Dr. Dimitris C. Lagoudas Profile

Dr. Dimitris C. Lagoudas

John and Bea Slattery Chair of Aerospace Engg at Texas A&M Univ

SPIE Involvement:

Conference Program Committee | Conference Chair | Symposium Chair | Author

Publications (85)

PROCEEDINGS ARTICLE | March 22, 2018

Corrosion monitoring of NiTi alloy with small-amplitude potential intermodulation technique

Proc. SPIE. 10596, Behavior and Mechanics of Multifunctional Materials and Composites XII

KEYWORDS: Polarization, Electrodes, Metals, Corrosion, Nondestructive evaluation, Intermodulation, Shape memory alloys, Temperature metrology

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PROCEEDINGS ARTICLE | March 22, 2018

Experimental and numerical investigation of the stable crack growth regime under pseudoelastic loading in shape memory alloys

Proc. SPIE. 10596, Behavior and Mechanics of Multifunctional Materials and Composites XII

KEYWORDS: Aerospace engineering, Materials science, Numerical analysis, Finite element methods, Mechanical engineering, Shape memory alloys

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PROCEEDINGS ARTICLE | March 22, 2018

Damage evolution during actuation fatigue in shape memory alloys (SPIE Best Student Paper Award)

Proc. SPIE. 10596, Behavior and Mechanics of Multifunctional Materials and Composites XII

KEYWORDS: Actuators, X-ray computed tomography, Digital image correlation, Shape memory alloys

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PROCEEDINGS ARTICLE | March 15, 2018

Constitutive response of precipitation hardened Ni-Ti-Hf shape memory alloys through micromechanical modeling

Proc. SPIE. 10595, Active and Passive Smart Structures and Integrated Systems XII

KEYWORDS: Actuators, Aerospace engineering, Calibration, Diffusion, Heat treatments, Finite element methods, Shape memory alloys

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PROCEEDINGS ARTICLE | April 11, 2017

Predicting the constitutive response of precipitation hardened NiTiHf

Proc. SPIE. 10165, Behavior and Mechanics of Multifunctional Materials and Composites 2017

KEYWORDS: Actuators, Titanium, Image processing, Particles, Nickel, Diffusion, Heat treatments, Transmission electron microscopy, Chemical elements, Hafnium, Systems modeling, Shape memory alloys

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PROCEEDINGS ARTICLE | April 11, 2017

Influence of stress concentrations on failure of shape memory alloy actuators

Proc. SPIE. 10165, Behavior and Mechanics of Multifunctional Materials and Composites 2017

KEYWORDS: Actuators, Mechanics, Crystals, Manufacturing, Solids, Digital image correlation, Spherical lenses, Failure analysis, Shape memory alloys, Temperature metrology

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PROCEEDINGS ARTICLE | April 10, 2017

Recent developments on SMA actuators: predicting the actuation fatigue life for variable loading schemes

Proc. SPIE. 10172, A Tribute Conference Honoring Daniel Inman

KEYWORDS: Actuators, LabVIEW, Data modeling, Aerospace engineering, Calibration, Metals, Nickel, Heat treatments, Control systems, Smart materials, Shape memory alloys

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PROCEEDINGS ARTICLE | April 21, 2016

Fracture toughness of shape memory alloy actuators: effect of transformation-induced plasticity

Proc. SPIE. 9800, Behavior and Mechanics of Multifunctional Materials and Composites 2016

KEYWORDS: Actuators, Atrial fibrillation, Aerospace engineering, Crystals, Numerical analysis, Finite element methods, Solid state physics, Solid state electronics, Failure analysis, Thermodynamics, Prototyping, Shape memory alloys, Temperature metrology, Absorption

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PROCEEDINGS ARTICLE | April 18, 2016

Actuator lifetime predictions for Ni60Ti40 shape memory alloy plate actuators

Proc. SPIE. 9800, Behavior and Mechanics of Multifunctional Materials and Composites 2016

KEYWORDS: Mathematical modeling, Actuators, Thermography, Infrared sensors, Infrared imaging, Biomedical optics, Data modeling, Aerospace engineering, Calibration, Mathematics, Digital image correlation, Solid state physics, Failure analysis, Systems modeling, Shape memory alloys

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PROCEEDINGS ARTICLE | April 2, 2015

