scholarly journals DYNAMIC AND STATIC VISCO-ELASTIC CONSTANTS AND POISSON'S RATIO OF CLAY, SAND AND CRUSHED STONE

1969 ◽  
Vol 1969 (164) ◽  
pp. 33-49
Author(s):  
Tadashi Hatano ◽  
Hiroyuki Watanabe
Keyword(s):  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Crushed Stone

scholarly journals Direct Determination of Dynamic Elastic Modulus and Poisson’s Ratio of Timoshenko Rods

Vibration ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 157-173 ◽  
Author(s):  
Guadalupe Leon ◽  
Hung-Liang Chen
Keyword(s):  
Exact Solution ◽  
Finite Element ◽  
Elastic Constants ◽  
Frequency Ratio ◽  
Poisson’S Ratio ◽  
Direct Determination ◽  
Poisson's Ratio ◽  
Torsional Mode ◽  
Bending Mode ◽  
Resonance Frequencies

In this paper, the exact solution of the Timoshenko circular beam vibration frequency equation under free-free boundary conditions was determined with an accurate shear shape factor. The exact solution was compared with a 3-D finite element calculation using the ABAQUS program, and the difference between the exact solution and the 3-D finite element method (FEM) was within 0.15% for both the transverse and torsional modes. Furthermore, relationships between the resonance frequencies and Poisson’s ratio were proposed that can directly determine the elastic constants. The frequency ratio between the 1st bending mode and the 1st torsional mode, or the frequency ratio between the 1st bending mode and the 2nd bending mode for any rod with a length-to-diameter ratio, L/D ≥ 2 can be directly estimated. The proposed equations were used to verify the elastic constants of a steel rod with less than 0.36% error percentage. The transverse and torsional frequencies of concrete, aluminum, and steel rods were tested. Results show that using the equations proposed in this study, the Young’s modulus and Poisson’s ratio of a rod can be determined from the measured frequency ratio quickly and efficiently.

Role of Elastic Constants in Certain Contact Problems

1970 ◽  
Vol 37 (4) ◽  
pp. 965-970 ◽  
Author(s):  
J. Dundurs ◽  
M. Stippes
Keyword(s):  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Contact Problems ◽  
Poisson's Ratio ◽  
Two Dimensional ◽  
Frictionless Contact ◽  
Plane Contact

The dependence of stresses on the elastic constants is explored in frictionless contact problems principally for the case when the contacting bodies are made of the same material and the deformations are induced by prescribed surface tractions. The strongest results can be obtained for problems with contacts that either recede or remain stationary upon loading. In such problems, the stresses are proportional to the applied tractions and the extent of contact is independent of the level of loading. Furthermore, it is shown that the Michell result regarding the dependence of stresses on Poisson’s ratio carries over to plane contact problems with receding and stationary contacts. In three and two-dimensional problems with advancing contacts, it is possible to establish certain rules for scaling displacements and stresses.

scholarly journals On the identification of the eggshell elastic properties under quasistatic compression

2004 ◽  
Vol 52 (5) ◽  
pp. 73-82 ◽  
Author(s):  
Jana Simeonovová ◽  
Jaroslav Buchar
Keyword(s):  
Young’S Modulus ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Rotational Shell ◽  
Mutual Comparison ◽  
Quasistatic Loading

The problem of the identification of the elastic properties of eggshell, i.e. the evaluation of the Young's modulus and Poisson's ratio is solved. The eggshell is considered as a rotational shell. The experiments on the egg compression under quasistatic loading have been conducted. During these experiments a strain on the eggshell surface has been recorded. By the mutual comparison between experimental and theoretical values of strains the influence of the elastic constants has been demonstrated.

scholarly journals A systematic typology for negative Poisson's ratio materials and the prediction of complete auxeticity in pure silica zeolite JST

2015 ◽  
Vol 17 (27) ◽  
pp. 17927-17933 ◽  
Author(s):  
M. Siddorn ◽  
F.-X. Coudert ◽  
K. E. Evans ◽  
A. Marmier
Keyword(s):  
Single Crystals ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Negative Poisson’S Ratio ◽  
Zeolite Framework ◽  
Pure Silica ◽  
Negative Poisson's Ratio

From experimental elastic constants, partial auxeticity occurs in around 37% of single crystals, average auxeticity is limited to α-cristobalite and complete auxeticity is not observed. Two hundreds pure silica zeolites are simulated and complete auxeticity is found in the JST zeolite framework.

