Quantitative Characterization of Cure. I. Relationship between Modulus and Strain of Pure-Gum Natural-Rubber Vulcanizates

1952 ◽  
Vol 25 (3) ◽  
pp. 430-439 ◽  
Author(s):  
R. F. Blackwell
Keyword(s):  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Quantitative Characterization ◽  
Strain Data ◽  
Tentative Explanation ◽  
Natural Rubber Vulcanizates ◽  
The Relationship ◽  
Mooney Equation

Abstract The object of this investigation was to determine whether the relationship between strain (elongation) and modulus is sufficiently close for one to be calculated from the other. Stress-strain data have been recorded for loads of 2–10 kg. per sq. cm. for a series of ACS1 and other pure-gum compounds. It is shown that the strain at a fixed stress (5 kg. per sq. cm.) is uniquely related to the load required to produce an elongation of 100 per cent. A tentative explanation of this observation is given in terms of the Mooney equation for the stress-strain curve. It is shown that the second constant of this equation does not vary greatly from rubber to rubber.

A Theoretical and Experimental Analysis of the General Wool Fiber Stress-Strain Behavior with Particular Reference to Structural and Dimensional Nonuniformities

1969 ◽  
Vol 39 (2) ◽  
pp. 121-140 ◽  
Author(s):  
J. D. Collins ◽  
M. Chaikin
Keyword(s):  
Structural Variation ◽  
Strain Curve ◽  
Fiber Material ◽  
Effective Area ◽  
Stress Strain Curve ◽  
Fiber Stress ◽  
Stress Strain ◽  
Strain Behavior ◽  
Area Variation ◽  
The Relationship

The general wool-type three-region behavior (i.e., Hookean, yield, and post-yield regions) is examined both theoretically and experimentally. In order to account for the influence of structural variation, the concept of effective area is introduced and it is shown that this effective area may differ according to the region in which the fiber is being extended. The general effects of effective-area variation on the regions of the stress-strain curve are derived and these are applied to a number of theoretical situations to demonstrate the stress-strain possibilities. It is shown that the relationship between the stress-strain curves for different sets of conditions can be quite complex since the nonuniformity relationships for the various regions of the curves and between curves may vary according to the conditions of testing. Two examples are given of the application of the theory in practice. The behavior of fibers in water and hydrochloric acid are compared and it is shown that there are variations in the effect of the acid within the fiber. The behavior of abraded fibers is examined and it is found that differences previously attributed by other workers to differences between the ortho and para components of the fibers are actually due to variable bond breakdown within the fiber material.

Uniaxial Deformation of Rubber Cylinders

1995 ◽  
Vol 68 (5) ◽  
pp. 739-745 ◽  
Author(s):  
P. H. Mott ◽  
C. M. Roland
Keyword(s):  
Strain Curve ◽  
Uniaxial Deformation ◽  
Deflection Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Optical Birefringence ◽  
Parabolic Profile ◽  
Strain Data ◽  
Tension And Compression ◽  
Actual Stress

Abstract Stress, strain and optical birefringence measurements were made on elastomeric cylinders deformed in tension and compression. The birefringence data enables the actual stress to be determined even when the deformation is not homogeneous. In the absence of lubricant, uniaxially loaded rubber cylinders deviate from homogeneous deformation due to bonding of the cylinder ends. The existing analysis to correct the force-deflection curve for the effect of this sticking, strictly valid for infinitesimal strains, is premised on the idea that the deformed cylinder has a parabolic profile. Experimentally, however, it was found that slender rubber cylinders assume a much flatter profile, while maintaining constant volume, when deformed. Nevertheless, the accuracy of the stress-strain curve when the standard correction is applied turns out to be quite good, partially a result of cancellation of two, relatively small, errors. This accuracy was assessed by comparison of force-deflection data from bonded cylinders both to stress-strain data obtained on lubricated cylinders and to the stresses deduced from the measured birefringence.