Modeling and development of a twisting wing using inductively heated shape memory alloy actuators

Proc. SPIE. 9431, Active and Passive Smart Structures and Integrated Systems 2015

KEYWORDS: Actuators, Aerospace engineering, Sensors, Skin, Manufacturing, 3D modeling, Finite element methods, Electromagnetism, Prototyping, Shape memory alloys

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PROCEEDINGS ARTICLE | April 1, 2015

Modeling of thermo-mechanical fatigue and damage in shape memory alloy axial actuators

Proc. SPIE. 9432, Behavior and Mechanics of Multifunctional Materials and Composites 2015

KEYWORDS: Actuators, LabVIEW, Aerospace engineering, Calibration, Control systems, Stationary wavelet transform, Solid state physics, Failure analysis, Systems modeling, Shape memory alloys

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PROCEEDINGS ARTICLE | April 10, 2014

The importance of interfacial resistance on the thermal behavior of carbon nanofiber/epoxy composites

Proc. SPIE. 9061, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2014

KEYWORDS: Carbon, Composites, Interfaces, Resistance, Thermal effects, Finite element methods, Nanofibers, Heat flux, Nanocomposites, Thermal modeling

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PROCEEDINGS ARTICLE | March 10, 2014

Stable crack growth during actuation in shape memory alloys

Proc. SPIE. 9058, Behavior and Mechanics of Multifunctional Materials and Composites 2014

KEYWORDS: Finite element methods, Shape memory alloys

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PROCEEDINGS ARTICLE | March 9, 2014

Modeling size effect in the SMA response: a gradient theory

Proc. SPIE. 9058, Behavior and Mechanics of Multifunctional Materials and Composites 2014

KEYWORDS: Shape memory alloys

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PROCEEDINGS ARTICLE | March 9, 2014

Folding patterns and shape optimization using SMA-based self-folding laminates

Proc. SPIE. 9057, Active and Passive Smart Structures and Integrated Systems 2014

KEYWORDS: Genetic algorithms, Atrial fibrillation, Data modeling, Composites, Manufacturing, Finite element methods, Algorithm development, Space operations, Optimization (mathematics), Shape memory alloys

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PROCEEDINGS ARTICLE | March 30, 2012

Design of shape memory alloy pipe couplers: modeling and experiments

Proc. SPIE. 8343, Industrial and Commercial Applications of Smart Structures Technologies 2012

KEYWORDS: Atrial fibrillation, Manufacturing, Resistance, Heat treatments, 3D modeling, Finite element methods, Niobium, Thermal modeling, Shape memory alloys, Temperature metrology

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PROCEEDINGS ARTICLE | March 28, 2012

Phenomenological modeling of induced transformation anisotropy in shape memory alloy actuators

Proc. SPIE. 8342, Behavior and Mechanics of Multifunctional Materials and Composites 2012

KEYWORDS: Actuators, Atrial fibrillation, Calibration, Materials processing, Fourier transforms, 3D modeling, Finite element methods, Thermodynamics, Shape memory alloys, Anisotropy

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PROCEEDINGS ARTICLE | March 23, 2012

Modeling fluid structure interaction with shape memory alloy actuated morphing aerostructures

Proc. SPIE. 8343, Industrial and Commercial Applications of Smart Structures Technologies 2012

KEYWORDS: Actuators, Computational fluid dynamics, Data modeling, Calibration, 3D modeling, Solids, Finite element methods, Fluid dynamics, Prototyping, Shape memory alloys

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PROCEEDINGS ARTICLE | April 28, 2011

Virtual processing of hybrid SMA composites through martensitic transformation

Proc. SPIE. 7978, Behavior and Mechanics of Multifunctional Materials and Composites 2011

KEYWORDS: Metals, Matrices, X-rays, Ceramics, Composites, Manufacturing, Tomography, Analytical research, Shape memory alloys, Multifunctional materials

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PROCEEDINGS ARTICLE | April 28, 2011

Model predictions of strain and magnetization responses under magneto-thermo-mechanical loading paths in magnetic shape memory alloys

Proc. SPIE. 7978, Behavior and Mechanics of Multifunctional Materials and Composites 2011

KEYWORDS: Data modeling, Calibration, Magnetism, 3D modeling, Thermal effects, Technetium, Thermodynamics, Shape memory alloys, Temperature metrology, Anisotropy

