Anargyros Karakalas

Verified email at gmail.com

Post-Doctoral Researcher at the Aerospace Engineering Department
Texas A&M University



                                               

https://researchid.co/karakalas

RESEARCH INTERESTS

Shape Memory Alloys Constitutive Modeling
Morphing Structures
Smart Actuators
Finite Element Simulations

21

Scopus Publications

138

Scholar Citations

7

Scholar h-index

6

Scholar i10-index

Scopus Publications

  • ASMADA-A tool for automatic analysis of shape memory alloy thermal cycling data under constant stress
    Matthew C Kuner, Anargyros A Karakalas, and Dimitris C Lagoudas

    Smart Materials and Structures, ISSN: 09641726, eISSN: 1361665X, Published: December 2021 IOP Publishing
    Abstract The authors present the automatic shape memory alloy data analyzer (ASMADA). ASMADA is capable of rapid, robust, and consistent processing of shape memory alloy thermal cycling data acquired under constant stress. This seeks to address two primary issues: the lack of unified analysis procedures in relevant standards and the near-universal manual analysis of such data. ASMADA is compliant with the definitions provided in ASTM standards and calculates up to twenty-three (23) material properties/parameters at speeds ranging from 5 to 35 cycles s−1. These parameters include the four transformation start/finish temperature thresholds, which are calculated using the tangent line method; the transformation region tangent lines are determined using a modified sigmoid function, whereas the single-phase region tangent lines are determined based on the geometry of the cycle data. Additionally, a graphical user interface is provided to make the tool readily accessible and easy to navigate. The capabilities of ASMADA have been tested on experimental data from four different research groups; results from five of these tests are presented to demonstrate the tool’s robustness. This tool was developed in Python and is publicly available at https://github.com/matthewkuner/ASMADA

  • Finite Strain Constitutive Modelling of Shape Memory Alloys Considering Partial Phase Transformation with Transformation-Induced Plasticity
    Giulia Scalet, Anargyros Karakalas, Lei Xu, and Dimitris Lagoudas

    Shape Memory and Superelasticity, ISSN: 2199384X, eISSN: 21993858, Pages: 206-221, Published: June 2021 Springer Science and Business Media LLC
    AbstractThis paper presents a unified modelling effort to describe partial phase transformation during cyclic thermo-mechanical loading in Shape Memory Alloys (SMA). To this purpose, a three-dimensional (3D) finite strain constitutive model considering TRansformation-Induced Plasticity (TRIP) is combined with a modified hardening function to enable the accurate and efficient prediction of partial transformations during cyclic thermo-mechanical loading. The capabilities of the proposed model are demonstrated by predicting the behavior of the material under pseudoelastic and actuation operation using finite element analysis. Numerical results of the modified model are presented and compared with the original model without considering the partial transformation feature as well as with uniaxial actuation experimental data. Various aspects of cyclic material behavior under partial transformation are analyzed and discussed for different SMA systems.

  • Quantification of Shape Memory Alloy Damping Capabilities Through the Prediction of Inherent Behavioral Aspects
    Anargyros A. Karakalas, Theodoros T. Machairas, Dimitris C. Lagoudas, and Dimitris A. Saravanos

    Shape Memory and Superelasticity, ISSN: 2199384X, eISSN: 21993858, Pages: 7-29, Published: March 2021 Springer Science and Business Media LLC
    In this work the time response of pseudoelastic Shape Memory Alloy (SMA) wires is numerically simulated. In particular, the effect of their operation under partial phase transformation is investigated and quantified. Additionally, the effect of the thermomechanical coupling under cyclic operation is evaluated both under adiabatic and natural convection conditions. To this end, proper finite element models are generated considering a low-frequency harmonic sinusoidal excitation. The effect of the partial transformation and thermomechanical coupling on the operation of the SMA is highlighted by comparison with respective results acquired by finite element models which neglect the modified hardening function that accounts for the partial loops. The results suggest that the latent heat produced during forward transformation highly affects the energy dissipation potential of SMAs. The hardening behavior also affects the transformation evolution and therefore impacts the amount of heat generation/absorption. Although both phenomena, when accounted for, result in the prediction of an altered hysteresis area and consequently different dissipation capabilities, the scope of the paper is to highlight their importance on the calculated values of dissipated energy and loss factor. These quantities are of particular interest since they constitute crucial design parameters for the development of smart dampers employing SMA materials.

