Hysteresis and Reinforcement

1932 ◽  
Vol 5 (3) ◽  
pp. 336-350
Author(s):  
H. Barron ◽  
F. H. Cotton
Keyword(s):  
Internal Friction ◽  
Potential Energy ◽  
Tensile Properties ◽  
Hysteresis Loss ◽  
Breaking Point ◽  
Vulcanized Rubber ◽  
Extension Work ◽  
Rubber Filler

Abstract 1. The relationships between work of extension, work of retraction, and hysteresis loss in vulcanized rubbers loaded with fillers have been examined. 2. The hysteresis loss in vulcanized rubber during a cycle of extension and retraction increases with amplitude to an extent comparable with the increase in work of extension. 3. If the work required to extend a vulcanized rubber to a given elongation be increased by compounding with fillers, the energy lost through hysteresis on slow retraction increases to a comparable extent. Hence reinforcement does not appreciably increase the ability of rubber to store energy. 4. With any rubber vulcanized to optimum tensile properties, hysteresis loss and work of retraction from any elongation are proportional to the work required to extend to that elongation. Therefore if the hysteresis loss during a given cycle be known, the work of retraction from the breaking point can be calculated. 5. The work of retraction from the ultimate breaking point of a vulcanized rubber increases slightly with reinforcement, and becomes greatest when reinforcement is at a maximum. This is thought to be a function of the rubber-filler interface. 6. No filler was found to lessen the work of retraction from the breaking point until the rubber was highly compounded. 7. It is suggested that the increased work required to rupture rubber that has been reinforced with fillers is mainly dissipated in overcoming consequent increased internal friction; a small quantity being converted to potential energy through strain of the filler-rubber interface.

The Hysteresis of Vulcanized Rubber

1949 ◽  
Vol 22 (4) ◽  
pp. 1000-1008 ◽  
Author(s):  
Jacques Clouaire
Keyword(s):  
Internal Friction ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Experimental Work ◽  
Extensive Investigation ◽  
Recovery Curves ◽  
Vulcanized Rubber ◽  
Long Time ◽  
Underlying Causes ◽  
The Subject

Abstract The present paper is based on an extensive investigation of the tensile properties of vulcanized natural rubber, carried out at the French Rubber Institute from April 1944 to December 1946. The purpose of this paper is to show how, in problems such as hysteresis, the correlation of certain experimental facts which apparently bear no relation to one another may lead to an explanation of the phenomenon involved. The hysteresis effect shown by both natural rubber and synthetic rubbers after stretching has been recognized for a long time, and it can be defined as the nonsuperposition of the strain and recovery curves of one complete cycle of deformation. It should be noted that this definition makes no reference to the causes of the phenomenon nor to the idea of loss of energy, which is not so clearly defined as generally believed. As a matter of fact, although the literature on the elasticity of rubber is remarkably extensive, little information is to be found on the underlying causes of hysteresis. The only real experimental work on the subject was carried out by Bouasse, who succeeded in throwing light on some of the complexities of the phenomenon. However, it appears that since that time little attention has been paid to his work. This may account for the fact that the idea of hysteresis being due solely to internal friction is still so widely accepted, although actually so completely incorrect.

Tensile Properties and Dynamic Mechanical Behaviour of Natural Rubber Compound Filled with Rice Husk Silica Produced via Solvent-Thermal Extraction Method

2019 ◽  
Vol 947 ◽  
pp. 195-199
Author(s):  
Zainathul Akhmar Salim Abdul Salim ◽  
Aziz Hassan ◽  
Hanafi Ismail ◽  
Nor Hafizah Che Ismail
Keyword(s):  
Natural Rubber ◽  
Tensile Properties ◽  
Rice Husk ◽  
Mechanical Behaviour ◽  
Extraction Method ◽  
Silica Content ◽  
Rice Husk Silica ◽  
Dynamic Mechanical ◽  
Thermal Extraction ◽  
Rubber Filler

This study highlighted the effect of incorporation of rice husk silica (RHS) on the tensile properties and dynamic mechanical behaviour of natural rubber (NR) compounds. High purity RHS was synthesised by solvent-thermal extraction method, which was inspired by TAPPI T204 cm-97 and TAPPI T264 cm-97 standards with some modifications. The extraction method had successfully produced RHS with 99.9% of silica content and surface area of 234.25 m2/g. The incorporation of RHS in NR showed increment in tensile properties compared to unfilled NR. Further improvement was recorded by surface modification of RHS with 1 wt. % bis (triethoxysilylpropyl) tetrasulfide (TESPT). The modification of RHS with TESPT increased the rubber-filler interaction between RHS and NR matrix, hence enhancing the strength-related properties. The modified RHS-NR also recorded highest storage modulus, and the presence of RHS in the NR compound had slightly shifted the glass transition temperature (Tg) to a higher value. This confirmed that the strong rubber-filler interaction had increased the rigidity of the compounds and restricted the mobility of the rubber chains.

