Dr. LeAnn E. Faidley Profile

Dr. LeAnn E. Faidley

Assistant Professor at Wartburg College

SPIE Involvement:

Author

Proceedings Article | 28 March 2012 Paper

Microstructure-based modeling of magneto-rheological elastomers

Yi Han, Zihou Zhang, LeAnn Faidley, Wei Hong

Proceedings Volume 8342, 83421B (2012) https://doi.org/10.1117/12.925492

KEYWORDS: Magnetism, Particles, Polymers, Solids, Composites, Solid modeling, Iron, Finite element methods, Matrices, Magnetorheological finishing

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Proceedings Article | 28 April 2011 Paper

Rate dependent finite deformation of magneto-active polymers

Yi Han, Wei Hong, LeAnn Faidley

Proceedings Volume 7978, 797819 (2011) https://doi.org/10.1117/12.884620

KEYWORDS: Magnetism, Polymers, Particles, Thermodynamics, 3D modeling, Iron, Matrices, Interfaces, Smart materials, Actuators

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Proceedings Article | 29 March 2010 Paper

Bulk motion for ultrasonic-assisted microforming using Terfenol-D

Adam Witthauer, LeAnn Faidley, Gap-Yong Kim

Proceedings Volume 7645, 76450N (2010) https://doi.org/10.1117/12.848287

KEYWORDS: Transducers, Finite element methods, Tolerancing, Ultrasonics, Surface finishing, Magnetostrictive materials, Control systems, Solid state physics, Actuators, Motion analysis

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Proceedings Article | 1 April 2009 Paper

Lumped parameter modeling of the actuator behavior of ferrogels

LeAnn Faidley, Elease McLaurin

Proceedings Volume 7289, 72891T (2009) https://doi.org/10.1117/12.816040

KEYWORDS: Magnetism, Particles, Data modeling, Statistical modeling, Actuators, Iron, Mathematical modeling, Composites, Sodium, Solids

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Proceedings Article | 2 April 2008 Paper

Characterization of the actuator behavior of blended-system ferrogels

Geunhyung Park, Elease McLaurin, LeAnn Faidley

Proceedings Volume 6929, 69292C (2008) https://doi.org/10.1117/12.776352

KEYWORDS: Iron, Magnetism, Particles, Actuators, Sodium, Polymers, Smart materials, Artificial muscles, Electroactive polymers, Control systems

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Proceedings Article | 6 April 2006 Paper

A homogenized strain model for Ni-Mn-Ga driven with collinear field and stress

LeAnn Faidley, Marcelo Dapino, Gregory Washington

Proceedings Volume 6170, 617019 (2006) https://doi.org/10.1117/12.658706

KEYWORDS: Magnetism, Data modeling, Crystals, Nickel, Manganese, Gallium, Optimization (mathematics), Stochastic processes, Homogenization, Transducers

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Ferromagnetic Shape Memory Alloys (FSMAs) in the nickel manganese gallium system have been shown to exhibit large magnetically induced strains of up to 9.5% due to magnetically driven twin variant reorientation. In order for this strain to be reversible, however, an external restoring stress or magnetic field needs to be applied orthogonal to the field and hence the implementation of Ni-Mn-Ga in applications involves the use of electromagnets, which tend to be heavy, bulky and narrowband. In previous work at The Ohio State University a sample of Ni₅₀Mn_28.7Ga_21.3 has been shown to exhibit reversible compressive strains of -4200 microstrain along its [001] direction when a magnetic field is applied along this same direction and no externally applied restoring force is present. This reversible strain is possible because of an internal stress field associated with pinning sites induced during manufacture of the crystal. This paper analyzes the switching between two variant orientations in the presence of magnetic fields (Zeeman energy) and pinning sites (pinning energy) through the formulation of a Gibbs energy functional for the crystal lattice. Minimization of the Gibbs free energy yields a strain kernel which represents the predicted behavior of an idealized 2-dimensional homogeneous single crystal with a single twin boundary and pinning site. While adequate, the kernel has limitations because it does not account for the following: (a) Ni-Mn-Ga consists of a large number of twin variants and boundaries, (b) the strength of the pinning sites may vary, and (c) the local and applied magnetic field will differ due to neighbor-to-neighbor interactions. These limiting factors are addressed in this paper by considering stochastic homogenization. Stochastic distributions are used on the interaction field and on the pinning site strength, yielding a phenomenological model for the bulk strain behavior of Ni₅₀Mn_28.7Ga_21.3. The model quantifies both the hysteresis and saturation of the strain. Constrained optimization is used to determine the necessary parameters and an error analysis is performed to assess the accuracy of the model for various loading conditions.

Proceedings Article | 16 May 2005 Paper

Reversible strain in Ni-Mn-Ga with collinear field and stress

LeAnn Faidley, Marcelo Dapino, Gregory Washington, Thomas Lograsso

Proceedings Volume 5761, (2005) https://doi.org/10.1117/12.600210

KEYWORDS: Magnetism, Nickel, Transducers, Manganese, Gallium, Shape memory alloys, Anisotropy, Data modeling, Motion models, Ferromagnetics

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Proceedings Article | 21 July 2004 Paper

Dynamic behavior and stiffness tuning in solenoid-based Ni-Mn-Ga transducers

LeAnn Faidley, Marcelo Dapino, Gregory Washington, Thomas Lograsso

Proceedings Volume 5387, (2004) https://doi.org/10.1117/12.540039

KEYWORDS: Magnetism, Transducers, Nickel, Gallium, Manganese, Actuators, Data acquisition, Crystals, Manufacturing, Ferromagnetics

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Proceedings Article | 1 August 2003 Paper

Analytical and experimental issues in Ni-Mn-Ga transducers

LeAnn Faidley, Marcelo Dapino, Gregory Washington, Thomas Lograsso, Ralph Smith

Proceedings Volume 5049, (2003) https://doi.org/10.1117/12.484011

KEYWORDS: Magnetism, Transducers, Nickel, Manganese, Gallium, Actuators, Shape memory alloys, Magnetostrictive materials, Amplifiers, Ferromagnetics

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Proceedings Article | 16 August 2001 Paper

Characterization of a small Terfenol-D transducer in mechanically blocked configuration

LeAnn Faidley, Marcelo Dapino, Alison Flatau

Proceedings Volume 4327, (2001) https://doi.org/10.1117/12.436563

KEYWORDS: Magnetism, Transducers, Magnetostrictive materials, Ferroelectric materials, Smart materials, Amplifiers, Crystals, Lithium, Anisotropy, Manufacturing

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