Dynamic Magnetomechanical Properties of Terfenol-D/Epoxy 1-3 Particulate Composites

2002 ◽  
Author(s):  
Siu Wing Or ◽  
Geoffrey P. McKnight ◽  
Nersesse Nersessian ◽  
Gregory P. Carman
Keyword(s):  
Coupling Coefficient ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Bias Field ◽  
Particulate Composites ◽  
Dynamic Strain ◽  
Monolithic Material ◽  
Different Types ◽  
Strain Coefficient ◽  
Magnetomechanical Coupling

This paper describes the effect of particulate crystallographic orientation on the dynamic magnetomechanical properties of Terfenol-D/epoxy 1–3 magnetostrictive particulate composites. Two different types of composites with approximately 50% Terfenol-D volume fraction were fabricated for comparison with [112]-textured monolithic Terfenol-D. In the first type, needle-shaped, [112]-oriented particles cut from the monolithic Terfenol-D were used and in the second type, irregular-shaped, randomly oriented particles ball-milled from the monolithic material were employed. Elastic moduli (E33H and E33B), dynamic strain coefficient (d33), and magnetomechanical coupling coefficient (k33) were investigated as a function of bias field. Both composites demonstrate similar property trends with the negative-ΔE, d33, and k33 values maximizing near 30 kA/m. The maximum values achieved in the oriented type are up to 67% larger than the non-oriented type and approaches 65% of the monolithic Terfenol-D. The property improvement in the oriented type is shown to be attributed to [112] preferential particulate orientation.

Compression Studies on Particulate Composites of Ternary Al-Ti-Fe, and Quaternary Al-Ti-Fe-Nb and Al-Ti-Fe-Mn L12 Compounds

1990 ◽  
Vol 213 ◽  
Author(s):  
K.S. Kumar ◽  
M.S. Dipietro ◽  
J.D. Whittenberger
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
High Temperatures ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Strain Rates ◽  
Warm Temperature ◽  
Monolithic Material ◽  
Alloying Additions ◽  
Before And After

ABSTRACTCompression studies were conducted on monolithic and TiB2 particulatereinforced composites of AI22 Fe3 Ti8, both with and without minor quaternary alloying additions (2 at.% Nb and 2 at.% Mn) as a function of temperature and as a function of strain rate at high temperature. The volume fraction of reinforcement was varied between 0 and 20 percent. The particulate reinforcements were found to be effective in increasing ambient- and warm-temperature strength; at high temperatures, the monolithic material is stronger than the composites, although the composites are superior at slow strain rates. The microstructures of the monolithic and composite specimens were examined before and after deformation to explain these observations.

Dynamic Characteristics of Tb-Dy-Fe Polycrystals with Axial Alignment

2005 ◽  
Vol 475-479 ◽  
pp. 2251-2254 ◽  
Author(s):  
Bo Wen Wang ◽  
L. Weng ◽  
S.Y. Li ◽  
S.Z. Zhou ◽  
I. Gyuro
Keyword(s):  
Magnetic Fields ◽  
Dynamic Characteristics ◽  
Coupling Coefficient ◽  
Dynamic Strain ◽  
Magnetization Process ◽  
Standard Strain ◽  
Mechanical Coupling ◽  
Axial Alignment ◽  
Strain Coefficient ◽  
Lock In

The magnetostriction and dynamic characteristics of Tb0.27Dy0.73Fe2 polycrystals with <110> axial alignment were investigated by standard strain gauge, two coil induction and lock-in amplifier techniques. It is found that the magnetostriction of the sample quickly increases with increasing magnetic fields when H≤80 kA/m under a pressure of 5 or 10 MPa and a “jump” effect occurs during the magnetization process. The dynamic strain coefficient, d33, dynamic incremental permeability,μ33, and magneto-mechanical coupling coefficient, k33, for the Tb0.3Dy0.7Fe2 rod polycrystal sample with <110> axial alignment were measured and discussed. The Tb0.27Dy0.73Fe2 polycrystals with <110> axial alignment possesses excellent magnetostrictive properties along the <110> rod direction in low magnetic fields and it is very useful in application of industry.

