scholarly journals Poisson's ratio of some structural alloys for large strains

1946 ◽  
Vol 37 (4) ◽  
pp. 211 ◽  
Author(s):  
A.H. Stang ◽  
M. Greenspan ◽  
S.B. Newman
Keyword(s):  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Large Strains

Design of an Isotropic Metamaterial With Constant Stiffness and Zero Poisson's Ratio Over Large Deformations

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
A. Delissen ◽  
G. Radaelli ◽  
L. A. Shaw ◽  
J. B. Hopkins ◽  
J. L. Herder
Keyword(s):  
Young’S Modulus ◽  
Material Properties ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Sufficient Conditions ◽  
Material Design ◽  
Poisson's Ratio ◽  
Nonlinear Material ◽  
Large Strains ◽  
Planar Lattice

A great deal of engineering effort is focused on changing mechanical material properties by creating microstructural architectures instead of modifying chemical composition. This results in meta-materials, which can exhibit properties not found in natural materials and can be tuned to the needs of the user. To change Poisson's ratio and Young's modulus, many current designs exploit mechanisms and hinges to obtain the desired behavior. However, this can lead to nonlinear material properties and anisotropy, especially for large strains. In this work, we propose a new material design that makes use of curved leaf springs in a planar lattice. First, analytical ideal springs are employed to establish sufficient conditions for linear elasticity, isotropy, and a zero Poisson's ratio. Additionally, Young's modulus is directly related to the spring stiffness. Second, a design method from the literature is employed to obtain a spring, closely matching the desired properties. Next, numerical simulations of larger lattices show that the expectations hold, and a feasible material design is presented with an in-plane Young's modulus error of only 2% and Poisson's ratio of 2.78×10−3. These properties are isotropic and linear up to compressive and tensile strains of 0.12. The manufacturability and validity of the numerical model is shown by a prototype.

The Use of a Mechano-Lattice Analogy for Determining the Abrading Stresses in Sliding Rubber

1971 ◽  
Vol 44 (3) ◽  
pp. 758-770
Author(s):  
W. O. Yandell
Keyword(s):  
Principal Stress ◽  
Poisson’S Ratio ◽  
Sliding Friction ◽  
Poisson's Ratio ◽  
Large Strains ◽  
Damping Factor ◽  
Stress Strain ◽  
Minor Principal Stress

Abstract A rigorous mechano-lattice analogy analysis for calculating the hysteretic sliding friction of and stresses in rubber sliding on variously shaped asperities is presented. The analysis allows large strains and any Poisson's Ratio, rigidity or damping factor of the rubber. The analysis was used to calculate the distributions of minor principal stress in rubber sliding over smooth and frictional prisms with different sharpnesses and over a cylinder. The potentially disruptive stress regions were thus revealed and compared. The effect of changes in the Poisson's Ratio and of the damping factor of the rubber were also examined. It was postulated that the fine texture generates more stress-strain hysteretic heat which may lead to the more rapid abrasion observed by some workers.

scholarly journals Characterisation and Modelling of a Melt-Extruded LDPE Closed Cell Foam

2011 ◽  
Vol 70 ◽  
pp. 105-110 ◽  
Author(s):  
Qusai Hatem Jebur ◽  
Philip Harrrison ◽  
Zao Yang Guo ◽  
Gerlind Schubert ◽  
Vincent Navez
Keyword(s):  
Uniaxial Compression ◽  
Poisson’S Ratio ◽  
Mechanical Response ◽  
Large Strain ◽  
Transversely Isotropic ◽  
Poisson's Ratio ◽  
Large Strains ◽  
Elastic Model ◽  
Polymer Foam ◽  
Closed Cell

This paper describes uniaxial compression tests on a melt-extruded closed-cell Low-Density Polyethylene (LDPE) foam. The stress-strain response shows the mechanical behaviour of the foam is predominantly transversely isotropic viscoelastic and compressible. Images analysis is used to estimate the Poisson’s ratio under large strains. When the deformation is less than 5 percent, the kinematics and mechanical response of the polymer foam can be well-described by a linear compressible transversely isotropic elastic model. For large strain, a method of manipulating experimental data obtained from testing in the principal and transverse directions (stress vs strain and Poisson’s ratio) in order to estimate the uniaxial compression response of the foam at any arbitrary orientation is proposed. An isotropic compressible hyperfoam model is then used to implement this behaviour in a finite element code.

The Model for Calculating Elastic Modulus and Poisson's Ratio of Coal Body

2013 ◽  
Vol 6 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Ai Chi ◽  
Li Yuwei
Keyword(s):  
Elastic Modulus ◽  
Poisson’S Ratio ◽  
Fractured Rock ◽  
Rock Block ◽  
Poisson's Ratio ◽  
Linear Elastic ◽  
Study Results ◽  
The Face ◽  
Block Face ◽  
Coal Rock

Coal body is a type of fractured rock mass in which lots of cleat fractures developed. Its mechanical properties vary with the parametric variation of coal rock block, face cleat and butt cleat. Based on the linear elastic theory and displacement equivalent principle and simplifying the face cleat and butt cleat as multi-bank penetrating and intermittent cracks, the model was established to calculate the elastic modulus and Poisson's ratio of coal body combined with cleat. By analyzing the model, it also obtained the influence of the parameter variation of coal rock block, face cleat and butt cleat on the elastic modulus and Poisson's ratio of the coal body. Study results showed that the connectivity rate of butt cleat and the distance between face cleats had a weak influence on elastic modulus of coal body. When the inclination of face cleat was 90°, the elastic modulus of coal body reached the maximal value and it equaled to the elastic modulus of coal rock block. When the inclination of face cleat was 0°, the elastic modulus of coal body was exclusively dependent on the elastic modulus of coal rock block, the normal stiffness of face cleat and the distance between them. When the distance between butt cleats or the connectivity rate of butt cleat was fixed, the Poisson's ratio of the coal body initially increased and then decreased with increasing of the face cleat inclination.

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