scholarly journals Analysis of Dynamic Behavior of the Finite Elastic Metamaterial-Based Structure With Frequency-Dependent Properties

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
X. H. Shen ◽  
C. T. Sun ◽  
M. V. Barnhart ◽  
G. L. Huang
Keyword(s):  
Young’S Modulus ◽  
Dynamic Behavior ◽  
Wave Amplitude ◽  
Young's Modulus ◽  
Mass Density ◽  
Effective Density ◽  
Frequency Dependent ◽  
Practical Applications ◽  
Global Dynamic ◽  
Elastic Metamaterials

For practical applications of the elastic metamaterials, dynamic behavior of finite structures made of elastic metamaterials with frequency dependent properties are analyzed theoretically and numerically. First, based on a frequency-dependent mass density and Young's modulus of the effective continuum, the global dynamic response of a finite rod made of elastic metamaterials is studied. It is found that due to the variation of the effective density and Young's modulus, the natural frequency distribution of the finite structure is altered. Furthermore, based on the spectral approach, the general wave amplitude transfer function is derived before the final transmitted wave amplitude for the finite-layered metamaterial structure with decreasing density is obtained using the mathematical induction method. The analytical analysis and finite element solutions indicate that the increased transmission wave displacement amplitude and reduced stress amplitude can be controlled by the impedance mismatch of the adjacent layers of the layered structure.

In-Plane Free Vibration of Uniform Circular Arches Made of Axially Functionally Graded Materials

2019 ◽  
Vol 19 (08) ◽  
pp. 1950084 ◽  
Author(s):  
Joon Kyu Lee ◽  
Byoung Koo Lee
Keyword(s):  
Free Vibration ◽  
Young’S Modulus ◽  
Natural Frequencies ◽  
Dynamic Equilibrium ◽  
Young's Modulus ◽  
Mass Density ◽  
Functionally Graded ◽  
Mode Shapes ◽  
Governing Equations ◽  
Direct Integral

This study focused on the in-plane free vibration of uniform circular arches made of axially functionally graded (AFG) materials. Based on the dynamic equilibrium of an arch element, the governing equations for the free vibration of an AFG arch are derived in this study, where arbitrary functions for the Young’s modulus and mass density are acceptable. For the purpose of numerical analysis, quadratic polynomials for the Young’s modulus and mass density are considered. To calculate the natural frequencies and corresponding mode shapes, the governing equations are solved using the direct integral method enhanced by the trial eigenvalue method. For verification purposes, the predicted frequencies are compared to those obtained by the general purpose software ADINA. A parametric study of the end constraint, rotatory inertia, modular ratio, radius parameter, and subtended angle for the natural frequencies is conducted and the corresponding mode shapes are reported.

Frequency-dependent attenuation in water-saturated cracked glass based on creep tests

Geophysics ◽  
2017 ◽  
Vol 82 (3) ◽  
pp. MR89-MR96 ◽  
Author(s):  
Céline Mallet ◽  
Beatriz Quintal ◽  
Eva Caspari ◽  
Klaus Holliger
Keyword(s):  
Young’S Modulus ◽  
Glass Sample ◽  
Young's Modulus ◽  
Axial Stress ◽  
Creep Tests ◽  
Crack Network ◽  
Frequency Dependent ◽  
Essential Information ◽  
Poroelastic Model ◽  
Water Saturated

We estimate attenuation at subseismic frequencies from an experimental creep test performed on a thermally cracked water-saturated glass sample. The time-dependent axial stress and strain rates are used to infer the attenuation and Young’s modulus as functions of frequency. Attenuation is characterized by a pronounced frequency dependence between [Formula: see text] and [Formula: see text]. A corresponding frequency-dependent behavior of the Young’s modulus is observed with an increase from 60 to 70 GPa, which is consistent with the measured static and ultrasonic values. These observations are interpreted as being due to fluid flow between interconnected cracks in the mesoscopic scale range. To test this hypothesis, we compare the analytical characteristic frequency for the presumed mesoscopic squirt-type flow with its experimental counterpart. We also compare the experimentally observed attenuation characteristics with results of numerical simulations. For the latter, a thin section of the cracked glass sample has been digitized to provide essential information with regard to the geometry of the crack network. Together with the known physical properties of the intact glass matrix, this then allows for deriving a first-order 2D poroelastic model for the cracked sample based on Biot’s quasi-static equations.

Characterization of metal-containing amorphous hydrogenated carbon films

1992 ◽  
Vol 7 (3) ◽  
pp. 667-676 ◽  
Author(s):  
M. Wang ◽  
K. Schmidt ◽  
K. Reichelt ◽  
H. Dimigen ◽  
H. Hübsch
Keyword(s):  
Mechanical Properties ◽  
Critical Load ◽  
Young’S Modulus ◽  
Metal Concentration ◽  
Young's Modulus ◽  
Protective Coatings ◽  
Mass Density ◽  
Carbon Films ◽  
Elastic Recoil ◽  
Amorphous Hydrogenated Carbon

Metal-containing amorphous hydrogenated carbon (Me–C: H) films were prepared on silicon substrates. Two kinds of metals (Ti, Ta) were incorporated in the process of reactive rf diode— (13.56 MHz) and DC-magnetron sputtering, respectively. Elastic recoil detection (ERD) and Rutherford backscattering (RBS) of MeV He+ ions were used to determine the hydrogen content and mass density of Me–C: H films. The mechanical properties, i.e., microhardness, Young's modulus, and adhesion, were measured with the help of a nanoindenter and scratch tester. Results show that (1) the mechanical properties of Me–C: H films depend mainly on metal concentrations. At a certain metal concentration, optimal hardness, Young's modulus, and critical load were obtained; (2) the M–C: H films with an optimal metal concentration possess similar hardness, Young's modulus, and higher critical load compared with the corresponding values of diamond-like carbon (a–C: H) films, due to the improvement of the toughness of the films by the incorporation of metals. Therefore, Me–C: H films show high promise of being wear-resistant protective coatings.