Compression behavior of TiB2-particulate-reinforced composites of Al22Fe3Ti8

1991 ◽  
Vol 6 (3) ◽  
pp. 530-538 ◽  
Author(s):  
M.S. DiPietro ◽  
K.S. Kumar ◽  
J.D. Whittenberger
Keyword(s):  
Strain Rate ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Strain Rates ◽  
Monolithic Material ◽  
Compression Behavior ◽  
Dominant Deformation Mechanism ◽  
Compressive Flow ◽  
Particulate Reinforced Composites ◽  
Particulate Reinforced

The compression behavior of both the monolithic L12 compound Al22Fe3Ti8 and discontinuous composites obtained by incorporating ∼1 μm TiB2 particles was studied for various volume percent reinforcements as a function of temperature and at high temperatures as a function of strain rate. In this study, by varying the Fe and Ti contents, the nature and volume fraction of the minor phases coexisting with the dominant L12 phase were changed and were examined with and without TiB2 reinforcement. At high strain rates (10−4 s−1), the TiB2 reinforcements significantly enhance ambient and warm-temperature strength, although a crossover is observed at ∼1000 K, above which the monolithic material is stronger than the composite. At slow strain rates (10−7 s−1), representative of creep conditions, however, the TiB2-containing composites retain their superiority at least up to 1200 K. Power law fits of compressive flow stress at 1% strain versus strain rate yielded a stress exponent of ∼3.0 with an activation energy of 310 kJ/mol for the monolithic material. For the particulate composites (20 vol. % TiB2), the corresponding values were ∼5.0 and 465 kJ/mol, suggesting a change in the dominant deformation mechanism.

scholarly journals Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2143
Author(s):  
Shaimaa I. Gad ◽  
Mohamed A. Attia ◽  
Mohamed A. Hassan ◽  
Ahmed G. El-Shafei
Keyword(s):  
Finite Element ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Zone Method ◽  
Stress Strain ◽  
The Matrix

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

scholarly journals Sensitivity of Ultrasonic Coda Wave Interferometry to Material Damage—Observations from a Virtual Concrete Lab

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4033
Author(s):  
Claudia Finger ◽  
Leslie Saydak ◽  
Giao Vu ◽  
Jithender J. Timothy ◽  
Günther Meschke ◽  
...  
Keyword(s):  
Elastic Moduli ◽  
Concrete Specimen ◽  
Coda Wave ◽  
Velocity Change ◽  
Damage Scenarios ◽  
Different Types ◽  
Source Signal ◽  
The Impact ◽  
Structural Scale ◽  
Coda Wave Interferometry

Ultrasonic measurements are used in civil engineering for structural health monitoring of concrete infrastructures. The late portion of the ultrasonic wavefield, the coda, is sensitive to small changes in the elastic moduli of the material. Coda Wave Interferometry (CWI) correlates these small changes in the coda with the wavefield recorded in intact, or unperturbed, concrete specimen to reveal the amount of velocity change that occurred. CWI has the potential to detect localized damages and global velocity reductions alike. In this study, the sensitivity of CWI to different types of concrete mesostructures and their damage levels is investigated numerically. Realistic numerical concrete models of concrete specimen are generated, and damage evolution is simulated using the discrete element method. In the virtual concrete lab, the simulated ultrasonic wavefield is propagated from one transducer using a realistic source signal and recorded at a second transducer. Different damage scenarios reveal a different slope in the decorrelation of waveforms with the observed reduction in velocities in the material. Finally, the impact and possible generalizations of the findings are discussed, and recommendations are given for a potential application of CWI in concrete at structural scale.

scholarly journals The Influence of Different Types of Nanofluid on Thermal and Fluid Flow Performance of Liquid Cold Plate

2018 ◽  
Vol 7 (4.35) ◽  
pp. 148 ◽  
Author(s):  
Nur Irmawati Om ◽  
Rozli Zulkifli ◽  
P. Gunnasegaran
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Steady State ◽  
Pressure Drop ◽  
Volume Fraction ◽  
Cold Plate ◽  
Governing Equations ◽  
Flow And Heat Transfer ◽  
Different Types ◽  
Volume Method

The influence of utilizing different nanofluids types on the liquid cold plate (LCP) is numerically investigated. The thermal and fluid flow performance of LCP is examined by using pure ethylene glycol (EG), Al2O3-EG and CuO-EG. The volume fraction of the nanoparticle for both nanofluid is 2%. The finite volume method (FVM) has been used to solved 3-D steady state, laminar flow and heat transfer governing equations. The presented results indicate that Al2O3-EG able to provide the lowest surface temperature of the heater block followed by CuO-EG and EG, respectively. It is also found that the pressure drop and friction factor are higher for Al2O3-EG and CuO-EG compared to the pure EG.

