Frequency‐dependent elastic properties of rubberlike materials with a random distribution of voids

1984 ◽  
Vol 76 (1) ◽  
pp. 296-300 ◽  
Author(s):  
V. K. Varadan ◽  
V. V. Varadan ◽  
Y. Ma
Keyword(s):  
Elastic Properties ◽  
Random Distribution ◽  
Frequency Dependent ◽  
Rubberlike Materials

Hysteretic and Elastic Properties of Rubberlike Materials Under Dynamic Shear Stresses

1944 ◽  
Vol 15 (4) ◽  
pp. 309-323 ◽  
Author(s):  
J. H. Dillon ◽  
I. B. Prettyman ◽  
G. L. Hall
Keyword(s):  
Elastic Properties ◽  
Shear Stresses ◽  
Dynamic Shear ◽  
Rubberlike Materials

Adiabatic Stretching as a Method of Investigation of the Elastic Properties of Rubberlike Materials

1956 ◽  
Vol 29 (4) ◽  
pp. 1209-1214
Author(s):  
M. P. Votinov ◽  
E. V. Kuvshinskiĭ
Keyword(s):  
Elastic Properties ◽  
Direct Method ◽  
Rubber Compounds ◽  
A Direct Method ◽  
Rubberlike Materials ◽  
Elastic Characteristics

Abstract 1. A direct method has been proposed for the study of the elastic characteristics of rubber stocks under nonequilibrium deformation conditions. 2. This method has been successfully applied in the study of the elastic characteristics of “crystallizing” and “noncrystallizing” unloaded rubber compounds.

Experimental study on frequency‐dependent elastic properties of weakly consolidated marine sandstone: effects of partial saturation

2020 ◽  
Vol 68 (9) ◽  
pp. 2808-2824
Author(s):  
Hui Li ◽  
Luanxiao Zhao ◽  
De‐hua Han ◽  
Jinghuai Gao ◽  
Hemin Yuan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Elastic Properties ◽  
Partial Saturation ◽  
Frequency Dependent

Estimating elastic properties and attenuation factor from different frequency components of observed seismic data

2019 ◽  
Vol 220 (2) ◽  
pp. 794-805
Author(s):  
Huaizhen Chen
Keyword(s):  
Reflection Coefficient ◽  
Elastic Properties ◽  
Seismic Data ◽  
Wave Attenuation ◽  
Attenuation Factor ◽  
P Wave ◽  
S Wave ◽  
Data Set ◽  
Frequency Dependent ◽  
Frequency Components

SUMMARY Based on an attenuation model, we first express frequency-dependent P- and S-wave attenuation factors as a function of P-wave maximum attenuation factor, and then we re-express P- and S-wave velocities in anelastic media and derive frequency-dependent stiffness parameters in terms of P-wave maximum attenuation factor. Using the derived stiffness parameters, we propose frequency-dependent reflection coefficient in terms of P- and S-wave moduli at critical frequency and P-wave maximum attenuation factor for the case of an interface separating two attenuating media. Based on the derived reflection coefficient, we establish an approach to utilize different frequency components of observed seismic data to estimate elastic properties (P- and S-wave moduli and density) and attenuation factor, and following a Bayesian framework, we construct the objective function and an iterative method is employed to solve the inversion problem. Tests on synthetic data confirm that the proposed approach makes a stable and robust estimation of unknown parameters in the case of seismic data containing a moderate noise/error. Applying the proposed approach to a real data set illustrates that a reliable attenuation factor is obtained from observed seismic data, and the ability of distinguishing oil-bearing reservoirs is improved combining the estimated elastic properties and P-wave attenuation factor.

scholarly journals Search for supersolidity in solid 4He using multiple-mode torsional oscillators