  • Parametric optimization of sma torsional actuators for aircraft morphing applications
    Christopher Summers, Jonathan M. Weaver-Rosen, Anargyros A. Karakalas, Richard J. Malak, and Dimitris C. Lagoudas

    ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), Published: 2021 American Society of Mechanical Engineers
    Abstract Novel design of more efficient, environmentally friendly, quiet, and cost-effective air transportation could be substantially benefited by introducing highly adaptive, multi-functional systems that are able to mimic the operation of biological systems, like birds. Altering the Outer Mold Line (OML) of an aircraft allows for achieving the optimal response under a wide range of operational conditions. In the framework of the “Adaptive Aerostructures for Revolutionary Civil Supersonic Transportation” project funded by NASA, an articulated panel mechanism controlled by Shape Memory Alloy (SMA) actuators is investigated as a means for reducing the perceived loudness of the sonic boom produced by a commercial aircraft when flying at supersonic speeds. A pair of SMA torque tubes is envisioned to induce the required rotation of the panels in order to achieve the desirable OML shapes. However, design objectives such as minimizing power consumption, mass, and cooling time are often competing and the selection of the optimal dimensions is neither elementary nor straightforward. In the research conducted herein, a case study is defined and realized for the optimal design of the SMA torque tubes as part of a larger morphing structure. In the early stages of design, engineers are often faced with the challenge of making decisions with incomplete information. For example, the designer must know the aerodynamic loads to choose the optimal dimensions, but the aerodynamic loads depend on aircraft dimensions. To enable detailed optimization in the early design stages, parametric optimization can be used to solve for the parameterized Pareto frontier. This parameterized Pareto frontier allows a designer to explore how the traditional Pareto frontier might change as exogenous parameters (the values of which are not yet fully known) change. In this work, the design variables under the control of the engineer are the dimensions of the torque tube, i.e. length, inner diameter, and thickness. The objectives are to minimize cooling time and maximize rigidity. The exogenous parameters outside of the designer’s control include the required actuation stroke and aerodynamic forces. Results show the effects of parameters on the objective tradeoffs and demonstrate how an engineer can choose an optimal solution once the parameter values are known.

  • Numerical investigation of autonomous camber morphing of a helicopter rotor blade using shape memory alloys
    77th Annual Vertical Flight Society Forum and Technology Display, FORUM 2021: The Future of Vertical Flight, Published: 2021

  • Comparison of linear and torsional SMA actuators for morphing applications
    Wonjoon Suk, Anargyros A. Karakalas, and Dimitris C. Lagoudas

    Proceedings of SPIE - The International Society for Optical Engineering, ISSN: 0277786X, eISSN: 1996756X, Volume: 11588, Published: 2021 SPIE
    Multifunctional capabilities of Shape Memory Alloys (SMAs) and, more specifically, their inherent characteristic of producing and recovering transformation strain under thermal stimulus, render them ideal for actuator appli- cations. In fact, SMA actuators are widely used in various fields including but not limited to robotics, medical, civil, and aerospace engineering. Moreover, they are also able to be formed in a wide range of shapes that includes, but is not limited to, wires, ribbons, bars, torque tubes and various spring types. This fact combined with their high-energy density, the noise-less, spark-free, and debris-less operation and their compactness renders them ideal for aerospace morphing structures where weight, volume, energy consumption, and other operational specifications have to be strictly met. In this study, two SMA actuator forms, one linear, i.e., wires of circular cross-section, and one torsional, i.e., torque tubes, are compared in terms of weight/volume, stroke capabilities, developed stresses, cooling requirements, power consumption and overall operation under predefined conditions. The actuators are intended for use in parts of an articulated shape adaptive mechanism envisioned for altering locally the outer mold line of a civil supersonic aircraft. The morphing system is placed on the lower part of the fuselage in order to alter the aerodynamic profile and reduce the sonic boom created during supersonic flight over inhabited areas. The specifications for the design of the actuators are provided and finite element analysis is used to verify the overall response of the SMAs.