Impact Properties of Syntactic Foams and Effect of Microballoon Wall Thickness

2006 ◽  
Author(s):  
Tien-Chih Lin ◽  
Nikhil Gupta
Keyword(s):  
Impact Strength ◽  
Total Energy ◽  
Energy Absorption ◽  
Volume Fraction ◽  
Impact Testing ◽  
Syntactic Foams ◽  
Lower Strength ◽  
Impact Properties ◽  
Different Types ◽  
Pendulum Impact

Hollow particle (microballoon) filled polymeric composites, called syntactic foams, are tested for impact properties in the present work. Izod type pendulum impact testing is carried out on eight types of foams, which are made of four types of microballoons used in volume fractions of 0.5 and 0.6. Variation in the volume fraction of microballoons leads to a difference in the total energy absorbed during fracture of different types of foams. Results show that syntactic foams containing microballoons of lower density show lower impact strength because of the lower strength of these microballoons. An increase in microballoon volume fraction leads to decreased energy absorption and strength.

scholarly journals Effects of Polydispersity on the Phase Behavior of Additive Hard Spheres in Solution

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1543
Author(s):  
Luka Sturtewagen ◽  
Erik van der Linden
Keyword(s):  
Phase Behavior ◽  
Critical Point ◽  
Volume Fraction ◽  
Hard Spheres ◽  
Second Virial Coefficient ◽  
Two Phase ◽  
Different Types ◽  
Asymmetric Partitioning ◽  
Average Size ◽  
Liquid Liquid Phase Separation

The ability to separate enzymes, nucleic acids, cells, and viruses is an important asset in life sciences. This can be realised by using their spontaneous asymmetric partitioning over two macromolecular aqueous phases in equilibrium with one another. Such phases can already form while mixing two different types of macromolecules in water. We investigate the effect of polydispersity of the macromolecules on the two-phase formation. We study theoretically the phase behavior of a model polydisperse system: an asymmetric binary mixture of hard spheres, of which the smaller component is monodisperse and the larger component is polydisperse. The interactions are modelled in terms of the second virial coefficient and are assumed to be additive hard sphere interactions. The polydisperse component is subdivided into sub-components and has an average size ten times the size of the monodisperse component. We calculate the theoretical liquid–liquid phase separation boundary (the binodal), the critical point, and the spinodal. We vary the distribution of the polydisperse component in terms of skewness, modality, polydispersity, and number of sub-components. We compare the phase behavior of the polydisperse mixtures with their concomittant monodisperse mixtures. We find that the largest species in the larger (polydisperse) component causes the largest shift in the position of the phase boundary, critical point, and spinodal compared to the binary monodisperse binary mixtures. The polydisperse component also shows fractionation. The smaller species of the polydisperse component favor the phase enriched in the smaller component. This phase also has a higher-volume fraction compared to the monodisperse mixture.

Measurement and Analysis of Triboelectric Surface Charge

2021 ◽  
Vol 30 (1/2) ◽  
pp. 7-11
Author(s):  
Jinhong PARK ◽  
Jinhyeok CHOI ◽  
Sang Hyeok PARK ◽  
Minbaek LEE
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Surface Properties ◽  
Elastic Moduli ◽  
Surface Charges ◽  
Contact Electrification ◽  
Measurement And Analysis ◽  
Different Types ◽  
Triboelectric Charging ◽  
Method Of Measurement

Contact electrification occurs when two isolated objects come into contact. Such a phenomenon led humans to first realization of the existence of electricity. Until now, the main causes of the triboelectric charging phenomenon have generally been thought to be the transfer of electrons, ions, and materials. This article, however, is limited to electron transfer on the surface, which is regarded as a general case not limited to specific situations. The contact between two objects occurs between the two surfaces; therefore, the surface properties of the material under examination are the most important properties in triboelectric charge transfer. The surface properties may include the types of materials in contact, their energy states, the roughnesses of their surfaces, and their elastic moduli. In this regard, we introduce here the current understanding of the energy band structures involved in the different types of materials, the method of measurement, an analysis of surface charges, and related applications.

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