scholarly journals The power transmission stability and efficiency of V-belts

2016 ◽  
Vol 12 (1) ◽  
pp. 25-49
Author(s):  
László Kátai ◽  
Péter Szendrő ◽  
Péter Gárdonyi
Keyword(s):  
Internal Friction ◽  
Food Industry ◽  
Power Transmission ◽  
Angular Displacement ◽  
Hysteresis Loss ◽  
Damping Factor ◽  
Belt Drive ◽  
Agricultural Machinery ◽  
Plate Structure ◽  
Belt Drives

The V-belt drive is a rather popular, widely used form of power transmission in agricultural and food industry engineering. At the same time, its stability, the lifetime of V-belt is influenced by several environmental factors, namely in the food industry by the contamination affecting the belt sides, the ambient temperature, humidity and the occasionally aggressive (acidic, alkaline air, air saturated with gases, etc.) medium. In the case of agricultural machinery, the vibration caused by uncertainly oriented pulleys with bearing in different plate structures (often being shaken in the fields) as well as alignment adjustment inaccuracies jeopardize the reliability of the parameters of the drive. Furthermore, the efficiency is determined by several factors together: the slippage occurring during drive transmission, the hysteresis loss resulting from the external and internal friction occurring with the belt entering and exiting the pulley. Experimental equipment and calculation methods were developed to determine the dynamics of temperature increase generated by the belt and pulley relationship. The temperature generated in the V-belt was measured as a function of pretension, pulley diameter and bending frequency. The so-called damping factor characterizing the contact with the pulley (the external friction when entering and exiting the groove) and the hysteresis loss (inner friction) are also determined. On the basis of the damping factor (ζ ≈ 400 Ns/m2) of the V-belt involved in the experiments the other losses (Poth) occurring from the pulley—V-belt contact and internal friction may be estimated. The drive parameters may be optimized with the mathematical model describing the effect of the pulley diameter and belt frequency on the increase in temperature. A standardized calculation method as well as design factors valid for the properly adjusted drive and normal operating conditions determined through empirical and laboratory experiments are used for the sizing of V-belt drives. The lifetime of V-belt drives designed in this way, used in extreme conditions typical of agricultural machinery will not be appropriate and will not provide clear, predictable information for maintenance planning. In such cases the results of our own many lifetime tests conducted in the given circumstances can be safely relied on. The agricultural harvesting machines are large plate-body self-propelled structures on which most of the power supply of the (threshing, cleaning, moving, etc.) machine units handling the crop is realized via belt drives. The distance and angular displacement of the axes involved in the drive can vary within wide limits. The misalignment and angular displacement of the pulleys can be the result of installation instability — due to the plate structure — and the deformation of the plate structure occurring during the operation as well. V-belt drives operate satisfactorily under such conditions as well, however these faults are unfavourable in terms of belt lifetime and result in the reduction of drive efficiency. A further aim of our research is to examine through experiments the lifetime and efficiency of V-belts used in agricultural machines as a function of drive adjustment errors. According to the results of the measurements of the geometrical adjustment errors of V-belt drives performed in the field, the pulleys of agricultural equipment are not always positioned in the medium plane of the drive. In our experiments these data served as independent variables. Figure 1 shows the arrangement of a V-belt drive in a grain harvester with the laser pulley alignment measuring instrument installed as an accessory. In the case of many machine types in 80% of the tested drives three times the permissible error was measured, and because of off-road use, due to dynamic load these errors further increased as a result of the frame deformation. The results of both the belt bending testing and the geometrical adjustment testing of the drive offer great help in the design of belt drives. At the same time they can be the source of lifetime and efficiency forecasts.

CARPENTER HYMU 80 ALLOY

Alloy Digest ◽  
1989 ◽  
Vol 38 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Initial Permeability ◽  
Hysteresis Loss ◽  
Magnetic Alloy ◽  
Soft Magnetic ◽  
Soft Magnetic Alloy ◽  
Maximum Permeability

Abstract CARPENTER HyMu 80 alloy is an unoriented soft magnetic alloy with extremely high initial permeability as well as maximum permeability with minimum hysteresis loss. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: Ni-375. Producer or source: Carpenter.

Effect of Temperature on Tensile Properties of Vulcanized Rubber

1934 ◽  
Vol 7 (2) ◽  
pp. 371-386
Author(s):  
A. A. Somerville ◽  
W. F. Russell
Keyword(s):  
High Temperature ◽  
Tensile Properties ◽  
Room Temperature ◽  
Point Of View ◽  
Effect Of Temperature ◽  
Curing Conditions ◽  
Vulcanized Rubber ◽  
Before And After ◽  
Temperature Test ◽  
Better Than

Abstract The tensile properties and tear resistance of a large number of commercial inner tubes, before and after aging by different methods, are studied at 0°, 25°, and 100° C. A number of uncured bus-truck tube stocks are also studied from the point of view of their capacity to withstand high temperatures. The effect of testing rubber at 100° C. as compared with room temperature is discussed; how some compounds collapse at 100° C., while others have tensile properties equal to, or better than those at 25°, is shown. The effect of testing artificially aged specimens at 100° C., as well as at 25° C., is discussed; the high-temperature test may reveal conditions of deterioration and overcure that are not noticeable in the 25° tests. The compounding and curing conditions that lead to high tensile properties at 100° C., as well as those which cause inferior quality, are discussed.

