposed to solvents or gases, and in conjunction with a fatigue machine for evaluation at various stages in a life flexing test.

scholarly journals Dynamic Mechanical Properties of Maxillofacial Materials

1975 ◽  
Vol 54 (6) ◽  
pp. 1216-1221 ◽  
Author(s):  
A. Koran ◽  
R.G. Craig
Keyword(s):  
Mechanical Properties ◽  
Internal Friction ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Temperature Range

Six maxillofacial materials were evaluated by determining their dynamic properties with use of a Goodyear Vibrotester. The dynamic modulus, internal friction, and dynamic resilience were measured for all materials over a temperature range of -15 to 37 C. The dynamic modulus ranged from 11.1 to 124.8 kg/cm2 and the dynamic resilience varied from 1.1 to 63.5%.

Wide range modulation of synaptic weight in thin-film transistors with hafnium oxide gate insulator and indium-zinc oxide channel layer for artificial synapse application

Nanoscale ◽  
2021 ◽  
Author(s):  
Keonwon Beom ◽  
Jimin Han ◽  
Hyun-Mi Kim ◽  
Tae-Sik Yoon
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistors ◽  
Hafnium Oxide ◽  
Synaptic Weight ◽  
Drain Current ◽  
Gate Insulator ◽  
Channel Layer ◽  
Indium Zinc Oxide ◽  
Wide Range

Wide range synaptic weight modulation with a tunable drain current was demonstrated in thin-film transistors (TFTs) with a hafnium oxide (HfO2−x) gate insulator and an indium-zinc oxide (IZO) channel layer...

scholarly journals Simulation Verification of the Contact Parameter Influence on the Forces’ Course of Cereal Grain Impact against a Stiff Surface

2021 ◽  
Vol 11 (2) ◽  
pp. 466
Author(s):  
Włodzimierz Kęska ◽  
Jacek Marcinkiewicz ◽  
Łukasz Gierz ◽  
Żaneta Staszak ◽  
Jarosław Selech ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Decisive Role ◽  
Force Sensor ◽  
Contact Forces ◽  
Correct Selection ◽  
Contact Parameter ◽  
Cereal Grain ◽  
Wide Range ◽  
The Impact ◽  
Selection Of

The continuous development of computer technology has made it applicable in many scientific fields, including research into a wide range of processes in agricultural machines. It allows the simulation of very complex physical phenomena, including grain motion. A recently discovered discrete element method (DEM) is used for this purpose. It involves direct integration of equations of grain system motion under the action of various forces, the most important of which are contact forces. The method’s accuracy depends mainly on precisely developed mathematical models of contacts. The creation of such models requires empirical validation, an experiment that investigates the course of contact forces at the moment of the impact of the grains. To achieve this, specialised test stations equipped with force and speed sensors were developed. The correct selection of testing equipment and interpretation of results play a decisive role in this type of research. This paper focuses on the evaluation of the force sensor dynamic properties’ influence on the measurement accuracy of the course of the plant grain impact forces against a stiff surface. The issue was examined using the computer simulation method. A proprietary computer software with the main calculation module and data input procedures, which presents results in a graphic form, was used for calculations. From the simulation, graphs of the contact force and force signal from the sensor were obtained. This helped to clearly indicate the essence of the correct selection of parameters used in the tests of sensors, which should be characterised by high resonance frequency.

Engineering the shape of Zinc Oxide crystals via sonochemical or hydrothermal solution-based methods

2008 ◽  
Vol 1087 ◽  
Author(s):  
Marco Palumbo ◽  
Simon J. Henley ◽  
Thierry Lutz ◽  
Vlad Stolojan ◽  
David Cox ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Good Control ◽  
Transparent Conductors ◽  
Zno Nanostructures ◽  
Large Area ◽  
Light Emitting Devices ◽  
Wide Range ◽  
Solution Methods

AbstractRecent results in the use of Zinc Oxide (ZnO) nano/submicron crystals in fields as diverse as sensors, UV lasers, solar cells, piezoelectric nanogenerators and light emitting devices have reinvigorated the interest of the scientific community in this material. To fully exploit the wide range of properties offered by ZnO, a good understanding of the crystal growth mechanism and related defects chemistry is necessary. However, a full picture of the interrelation between defects, processing and properties has not yet been completed, especially for the ZnO nanostructures that are now being synthesized. Furthermore, achieving good control in the shape of the crystal is also a very desirable feature based on the strong correlation there is between shape and properties in nanoscale materials. In this paper, the synthesis of ZnO nanostructures via two alternative aqueous solution methods - sonochemical and hydrothermal - will be presented, together with the influence that the addition of citric anions or variations in the concentration of the initial reactants have on the ZnO crystals shape. Foreseen applications might be in the field of sensors, transparent conductors and large area electronics possibly via ink-jet printing techniques or self-assembly methods.

Some Dynamic Properties of Rubber

1942 ◽  
Vol 9 (3) ◽  
pp. A129-A135
Author(s):  
C. O. Harris
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Internal Damping ◽  
Standard Practice ◽  
Dynamic Modulus Of Elasticity

Abstract The purpose of the investigation described in this paper was to obtain information concerning the dynamic properties of rubber bonded to metal. Two properties of rubber were measured (a) the internal damping and (b) the dynamic modulus of elasticity. Two types of specimens were tested (a) rubber cylinders bonded to steel cylinders at the ends and stressed in compression and (b) specimens of rubber bonded to steel and stressed in shear. All specimens were of the same stock, 5140-V-4, manufactured by the U. S. Rubber Company. The hardness, as measured by the durometer, varied from 32 to 40. In the process of bonding to the steel, a 1/32-in. layer of 60-durometer stock was added adjacent to each piece of steel. This represents standard practice of the U. S. Rubber Company in bonding soft stock to metal. All specimens were cured for 30 min at 279 F.

What Kind of Friction Model Is Needed to Predict Brake Squeal?

2012 ◽  
Author(s):  
Tore Butlin ◽  
Jim Woodhouse
Keyword(s):  
Large Scale ◽  
Dynamic Properties ◽  
Theoretical Work ◽  
Friction Model ◽  
Coupled Systems ◽  
Brake Squeal ◽  
Model Framework ◽  
Wide Range ◽  
Pin On Disc ◽  
Almost All

Predictive models of friction-induced vibration have proved elusive despite decades of research. There are many mechanisms that can cause brake squeal; friction coupled systems can be highly sensitive to small perturbations; and the dynamic properties of friction at the contact zone seem to be poorly understood. This paper describes experimental and theoretical work aimed at identifying the key ingredients of a predictive model. A large-scale experiment was carried out to identify squeal initiations using a pin-on-disc test rig: approximately 30,000 squeal initiations were recorded, covering a very wide range of frequencies. The theoretical model allows for completely general linear systems coupled at a single sliding point by friction: squeal is predicted using a linearised stability analysis. Results will be presented that show that almost all observed squeal events can be predicted within this model framework, but that some subsets require innovative friction modelling: predictions are highly dependent on the particular choice of friction model and its associated parameters.

Sign in / Sign up

Export Citation Format

Share Document