Mathematical Modelling of the Stress-Strain Curve for 31VMn12 Ecological Steel

2017 ◽  
Vol 54 (3) ◽  
pp. 409-413
Author(s):  
Carmen Otilia Rusanescu ◽  
Cosmin Jinescu ◽  
Marin Rusanescu ◽  
Maria Cristiana Enescu ◽  
Florina Violeta Anghelina ◽  
...  
Keyword(s):  
Mathematical Modelling ◽  
Strain Curve ◽  
Torsion Test ◽  
Processing Parameters ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
Relationship Of ◽  
The Mathematical Model ◽  
The Relationship

In this paper, optimum hot formation processing parameters for 31VMn12 steel were established, the torsion deformation of 31VMn12 steel was investigated at temperatures from 900, 1000, 11000C and strain rates from 0.05 s-1 to 3 s. -1. There were studied the structural aspects of materials, in microstructures by electronic microscopy. The stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by a Zenner-Hollomon parameter. The mathematical model presented in the paper describes the relationship of tension strain, voltage and temperature coefficient 31VMn12 steel at high temperatures. The stress-strain curves determined by the torsion test allowed the calculation of the Zenner-Hollomon parameter corresponding to the maximum stress. By using this parameter has established a set of equations that reproduce completely stress-strain curve, including the hardening, the restoration and dynamic recrystallization area. Comparisons were made between the experimental results and the predicted and confirmed that constitutive equations developed can be used for mathematical modelling and other attempts (forging, compression) and other types of steel.

A Contribution to the Characterization of the Plastic-Elastic State

1939 ◽  
Vol 12 (4) ◽  
pp. 799-804 ◽  
Author(s):  
E. Rohde
Keyword(s):  
Characteristic Property ◽  
Strain Curve ◽  
The Other ◽  
Elastic State ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Vulcanized Rubber ◽  
Other Hand ◽  
Puzzling Problem

Abstract The manner in which vulcanized rubber can be deformed and yet return almost completely to its original dimensions after the stress is released is a unique and characteristic property. Technically the problem in testing rubber is to evaluate this property and to define it in terms of the factors which are concerned. To define completely this property of rubber whereby it is susceptible to deformation, it is necessary to know the stress, the elongation, the energy expended, the energy lost, the time and the temperature. The stress, elongation and energy expended are closely related and are characterized by the stress-strain curve, which in turn depends on the time and temperature. In addition, it must be borne in mind that rubber can be deformed either by tension or by pressure, but this will not be discussed further here. On the other hand a rather puzzling problem will be considered, the solution of which brings out the fact that the three variables involved in any deformation, viz.: (1) The time or frequency. (2) The temperature. (3) The interrelated factors: stress, elongation and energy expended, must be varied considerably in order to characterize the phenomena of deformation and that when this is done, unexpected results are obtained.

Effect of Gamma-Irradiation towards Stress-Strain Curve of Single Die QFN Package

2011 ◽  
Vol 694 ◽  
pp. 620-624 ◽  
Author(s):  
Wan Yusmawati Wan Yusoff ◽  
Azman Jalar ◽  
Norinsan Kamil Othman ◽  
Irman Abdul Rahman
Keyword(s):  
Gamma Irradiation ◽  
Strain Curve ◽  
Stress And Strain ◽  
Flexural Stress ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Three Point Bending ◽  
Strain Behaviour ◽  
The Relationship ◽  
Different Doses

The aim of the research was to establish the relationship between stress-strain behaviour of single die Quad Flat No lead (SDQFN) and degradation by gamma irradiation. The SDQFN was exposed to Cobalt-60 with different doses from 0.5 Gy, 1.5 Gy, 5.0 Gy, 10.0 Gy and 50.0 kGy. The three-point bending technique was used to measure the flexural stress and strain of the package behaviour relations. After exposing with gamma radiation, the result showed the decreasing in the strength of the package behaviour of irradiated SDQFN when increasing the dose of gamma irradiation. The highest gamma irradiation dose used in this work produced the highest change in stress-strain behaviour of irradiated SDQFN.