2016 ◽  
Vol 113 (23) ◽  
pp. E3203-E3212 ◽  
Author(s):  
Anna Eyal ◽  
Xiao Mi ◽  
Artem V. Talanov ◽  
John D. Reppy
Keyword(s):  
Elastic Properties ◽  
Condensed Matter ◽  
Solid 4He ◽  
Multiple Frequency ◽  
Small Frequency ◽  
Frequency Dependent ◽  
Total Period ◽  
Period Shift ◽  
Frequency Independent ◽  
Supersolid State

In 2004, Kim and Chan (KC) reported a decrease in the period of torsional oscillators (TO) containing samples of solid 4He, as the temperature was lowered below 0.2 K [Kim E, Chan MHW (2004) Science 305(5692):1941–1944]. These unexpected results constituted the first experimental evidence that the long-predicted supersolid state of solid 4He may exist in nature. The KC results were quickly confirmed in a number of other laboratories and created great excitement in the low-temperature condensed-matter community. Since that time, however, it has become clear that the period shifts seen in the early experiments can in large part be explained by an increase in the shear modulus of the 4He solid identified by Day and Beamish [Day J, Beamish J (2007) Nature 450(7171):853–856]. Using multiple-frequency torsional oscillators, we can separate frequency-dependent period shifts arising from changes in the elastic properties of the solid 4He from possible supersolid signals, which are expected to be independent of frequency. We find in our measurements that as the temperature is lowered below 0.2 K, a clear frequency-dependent contribution to the period shift arising from changes in the 4He elastic properties is always present. For all of the cells reported in this paper, however, there is always an additional small frequency-independent contribution to the total period shift, such as would be expected in the case of a transition to a supersolid state.

Hysteretic and Elastic Properties of Rubberlike Materials under Dynamic Shear Stresses

1944 ◽  
Vol 17 (3) ◽  
pp. 597-616 ◽  
Author(s):  
J. H. Dillon ◽  
I. B. Prettyman ◽  
G. L. Hall
Keyword(s):  
Natural Rubber ◽  
Elastic Properties ◽  
Shear Stresses ◽  
Dynamic Shear ◽  
Small Problem ◽  
Principal Problem ◽  
Synthetic Rubber ◽  
Truck Tire ◽  
Hysteretic Properties ◽  
Rubberlike Materials

Abstract The principal problem of the rubber technologist and engineer today is that of applying the various types of synthetic rubber to products which undergo rapid repeated flexure. All commercially available synthetic rubbers possess a greater hysteresis defect than does natural rubber. Hence, the task of designing a product such as a large truck tire, where heat development has been no small problem even with natural rubber, is much more difficult. Consequently, the accompanying problem of evaluating the hysteretic properties of rubberlike materials has assumed new importance.

Structure of Rubber

1939 ◽  
Vol 12 (2) ◽  
pp. 119-123
Author(s):  
C. J. B. Clews
Keyword(s):  
Solid State ◽  
Recent Work ◽  
Elastic Properties ◽  
Random Distribution ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Accurate Data ◽  
X Ray

Abstract The results of the x-ray study of rubber structure may be summarized as follow : (1) The unit cell is monoclinic, space group C2h5, a=8.53±0.05, b=8.16±0.05, c=12.66±0.05 A˚, β=83°20′, with four isoprene chains in the cis modification passing through the cell, which contains 8 C5H8 residues. (2) In the unstretched state there is a random distribution of ordered crystalline regions and disordered regions. On stretching, the crystalline regions become orientated in one or more crystallographic directions, thereby giving rise to the x-ray fibre diagram. The crystalline regions may be identified with the micelles, which are groups of Hauptvalenzketten bound together by van der Waals' forces; a given Hauptvalenzkette is undoubtedly associated with more than one micelle. It is possible that the abnormal elastic properties are due to the chains becoming aligned parallel to the direction of stretching, and in addition there may be some extension of the chains themselves. Such an effect has been observed by Astbury in his work on keratin. Some recent work on the structure of butadiene and its derivatives in the solid state is described, which, although offering no immediate solution of our problem, may prove of value when further accurate data are available, both for these compounds and for the corresponding rubbers.

Sign in / Sign up

Export Citation Format

Share Document