  • Preliminary design and numerical investigation of sma torsion tubes for the actuation of articulated adaptive panels
    AIAA Scitech 2021 Forum, Pages: 1-18, Published: 2021

  • Design of morphing strips using SMA actuators under partial phase transformation operation
    ASME 2020 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2020, Published: 2020

  • Tuning of shape memory polymer properties by controlling 3D printing strategy
    Alnto Koualiarella, Apostolos Arvanitidis, Apostolos Argyros, Charoula Kousiatza, Anargyros Karakalas, Dimitris Lagoudas, and Nikolaos Michailidis

    CIRP Annals, ISSN: 00078506, eISSN: 17260604, Pages: 213-216, Published: 2020 Elsevier BV
    Abstract Unique thermal shape recovery and chemical stability make Shape Memory Polymers (SMPs) attractive for critical applications in biomedical, aerospace and energy sectors. While additive manufacturing (AM) of SMPs allows fabrication of functionally-graded structures with tailored, intricate design features, the effect of AM on shape recovery characteristics has not received much attention. To demonstrate that shape recovery characteristics can be significantly enhanced through a variation of AM building strategies and process parameters beyond tuning of material compositions alone, an experimental study was developed. In-situ thermo-micro-mechanical testing was applied to capture the shape memory properties, both during shape programming and post that.

  • Effect of tension-compression asymmetry and partial transformation on the response of shape memory alloy beam structures
    Anargyros Karakalas and Dimitris Lagoudas

    Proceedings of SPIE - The International Society for Optical Engineering, ISSN: 0277786X, eISSN: 1996756X, Volume: 11377, Published: 2020 SPIE
    Shape Memory Alloys (SMAs) constitute a class of materials that are distinguished by their highly non-linear, thermo-mechanically coupled behaviour which is related with the phenomena accompanying the diffusion-less, solid-state phase transformation. This transition from the parent phase of Austenite to the product phase of Martensite and vice versa is also bound with the uncommon characteristic of “memory” exhibited when the material undergoes variable thermo-mechanical loadings. When a transformation reversal takes place, the material seems to inherently remember its state and adapts its future response in order to form closed paths, strongly dependent on the induced transformation history. Furthermore, another characteristic trait of SMAs is the asymmetry of their response when under tension or compression. During mixed loading states, such as bending of a beam, the evolution of transformation is observed to be different based on the sign of the load. The aforementioned peculiarities significantly affect the implementation SMAs in the design and realization of smart engineering structures intended for use in a wide range of fields that include but are not limited to aerospace, biomedical, wind energy, civil and automotive. To this end, efficient constitutive modeling of the phenomena related to the phase transformation is essential and of high importance in order to predict the complex performance of these materials. In this paper, emphasis is placed upon the investigation of the combined effect of tension-compression asymmetry and partial transformation on the response of SMA beams subjected to threepoint bending loading conditions. In this context, modeling of tension-compression asymmetry is investigated by using a set of different phase transformation functions based on the principles of computational plasticity, while a modified hardening function is considered to account for partial transformation behaviour. The produced numerical results are compared with respective cases that omit these phenomena in order to quantify their effect in terms of the developed stresses, material state and production/recovery of transformation strain.

  • Effect of shape memory alloy actuator geometric non-linearity and thermomechanical coupling on the response of morphing structures
    Theodoros T Machairas, Alexandros G Solomou, Anargyros A Karakalas, and Dimitris A Saravanos

    Journal of Intelligent Material Systems and Structures, ISSN: 1045389X, eISSN: 15308138, Pages: 2166-2185, Published: 1 August 2019 SAGE Publications
    The response of adaptive structures entailing shape memory alloy actuators is investigated both numerically and experimentally in this work. Emphasis is placed on the inclusion of large displacements and rotations, as well as thermomechanical coupling in the simulation of the shape memory alloy actuators. Reduced multi-field beam finite element models for shape memory alloy actuators, encompassing a co-rotational formulation for large displacements and capability to provide the thermomechanically coupled transient response, are briefly overviewed. Prototypes of two adaptive structure configurations are developed, experimentally characterized, and numerically modeled. The measured response of the two prototypes is correlated with respective numerical results that consider both the geometric non-linearity and the thermomechanical coupling of the shape memory alloy actuators. Hence, the influence of these two effects on the predicted response of both the actuator and the adaptive structure is demonstrated. The results quantify also the interactions between geometric non-linearity and thermomechanical coupling terms. As it is shown, better agreement with experimental data is obtained when considering both effects.