Tensile stress/strain characterization of non-linear materials

1981 ◽  
Vol 16 (2) ◽  
pp. 107-110 ◽  
Author(s):  
J Margetson
Keyword(s):  
Strain Curve ◽  
Uniaxial Stress ◽  
Aerodynamic Heating ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Strain Characterization ◽  
Least Squares Fit ◽  
Experimental Values ◽  
Good Agreement

A uniaxial stress/strain curve is represented empirically by a modified Ramberg-Osgood equation ∊=(σ/E) + (σ/σo)m. Firstly E is extracted then σo and m are determined from two points on the experimental curve. These values are improved iteratively by a least squares fit using all the experimental points on the curve. The procedure is used to generate stress/strain relationships for a variety of materials and there is good agreement with the experimental values. The method is also applied to a simulated aerodynamic heating experiment.

Quantitative Characterization of Cure. III. Relation between Compound Viscosity and Vulcanizate Stiffness in Pure-Gum Natural-Rubber Vulcanizates

1952 ◽  
Vol 25 (3) ◽  
pp. 446-454 ◽  
Author(s):  
R. F. Blackwell ◽  
W. P. Fletcher ◽  
Geoffrey Gee
Keyword(s):  
Natural Rubber ◽  
Considerable Reduction ◽  
Test Compound ◽  
Quantitative Characterization ◽  
Mooney Viscosity ◽  
Natural Rubber Vulcanizates ◽  
The Relationship

Abstract The aim of this investigation was to study the dependence of vulcanizate stiffness on the compound Mooney viscosity, and if possible to derive a method by which account could be taken of variations in viscosity in order to reduce the so-called mixing error in batches of test compound. Investigations covering a range of compounds, raw rubbers, and curing times gave results which for the practical range indicated a relation between modulus at 100 per cent elongation and Mooney viscosity. Using the relationship thus established, a method of adjusting modulus results to correspond to a standard Mooney viscosity was derived. Application of the scheme to batches of ACS1 compound mixed from parts of the same lot of homogeneous raw rubber led to a considerable reduction in the range of modulus values.

scholarly journals Nonlinear Simulation of Stress-Strain Curve of Infill Materials Using PLP Fit Model

1970 ◽  
Vol 7 (1) ◽  
pp. 99-110
Author(s):  
Prajwal Lal Pradhan ◽  
C.V. R. Murty ◽  
Karl Vincent Hoiseth ◽  
Mohan Prasad Aryal
Keyword(s):  
Experimental Investigation ◽  
Modulus Of Elasticity ◽  
Stress Function ◽  
Strain Curve ◽  
Yield Limit ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Nonlinear Simulation ◽  
Strain Relationship ◽  
The Relationship

This paper puts forward an idealization of stress-strain curve of structural materials like bricks, and mortar. In this model, below yield limit, the pattern of the stress-strain relationship is assumed to be linear i.e. modulus of elasticity remains unchanged, whereas beyond the limit, the relationship is supposed to be curvilinear. A quadratic stress function is assumed to formulate the stress-strain curve passing through the points of yield stress sy and ultimate stress su. Experimental investigation on the cube-tests of specimen for brick samples and mortar cubes are also presented for the verification of idealized stress-strain relationships.Journal of the Institute of Engineering, Vol. 7, No. 1, July, 2009 pp. 99-110doi: 10.3126/jie.v7i1.2067

The Bursting Pressure of Cylindrical and Spherical Vessels

1958 ◽  
Vol 25 (1) ◽  
pp. 89-96
Author(s):  
N. L. Svensson
Keyword(s):  
Internal Pressure ◽  
Excellent Agreement ◽  
Strain Curve ◽  
Experimental Results ◽  
Bursting Pressure ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
The Relationship

Abstract The relationship between pressure and change of dimensions for cylindrical and spherical vessels subjected to internal pressure is considered for a material having a stress-strain curve of the form σ = σ0ϵn. The equations obtained are analyzed further to obtain expressions for the bursting pressure for these vessels. From these results simplified expressions are obtained for the calculation of the bursting pressure for any vessel. Comparison with one set of experimental results shows excellent agreement.

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