A consistently compressible Mooney‐Rivlin model for the vulcanized rubber based on the Penn's experimental data

Author(s):  
Xiangfeng Peng ◽  
Lei Han ◽  
Luxian Li
1962 ◽  
Vol 35 (2) ◽  
pp. 371-378 ◽  
Author(s):  
G. M. Bartenev

Abstract 1. As a result of analysis of the formulas of friction of rubber and of a comparison with experimental data for steady-state friction on smooth solid surfaces it is demonstrated that the friction of vulcanized rubber is determined by three constants of the material, depending upon the type of rubber polymer and the structure of the vulcanizate. 2. The constant α characterizes the constant of the formation of the area of actual contact Sa under loading. This constant does not depend upon the rate of slip and the nature of the solid surface, but it does depend upon the stiffness of the vulcanizate, which is directly proportional to the crosslink density. 3. The tangential stress on the actual area of contact α=F/Sa depends upon the temperature, the rate of slip and the two constants of the material Sk and U. The first of these is the effective area of contact of a chain with the solid surface, depending upon the number of chains in the network of the vulcanizate, the second is the activation energy, depending upon the nature of the frictioning surfaces, in particular upon the structure of the polymer chain of rubber. 4. A method is proposed for calculating the area of actual contact of a vulcanizate from the number of chains per unit volume and from the number of chains which are in contact with the solid surface.


1963 ◽  
Vol 36 (1) ◽  
pp. 59-63
Author(s):  
G. M. Bartenev ◽  
L. A. Vishnitskaya

Abstract Consideration is made in this article of the uniaxial stress and compression deformation of vulcanized rubber, for which there exists a sufficient amount of accurate experimental data. One of the present authors established a considerable while back that for lattice polymers (vulcanized rubbers) in the coordinates σ (true stress) and ε (deformation) , the equilibrium curves for stress in the range 100 to 200% are expressed by practically straight lines. Furthermore, this behavior was confirmed in a number of our investigations based on more accurate methods of measurement (cf. Reference 2), and also in a number of foreign papers. (Note 1. The stress is regarded in relation to the actual cross-section of the specimen of deformed rubber, the deformation in relation to the initial length of the specimen. Note 2. For comparison of single-parameter formulas with experience the experimental data are presented each time in coordinates such that a straight line corresponded to the formula in these coordinates. For these coordinates we selected the stress σ and the “generalized coordinate” of deformation ε0, which is a different function of the multiple of stress A in the various single-parameter equations.) Within the limits of scatter of the experimental data the equilibrium curves for uniaxial deformation below the limit of proportionality (100–200% with stress and 20–30% for compression) are expressed by the following single-parameter law:


1963 ◽  
Vol 36 (1) ◽  
pp. 1-10 ◽  
Author(s):  
F. Bueche ◽  
T. J. Dudek

Abstract A new molecular theory of tensile strength has been formulated for amorphous gum vulcanizates at temperatures well above the glass temperature and found to be in agreement with recent experimental data. It is shown that the stress on the rubber at break will consist of two parts, the normal kinetic theory stress on the network and the highly rate dependent stress held by the fully extended chains. The fraction of the chains in the fully extended state at the instant of break is greater for a lightly crosslinked rubber than for a highly vulcanized rubber under nonequilibrium test conditions. The theory allows the molecular weight of the freely orienting unit to be calculated. Reasonable values are obtained for EPR and SBR which lend support to the validity of the ideas involved. The kinetic-theory stress contributes the major portion of the stress at break in highly crosslinked amorphous gum rubbers. However, the stress at break for low degrees of crosslinking is largely the result of stresses in the most highly elongated chains.


Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.


Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.


Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.


2018 ◽  
Vol 106 (6) ◽  
pp. 603 ◽  
Author(s):  
Bendaoud Mebarek ◽  
Mourad Keddam

In this paper, we develop a boronizing process simulation model based on fuzzy neural network (FNN) approach for estimating the thickness of the FeB and Fe2B layers. The model represents a synthesis of two artificial intelligence techniques; the fuzzy logic and the neural network. Characteristics of the fuzzy neural network approach for the modelling of boronizing process are presented in this study. In order to validate the results of our calculation model, we have used the learning base of experimental data of the powder-pack boronizing of Fe-15Cr alloy in the temperature range from 800 to 1050 °C and for a treatment time ranging from 0.5 to 12 h. The obtained results show that it is possible to estimate the influence of different process parameters. Comparing the results obtained by the artificial neural network to experimental data, the average error generated from the fuzzy neural network was 3% for the FeB layer and 3.5% for the Fe2B layer. The results obtained from the fuzzy neural network approach are in agreement with the experimental data. Finally, the utilization of fuzzy neural network approach is well adapted for the boronizing kinetics of Fe-15Cr alloy.


1981 ◽  
Vol 20 (04) ◽  
pp. 207-212 ◽  
Author(s):  
J. Hermans ◽  
B. van Zomeren ◽  
J. W. Raatgever ◽  
P. J. Sterk ◽  
J. D. F. Habbema

By means of a case study the choice between several methods of discriminant analysis is presented. Experimental data of a two-groups problem with one or two variables is analysed. The different methods are compared according to posterior probabilities which can be computed for each subject and which are the basis of discriminant analysis. These posterior probabilities are analysed graphically as well as numerically.


2020 ◽  
Vol 39 (4) ◽  
pp. 5905-5914
Author(s):  
Chen Gong

Most of the research on stressors is in the medical field, and there are few analysis of athletes’ stressors, so it can not provide reference for the analysis of athletes’ stressors. Based on this, this study combines machine learning algorithms to analyze the pressure source of athletes’ stadium. In terms of data collection, it is mainly obtained through questionnaire survey and interview form, and it is used as experimental data after passing the test. In order to improve the performance of the algorithm, this paper combines the known K-Means algorithm with the layering algorithm to form a new improved layered K-Means algorithm. At the same time, this paper analyzes the performance of the improved hierarchical K-Means algorithm through experimental comparison and compares the clustering results. In addition, the analysis system corresponding to the algorithm is constructed based on the actual situation, the algorithm is applied to practice, and the user preference model is constructed. Finally, this article helps athletes find stressors and find ways to reduce stressors through personalized recommendations. The research shows that the algorithm of this study is reliable and has certain practical effects and can provide theoretical reference for subsequent related research.


Sign in / Sign up

Export Citation Format

Share Document