  • Effect of shape memory alloys partial transformation on the response of morphing structures encompassing shape memory alloy wire actuators
    Anargyros A Karakalas, Theodoros T Machairas, and Dimitris A Saravanos

    Journal of Intelligent Material Systems and Structures, ISSN: 1045389X, eISSN: 15308138, Pages: 1682-1698, Published: 1 July 2019 SAGE Publications
    The present article investigates and explores the effect of partial phase transformation on the response of shape adaptive/morphing structures controlled by shape memory alloy wire actuators subject to variable trajectory and high actuation speed requirements, where the effect of partial transformation becomes more dominant. A modified constitutive model is adopted for the prediction of the thermo-mechanically coupled response on a trailing edge shape adaptive rib prototype intended for active load alleviation in large wind turbine blades, and the simulated behavior is subsequently correlated with experimental results. The experimentally validated model is further used to predict the response of the full-scale camber-line adaptive structure with shape memory alloy Ni51Ti49 wt% actuators in antagonistic configurations, under demanding operational time target trajectories at extreme turbulence conditions. Comparison of the results, with a case that omits partial transformation behavior, reveals substantial improvements in the predicted target trajectories, actuation speed, actuator stresses, and required operational temperature variation. The latter discloses the enhanced potential of shape memory alloy actuators to provide higher transformation rate and possibly higher fatigue life combined with lower energy demands toward the design and realization of efficient morphing structures.

  • Active load alleviation potential of adaptive wind turbine blades using shape memory alloy actuators
    Anargyros A. Karakalas, Dimitris I. Manolas, Theodoros T. Machairas, Vasilis A. Riziotis, and Dimitris A. Saravanos

    Wind Energy, ISSN: 10954244, eISSN: 10991824, Pages: 620-637, Published: May 2019 Wiley

  • Modeling of partial transformation cycles of SMAs with a modified hardening function
    Anargyros A Karakalas, Theodoros T Machairas, Alexandros G Solomou, and Dimitris A Saravanos

    Smart Materials and Structures, ISSN: 09641726, eISSN: 1361665X, Published: 1 February 2019 IOP Publishing

  • Exploration of the partial transformation behaviour of shape memory alloys and its effect on actuation performance
    Anargyros A. Karakalas, Theodoros T. Machairas, and Dimitris Saravanos

    Proceedings of SPIE - The International Society for Optical Engineering, ISSN: 0277786X, eISSN: 1996756X, Volume: 10968, Published: 2019 SPIE
    Multiple applications of shape memory alloys (SMA) involve operation under partial transformation (PT), where reversal of the transformation direction takes place while the material is in a mixed phase state. Typical applications of SMAs include: actuators in adaptive/morphing structures which should repeatedly reach various target shapes or to follow time trajectories at higher time rates; dampers vibrating pseudo-elastically under varying amplitudes of dynamic loads. While the thermo-mechanically coupled behavior of SMAs under full transformation has been studied during the past and various models have been proposed, their response under PT has yet to receive the required attention to fully unravel the potential of these materials. In this paper, an experimental study of SMA wires under PT is presented along with a modified constitutive model. The physical constitutive model of Lagoudas et al.,1 is combined with a new expression of the hardening function to enable the accurate and efficient prediction of PT behaviour. The predicted PT response is correlated with isobaric, thermally induced PT cycle experiments. Very good agreement is obtained with measured partial cycles, especially for PT cycles formed near the middle of the major hysteresis loop. The new constitutive equations are included into a finite element framework to investigate the effect of PT on SMA actuation function in morphing airfoils for active load alleviation in large wind turbine blades, and numerical results are correlated with experimental data. The correlations prove the importance of PT behavior in the actuator performance of SMAs, resulting in substantially more accurate predictions in deformation, stress and temperature.

  • Robust fluid-structure interaction analysis of an adaptive airfoil using shape memory alloy actuators
    Theodoros Machairas, Alexandros Kontogiannis, Anargyros Karakalas, Alexandros Solomou, Vasilis Riziotis, and Dimitris Saravanos

    Smart Materials and Structures, ISSN: 09641726, eISSN: 1361665X, Published: 18 September 2018 IOP Publishing

  • Co-rotational thermo-mechanically coupled multi-field framework and finite element for the large displacement analysis of multi-layered shape memory alloy beam-like structures
    Alexandros G Solomou, Theodoros T Machairas, Anargyros A Karakalas, and Dimitris A Saravanos