Effect of changes in elastic constants on the strength of composites

1988 ◽  
Vol 23 (4) ◽  
pp. 213-221 ◽  
Author(s):  
W Zhang ◽  
K E Evans
Keyword(s):  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Maximum Stress ◽  
High Strength ◽  
Poisson's Ratio ◽  
Failure Strength ◽  
Failure Envelope ◽  
Strength Parameters ◽  
Failure Envelopes ◽  
Strain Space

Tensor polynomial, maximum stress, and maximum strain criteria are considered in an investigation of the effect of varying elastic constants on the failure strength of composites. By expressing each criterion in the alternative stress or strain space they are made explicitly dependent on elastic constants as well as strength parameters. The significance of this result is highlighted by an example of the variation in failure envelope produced by altering the Poisson's ratio of the composite material. In particular the failure envelopes for a high strength graphite/epoxy resin (SP-286/T300) composite lamina are examined as a function of variations in the material's Poisson's ratio. The limits in the variation of the Poisson's ratio for this composite lamina are identified.

scholarly journals The equivalent modulus of elasticity of soil mediums for designing shallow foundations

2021 ◽  
Author(s):  
Lysandros Pantelidis
Keyword(s):  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Theory Of Elasticity ◽  
Shallow Foundations ◽  
Poisson's Ratio ◽  
Deformation Pattern ◽  
Lateral Expansion ◽  
Principle Of Superposition ◽  
Soil Medium ◽  
Equivalent Modulus

Abstract As known, in a Winkler type of analysis the soil medium underneath the foundation is violently replaced by a row of parallel springs having constant ks. For the effective calculation of the latter, which is called the modulus of subgrade reaction, the two elastic constants of the soil (the elastic modulus, E and the Poisson’s ratio, ν) must be known. Although for homogenous soils this generally seems not to be a problem, the same does not stand for stratified mediums or mediums with linearly increasing modulus with depth. In such an analysis, the proper pair of elastic constant values of soil should be selected. This refers to a Poisson’s ratio value equal to zero corresponding to the deformation pattern of springs (compression with no lateral expansion) and the respective modulus. In the present paper a method for calculating the equivalent elastic constants for the above mentioned mediums is proposed based on the theory of elasticity combining the principle of superposition. Various cases are considered, since the equivalent modulus, Eeq, depends on the rigidity and the shape of the footing. As shown, the derived Eeq values not only return reliable settlement results, but also settlement profiles that are similar to those corresponding to the original soil mediums.

Prediction of Elastic Constants of Carbon Fabric/Polyurethane Composites

2016 ◽  
Vol 258 ◽  
pp. 233-236 ◽  
Author(s):  
Shun Fa Hwang ◽  
Hsuan Ting Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Element Model ◽  
Curing Temperature ◽  
Poisson's Ratio ◽  
Fiber Fabric

The purpose of this work is to study a new composite material consisting of polyurethane (PU) resin and carbon fiber fabric. This PU resin is superior in impact, viscosity, low curing temperature, and short curing time. If this resin is combined with fiber fabric by vacuum assisted resin transfer method, the fabrication time will be short. Since it is a braided composite, it’s important to have a model to predict the elastic constants for different braid angels. To predict the elastic constants including Young’s modulus, shear modulus, and Poisson’s ratio, a finite element model is established. In this model a braided layer is treated as two uni-directional layers. Then, the elastic constants of this composite with different braid angels are estimated. After that, the composites with different braid angels are fabricated and tested to obtain the elastic constants, and the comparison with the finite element results is made. The results indicate that the agreement is very good for the Young’s modulus. For the Poisson’s ratio, the difference between the prediction and the measurement is reasonable. From the comparison, it can be concluded that the finite element model is good. Then, this model is used to predict all in-plane elastic constants for arbitrary braid angles.

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