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Showing 1 to 20 of 97 for “"Poisson's ratio"”.
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Dynamic measurement and characterization of Poisson's ratio
Poisson's ratio for aluminum is estimated from velocity profile measurements of a free-free beam under dynamic loading conditions A weighted least-squares method is used to select a beam model which is subsequently used to determine the transverse and anticlastic radii of curvature. The model of …
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Investigation of Elastic Parameters and Pavement Modeling With Eps Geofoam
… tests on small size samples. Young's modulus and Poisson's ratio are parameters required to model isotropic and homogenous material behavior. For the most widely used EPS density grade of 20 Kg/m3 (1.25 pcf), Young's modulus of 4 MPa and Poisson's ratio of 0.1 are commonly used. Use of these …
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Elasticity Measurement at High Temperatures
… is used to excite the resonant modes of vibration of thin discs. The temperature variations of Poisson's Ratio and Young's modulus are measured using these modes. The elastic constants of a variety of grades of graphite, including pyrolytic graphite (which was found to have a negative …
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Crack growth, singularities and wave propagation in auxetic composite materials
… material is a material which has a negative Poisson's ratio, so they exhibit lateral expansion upon longitudinal tensile loading, or undergo lateral contraction under longitudinal compression. Such materials can exist in cellular form, or along specific axes in certain crystals. The …
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A new class of auxetic lattices
… three different realizations that leads to a Poisson's ratio arbitrarily close to the thermodynamic limit corresponding to ν = -1. The effect is achieved by the superposition of clockwise and anti-clockwise internal rotations leading to a macroscopic non-chiral effect. We have detailed the …
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Finite element analysis of damaged cross-ply composite laminates
… analysis. The degradation of elastic modulus, Poisson's ratio, shear modulus, and coefficient of thermal expansion was predicted and then compared with analytical models and experimental data. The elastic modulus was predicted to exhibit relatively small degradation as a function of crack …
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Analysis of Composite Laminates with Matrix Cracks
… laminate properties, such as axial stiffness, Poisson's ratio, shear modulus, and coefficient of thermal expansion, as a function of crack density and the axial stress redistribution due to the existence of matrix cracks. Both transverse cracks (2-D problem) and cross (transverse and …
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Wave propagation in finite element and mass-spring-dashpot lattice models
… in the ultrasonic phase speed with variations in Poisson's ratio and angle of incidence is evaluated in each model of an isotropic elastic solid. With regard to phase speed, materials with constant N grid spaces per P-wavelength having Poisson's ratios between 0.0 and 0.25 are modeled more …
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Wave propagation in finite element and mass-spring-dashpot lattice models
… in the ultrasonic phase speed with variations in Poisson's ratio and angle of incidence is evaluated in each model of an isotropic elastic solid. With regard to phase speed, materials with constant N grid spaces per P-wavelength having Poisson's ratios between 0.0 and 0.25 are modeled more …
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Experimental and finite element analysis of mechano-electrochemical effects in intervertebral disc biomechanics
… mechanical properties such as permeability and Poisson's ratio is still not fully understood. Therefore, this thesis aimed to investigate the influence of such phenomena on disc mechanics whilst providing a comparison between multiphasic FE models and experimental data. Direct permeation …
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Evaluation of Site Response Analysis for Vertical Ground Motions in LS-DYNA Using Geotechnical Downhole
… to horizontal (noise or earthquake) spectral ratios to convert ground motion prediction equation outputs to the vertical direction. The final goal of this study was to validate the methods used in order to justify the extension of the method to conduct soil structure interaction under vertical …
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Characterisation of micromechanical materials and MEMS structures using optically generated ultrasound
… of excitation wavelength, influence the generation of Lamb waves. As a result, it was concluded that light of wavelength 532 nm is the optimal wavelength for Lamb wave generation. The capabilities of laser-generated Lamb waves, coupled with a large bandwidth Michelson interferometer, have …
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The vibrational spectra of rectangular plates
… used to excite and measure modes of vibration of thin rectangular plates. The frequency spectra of different modes have been investigated as a function of the material elastic moduli and the plate geometry. Most of the work was carried out on isotropic materials. For square plates a wide …
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General nonlinear plate theory applied to a circular plate with large deflections
… form solution is obtained for this problem when Poisson's ratio is equal to 1/3. An approximate solution is obtained for any value of Poisson's ratio for the case where the deflections are very large. The second problem is the same as the first with the addition of a small torque about a normal …
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Elastic constants from molecular mechanics simulations of frequencies of free-free single-walled carbon nanotubes and clamped single-layer graphene sheets
… (SLGSs) are determined by studying their free vibration characteristics using molecular mechanics (MM) simulations with the MM3 potential and finding their equivalent continuum structures (ECSs). The computational framework has been validated by comparing the presently computed basal plane …
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Elastic Waves Along a Fracture Intersection
… motion and velocity of intersection waves. Vibrational modes calculated from the theoretical formulation match those predicted by group theory based on the symmetry of the problem.</p> <p>For the coupled wedge wave, two vibrational modes exist that range in velocity between the wedge wave and …
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Techniques for evaluating the behavior of apple skin under tensile loading
… secant modulus, tensile strength at break, and Poisson's ratio. The effect of displacement rate and specimen orientation on the strength was investigated. The apple skin was found to be anisotropic, with the maximum strength in a direction parallel to the core. It was observed that Poisson's …
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Measuring particle alignment in particleboard and predicting selected mechanical properties of oriented boards
… however, was only effective for thin plates. Poisson's ratio, the tensile modulus, modulus of elasticity, and modulus of rupture increased in the direction of particle alignment as the degree of orientation increased. The shear modulus decreased as the orientation increased. The results …
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Nonlinear free vibration of beams by one-dimensional and elasticity solutions
In this research, linear and nonlinear free vibration are examined. A three-dimensional rectangular parallelepiped free–free beam is studied based on the Ritz method. The equation of motion is derived depending on Hamilton's principle. A validation of the Ritz method formulation has been conducted …
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X-ray Scattering Study Of Capillary Condensation In Mesoporous Silica
… analysis of various forces acting on it. The Poisson's ratio and elastic moduli of the two samples and their annealed forms were estimated and compared quantitatively. Our study demonstrates a novel WAXS-based technique for calculating the mechanical properties of nanoporous materials with …
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