The Oxidation Products of Rubber

1939 ◽  
Vol 12 (2) ◽  
pp. 225-234
Author(s):  
A. van Rossem ◽  
P. Dekker
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Tensile Properties ◽  
High Speed ◽  
Accelerated Aging ◽  
Direct Determination ◽  
Oxidation Products ◽  
Vulcanized Rubber

Abstract In their summary of the aging of vulcanized rubber, Porritt and Scott state that three factors are responsible for the changes in mechanical properties of vulcanized rubber during aging, viz.: (a) oxidation of the rubber; (b) after-vulcanization; (c) some colloidal change of the rubber, sometimes termed aggregation. Of these factors, oxidation is by far the most important because it is responsible for the decrease in mechanical properties, which leads to the general deterioration of rubber from a technical standpoint. It was Marzetti who proved that the decrease of mechanical properties in accelerated aging is due to oxidation. Later, Kohman confirmed this in a more concise way and showed that even such small amounts as 0.5% of oxygen absorbed by vulcanized rubber are sufficient to decrease tensile properties to 50% of their original value. When studying aging, three ways of tackling this problem are possible, viz.: (1) Investigations of the mechanical properties, either under normal conditions, or under special conditions such as elevated temperature or high speed. (2) Determination of oxidation products, which are formed during oxidation of the rubber. (3) Direct determination of the amount of oxygen which is absorbed by the rubber. It is clear that any of these methods may be combined with accelerated aging tests.

scholarly journals To the Construction of the Amplitude Dependence of Internal Friction with Vibrations of Porous Metal Composites

2020 ◽  
Vol 24 (2) ◽  
pp. 37-48
Author(s):  
I. C. Arkhipov ◽  
V. I. Abramova ◽  
A. E. Gvozdev ◽  
E. V. Ageev ◽  
S. N. Kutepov ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Internal Friction ◽  
Potential Energy ◽  
Porous Metal ◽  
Theory Of Elasticity ◽  
High Dispersion ◽  
Amplitude Dependence ◽  
Bending Vibrations ◽  
Metal Composites ◽  
Total Potential

Purpose of research was to plot the amplitude dependence of the decrement of longitudinal and bending vibrations of samples of porous metal composites manufactured using 3D technology.Methods. The main attention is paid to the role of microplasticity in the scattering of the vibration energy, since the decrement value in composite will be greater than in monolithic material. The effect of porosity on the level of energy dissipation is taken into account. We have used a statistical model based on the results of the theory of functionals given on random processes.Results. This made it possible to find the concentration of microplastic zones in the composite during longitudinal and bending vibrations of the sample. The value of the vibration decrement is defined as the ratio of the potential energy of plastic deformations to the total potential energy of the entire sample. To calculate the effective moduli in the composite, the well-known technique of the theory of elasticity of micro-inhomogeneous media is used. The results obtained indicate that porosity significantly affects the concentration of microplastic zones and the scattering of internal friction during longitudinal and bending vibrations. However, it should be noted that at low amplitudes, microplastic regions are not formed in the vicinity of the pores. Therefore, the reasons for the appearance of energy dissipation are not explained only by microplasticity. The source of such losses are dislocation, ferromagnetic and other reasons. However, the level of these losses is much less than that indicated in this work, and depends only on the oscillation frequency.Conclusion. The results obtained can be used to establish the patterns of behavior of various natures of ingot, powder and composite materials with high dispersion in phase and structural components in various conditions and states.

MOLY PERMALLOY

Alloy Digest ◽  
1969 ◽  
Vol 18 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Coercive Force ◽  
Physical Properties ◽  
Tensile Properties ◽  
Core Loss ◽  
Heat Treating ◽  
Hysteresis Loss ◽  
Molybdenum Alloy ◽  
Nickel Iron ◽  
Maximum Permeability

Abstract Allegheny Ludlum Moly Permalloy is a nickel-iron-molybdenum alloy having excellent permeability and core loss properties. It has high initial and maximum permeability, low coercive force, and low hysteresis loss. It is recommended for toroids, tape and lamination cores. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-144. Producer or source: Allegheny Ludlum Steel Corporation.

HIPERNIK

Alloy Digest ◽  
1956 ◽  
Vol 5 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Hysteresis Loss ◽  
Westinghouse Electric Corporation ◽  
Westinghouse Electric ◽  
Maximum Permeability

Abstract HIPERNIK is an alloy of iron and nickel in nearly equal proportions with small amounts of manganese and silicon added. It has exceptionally high initial and maximum permeability and extremely low hysteresis loss. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-26. Producer or source: Westinghouse Electric Corporation.

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