    Smart Materials and Structures, ISSN: 09641726, eISSN: 1361665X, Published: 16 May 2017 IOP Publishing

  • Arobust fluid structure interaction numerical tool for the analysis of airfoil morphing structures with shape memory alloy actuators
    8th Conference on Smart Structures and Materials, SMART 2017 and 6th International Conference on Smart Materials and Nanotechnology in Engineering, SMN 2017, Volume: 2017-January, Pages: 1005-1017, Published: 2017

  • Assessment of fatigue load alleviation potential through blade trailing edge morphing
    Theofanis Tsiantas, Dimitris I. Manolas, Theodore Machairas, Anargyros Karakalas, Vasilis A. Riziotis, Dimitrios Saravanos, and Spyros G. Voutsinas

    Journal of Physics: Conference Series, ISSN: 17426588, eISSN: 17426596, Volume: 753, Published: 3 October 2016 IOP Publishing
    The possibility of alleviating wind turbine loads through blade trailing edge shape morphing is investigated in the present paper. Emphasis is put on analyzing the effect of the trailing edge flap geometry on load reduction levels. The choice of the shape deformation of the camber line as well as the chordwise and spanwise dimensions of the trailing edge flap are addressed. The analysis concerns the conceptual DTU 10 MW RWT. Aeroelastic control of loads is materialized through a standard individual flap controller. Furthermore, a comb ined individual pitch-flap controller is evaluated and found to present advantages compared to the flap only controller. Flapwise fatigue load reduction ranging from 10% to 20%, depending on wind velocity and configuration considered, is obtained. Better performance is achieved by the combined pitch-flap controller.

  • Development of SMA actuated morphing airfoil for wind turbine load alleviation
    A. Karakalas, T. Machairas, A. Solomou, V. Riziotis, and D. Saravanos

    Proceedings of the TMS Middle East - Mediterranean Materials Congress on Energy and Infrastructure Systems, MEMA 2015, Pages: 181-190, Published: 2015 John Wiley & Sons, Inc.

  • Design and simulation of morphing airfoil sections with SMA actuators for wind turbine rotors
    ICAST 2014 - 25th International Conference on Adaptive Structures and Technologies, Published: 2014

RECENT SCHOLAR PUBLICATIONS

  • Acknowledgment to Reviewers of Actuators in 2021
    A Eltaggaz, AK Petrovich, A Pena-Francesch, A Koszewnik, A Ghaffar, ...
    2022

  • Parametric Optimization of SMA Torsional Actuators for Aircraft Morphing Applications
    C Summers, JM Weaver-Rosen, AA Karakalas, RJ Malak Jr, ...
    ASME International Mechanical Engineering Congress and Exposition 85574 2021

  • ASMADA—A tool for automatic analysis of shape memory alloy thermal cycling data under constant stress
    MC Kuner, AA Karakalas, DC Lagoudas
    Smart Materials and Structures 30 (12), 125003 2021

  • Finite Strain Constitutive Modelling of Shape Memory Alloys Considering Partial Phase Transformation with Transformation-Induced Plasticity
    G Scalet, A Karakalas, L Xu, D Lagoudas
    Shape Memory and Superelasticity 7 (2), 206-221 2021

  • Comparison of linear and torsional SMA actuators for morphing applications
    W Suk, AA Karakalas, DC Lagoudas
    Active and Passive Smart Structures and Integrated Systems XV 11588, 155-169 2021

  • Quantification of Shape Memory Alloy Damping Capabilities Through the Prediction of Inherent Behavioral Aspects
    AA Karakalas, TT Machairas, DC Lagoudas, DA Saravanos
    Shape Memory and Superelasticity 7 (1), 7-29 2021

  • Numerical investigation of autonomous camber morphing of a helicopter rotor blade using shape memory alloys
    E Ferede, A Karakalas, F Gandhi, DC Lagoudas
    Proceedings of the 77th Annual Vertical Flight Society Forum and Technology 2021

  • Preliminary Design and Numerical Investigation of SMA Torsion Tubes for the Actuation of Articulated Adaptive Panels
    AA Karakalas, DC Lagoudas
    AIAA Scitech 2021 Forum, AIAA 2021-1318 2021

  • Design of morphing strips using sma actuators under partial phase transformation operation
    AA Karakalas, TT Machairas, DC Lagoudas, DA Saravanos
    Smart Materials, Adaptive Structures and Intelligent Systems 84027, V001T04A021 2020