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PROCEEDINGS ARTICLE | April 28, 2011

Analysis and optimization of improved hybrid SMA flexures for high rate actuation

Proc. SPIE. 7979, Industrial and Commercial Applications of Smart Structures Technologies 2011

KEYWORDS: Actuators, Aerospace engineering, Copper, Silver, Thermal effects, Finite element methods, Aluminum, Optimization (mathematics), Thermal modeling, Shape memory alloys

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The utilization of shape memory alloys (SMAs) as actuators in aerospace applications continues to show promise. These materials, when subjected to controlled changes in temperature, have the capability to provide motion while under loads that exceed thousands of times their own weight and can do so over tens of thousands of cycles. However, the rate of thermally-induced SMA transformation is significantly hindered by low thermal conductivity and latent heat effects observed in this material. The relatively long cooling times observed in SMA geometries such as beams and tubes make it difficult for controlled devices to operate with sufficiently high frequency. Therefore, the application of SMA beams as aerospace control actuators has been limited. Morphing structures such as flight control mechanisms require higher cyclic actuation frequencies than are commonly observed in SMAs, and thus have motivated the effort to increase thermal actuation rates attainable in SMA active components. This work presents an analytical study of a tapered beam actuator and discusses the possibility of using SMAs in conjunction with more conductive materials to enhance actuation performance, especially with regard to actuation cyclic frequency. The analysis involves computing the actuation work output over time of various loaded, thermally cycled active SMA beams using an accurate constitutive model implemented in a finite element framework. This set of analyses considers the solution to a transient thermomechanically coupled problem and includes the effects of latent heat of transformation on the energy balance. The study compares the effectiveness of aluminum, copper, and silver secondary material regions and their geometric configurations in altering the actuation power-to-mass ratio of the beam. An optimization scheme is used to determine the geometric distribution of each secondary material that results in the highest power-to-mass ratio. It is shown that aluminum, when optimally distributed, provides the best overall design solution of the three materials considered.

PROCEEDINGS ARTICLE | April 27, 2011

The influence of stress and temperature on the residual strain generated during pseudoelastic cycling of NiTi SMA wires

Proc. SPIE. 7978, Behavior and Mechanics of Multifunctional Materials and Composites 2011

KEYWORDS: Atrial fibrillation, Custom fabrication, Aerospace engineering, Mechanics, Composites, Heat treatments, Calorimetry, Shape memory alloys, Multifunctional materials, Temperature metrology

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PROCEEDINGS ARTICLE | March 31, 2010

Constitutive modeling of magneto-mechanical coupling response of magnetic field-induced phase transformations in NiMnCoIn magnetic shape memory alloys

Proc. SPIE. 7644, Behavior and Mechanics of Multifunctional Materials and Composites 2010

KEYWORDS: Data modeling, Ferromagnetics, Sensors, Calibration, Magnetism, Thermal effects, Magnetic sensors, Thermodynamics, Shape memory alloys, Temperature metrology

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PROCEEDINGS ARTICLE | March 31, 2010

Stability of the magnetomechanical problem in magnetic shape memory alloys

Proc. SPIE. 7644, Behavior and Mechanics of Multifunctional Materials and Composites 2010

KEYWORDS: Data modeling, Materials processing, Magnetism, Free space, Numerical analysis, Finite element methods, Analytical research, Magnetostrictive materials, Shape memory alloys, Maxwell's equations

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PROCEEDINGS ARTICLE | March 31, 2010

3D finite element analysis of indentation recovery due to the shape memory effect

Proc. SPIE. 7644, Behavior and Mechanics of Multifunctional Materials and Composites 2010

KEYWORDS: Actuators, Atrial fibrillation, Materials processing, 3D modeling, Numerical analysis, Finite element methods, Shape analysis, Chemical elements, Spherical lenses, Shape memory alloys

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PROCEEDINGS ARTICLE | March 31, 2010

Phase transformation and creep behavior in Ti50Pd30Ni20 high temperature shape memory alloy in compression

Proc. SPIE. 7644, Behavior and Mechanics of Multifunctional Materials and Composites 2010

KEYWORDS: Actuators, Polishing, Custom fabrication, Aerospace engineering, Diffusion, Sodium, Material characterization, Surface finishing, Shape memory alloys, Temperature metrology

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