Investigation into the Dynamic Fracture Properties of Large Scale Functionally Graded Materials

2006 ◽  
Vol 324-325 ◽  
pp. 239-242 ◽  
Author(s):  
Xiao Bin Yang ◽  
Zhuo Zhuang ◽  
Xue Feng Yao
Keyword(s):  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Large Scale ◽  
Young's Modulus ◽  
Mass Density ◽  
Poisson's Ratio ◽  
Constant Mass ◽  
Functionally Gradient Materials ◽  
Gradient Materials ◽  
Functionally Gradient

A crack propagation perpendicular to gradient in a large scale functionally gradient materials, which has (1) a linear variation of Young’s modulus with a constant mass density and Poisson’s ratio, and (2) a exponential variation of Young’s modulus with a constant mass density and Poisson’s ratio, is modelled by finite element methods. Based on the experimental result of large scale functionally gradient materials, the dynamic propagation process of the FGMs is modelled and the dynamic parameters, like the energy release rate and crack tip opening angle, are calculated through a generation phase.

scholarly journals Vibration analysis of functionally graded materials for cylinder liner used in agricultural engine part

2019 ◽  
Vol 4 (1) ◽  
pp. 258-266
Author(s):  
Anand Prakash ◽  
Shiv Ranjan Kumar ◽  
Rahul Verma
Keyword(s):  
Boundary Conditions ◽  
Young’S Modulus ◽  
Vibration Analysis ◽  
Young's Modulus ◽  
Mass Density ◽  
Cylinder Liner ◽  
Functionally Graded ◽  
Power Exponent ◽  
Modulus Ratio ◽  
Engine Part

AbstractThe engine part is one of the major sources of vibration of agricultural machinery such as a tractor. Therefore, vibration analysis of agricultural engine part will improve the engine efficiency and agricultural performance. The main objective of present work was to study the dynamic behavior of functionally graded (FG) structural material for the application as cylinder liner as agricultural engine part. The vibration analysis of functionally graded (FG) beam was performed using Finite Element Method (FEM). A typical simply-supported FG beam was modeled in COMSOL Software, where the upper portion of the beam was alumina and the lower portion was steel. The basic properties of material such as Young’s Modulus and mass density were varied along the thickness according to the power law. The boundary conditions were also modeled, and parametric study was carried out with mass density and young’s modulus. Eigen value problem was solved and in turn natural frequency and mode shapes were obtained. The frequency ratio was calculated and compared for various boundary conditions. The finding of the results indicated that when power exponent was increased from 0 to 5, the nonlinear reduction in frequency was occurred but when power exponent was increased from 5 to 10, linear reduction in frequency was occurred. Also, the increase in power exponent caused the increase in frequency for Young’s Modulus ratio of 0.25 and 0.5, decrease in frequency for Young’s Modulus ratio of 2 and 4 and no change occurred for Young’s Modulus ratio of 1. The first non-dimensional frequency for Clamped-Clamped boundary condition was comparatively more than other boundary conditions and lowest frequency is obtained for Clamped –Free boundary conditions.

A Nondestructive Method for Probing Mechanical Properties of a Thin Film Using Impacts with Nanoclusters

2016 ◽  
Vol 08 (03) ◽  
pp. 1650041 ◽  
Author(s):  
Norio Inui ◽  
Kozo Mochiji ◽  
Kousuke Moritani
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Mass Density ◽  
Target Surface ◽  
Nondestructive Method ◽  
Thin Metallic Film ◽  
Cluster Ion ◽  
The Impact

The impact of an argon (Ar)-cluster ion on a thin film is evaluated in order to investigate a new method for probing the mechanical properties of the thin metallic film. Using a molecular dynamic (MD) method, we show that an Ar nanocluster ion with an incident velocity of 4[Formula: see text]km/s dissociates in approximately 1[Formula: see text]ps without sputtering the atoms of a target sample. After the impact, the Ar ion is scattered from the target surface with several neutral Ar atoms. The number of neutral atoms combining with the Ar ion and the velocity of the Ar ion depend on the mass density and Young’s modulus of the target. Analyzing these dependencies, we find that the mass density and Young’s modulus of thin films can be simultaneously determined by measuring the mass and velocity of the Ar-cluster ion scattered from the sample surface.

Effect of Carbon Black on Poisson's Ratio of Elastomers

1975 ◽  
Vol 48 (2) ◽  
pp. 246-253 ◽  
Author(s):  
B. P. Holownia
Keyword(s):  
Carbon Black ◽  
Bulk Modulus ◽  
Experimental Method ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Carbon Black Content ◽  
Practical Applications ◽  
Incompressible Materials

Abstract The experimental method developed is mostly suitable for measuring K of relatively incompressible materials such as members of the elastomer family. The accuracy of K values are estimated to be within ±3% for all rubber specimens. Its use can be extended to plastics with somewhat reduced accuracy. The results show that bulk modulus K for the four different rubbers tested increases almost linearly with carbon black content while the Young's modulus E increases much more rapidly as shown in Figure 3. It is interesting to note that Poisson's ratio v calculated using K and E does not fall below 0.4940 (Figure 5), and the value of v=0.4997 as quoted in engineering handbooks would be reasonable to use for most practical applications where the carbon black content is not excessive.

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