  • Effect of tension-compression asymmetry and partial transformation on the response of shape memory alloy beam structures
    AA Karakalas, DC Lagoudas
    Behavior and Mechanics of Multifunctional Materials IX 11377, 168-182 2020

  • Tuning of shape memory polymer properties by controlling 3D printing strategy
    A Koualiarella, A Arvanitidis, A Argyros, C Kousiatza, A Karakalas, ...
    CIRP Annals 69 (1), 213-216 2020

  • Effect of shape memory alloy actuator geometric non-linearity and thermomechanical coupling on the response of morphing structures
    TT Machairas, AG Solomou, AA Karakalas, DA Saravanos
    Journal of Intelligent Material Systems and Structures 30 (14), 2166-2185 2019

  • Effect of shape memory alloys partial transformation on the response of morphing structures encompassing shape memory alloy wire actuators
    AA Karakalas, TT Machairas, DA Saravanos
    Journal of Intelligent Material Systems and Structures 30 (11), 1682-1698 2019

  • Active load alleviation potential of adaptive wind turbine blades using shape memory alloy actuators
    AA Karakalas, DI Manolas, TT Machairas, VA Riziotis, DA Saravanos
    Wind Energy 22 (5), 620-637 2019

  • Exploration of the partial transformation behaviour of shape memory alloys and its effect on actuation performance
    AA Karakalas, TT Machairas, DA Saravanos
    Behavior and mechanics of multifunctional materials XIII 10968, 83-97 2019

  • Modeling of partial transformation cycles of SMAs with a modified hardening function
    AA Karakalas, TT Machairas, AG Solomou, DA Saravanos
    Smart Materials and Structures 28 (3), 035014 2019

  • Thermomechanically coupled analysis and experimental investigation of morphing structures with shape memory alloy actuators operating under partial transformation with a focus
    A Karakalas
    Πανεπιστήμιο Πατρών. Σχολή Πολυτεχνική. Τμήμα Μηχανολόγων και Αεροναυπηγών 2019

  • Robust fluid-structure interaction analysis of an adaptive airfoil using shape memory alloy actuators
    T Machairas, A Kontogiannis, A Karakalas, A Solomou, V Riziotis, ...
    Smart Materials and Structures 27 (10), 105035 2018

  • Co-rotational thermo-mechanically coupled multi-field framework and finite element for the large displacement analysis of multi-layered shape memory alloy beam-like structures
    AG Solomou, TT Machairas, AA Karakalas, DA Saravanos
    Smart Materials and Structures 26 (6), 065028 2017

  • Effect of Shape Memory Alloy Partial Transformation on the Performance of Morphing Wind Turbine Airfoils
    A Karakalas, T Machairas, A Solomou, D Saravanos
    28th International Conference on Adaptive Structures and Technologies, ICAST 2017

MOST CITED SCHOLAR PUBLICATIONS

  • Modeling of partial transformation cycles of SMAs with a modified hardening function
    AA Karakalas, TT Machairas, AG Solomou, DA Saravanos
    Smart Materials and Structures 28 (3), 035014 2019
    Citations: 20

  • Active load alleviation potential of adaptive wind turbine blades using shape memory alloy actuators
    AA Karakalas, DI Manolas, TT Machairas, VA Riziotis, DA Saravanos
    Wind Energy 22 (5), 620-637 2019
    Citations: 17

  • Development of SMA actuated morphing airfoil for wind turbine load alleviation
    A Karakalas, T Machairas, A Solomou, V Riziotis, D Saravanos
    Proceedings of the TMS Middle East—Mediterranean Materials Congress on 2015
    Citations: 12

  • Effect of shape memory alloys partial transformation on the response of morphing structures encompassing shape memory alloy wire actuators
    AA Karakalas, TT Machairas, DA Saravanos
    Journal of Intelligent Material Systems and Structures 30 (11), 1682-1698 2019
    Citations: 11

  • Robust fluid-structure interaction analysis of an adaptive airfoil using shape memory alloy actuators
    T Machairas, A Kontogiannis, A Karakalas, A Solomou, V Riziotis, ...
    Smart Materials and Structures 27 (10), 105035 2018
    Citations: 11

  • Effect of shape memory alloy actuator geometric non-linearity and thermomechanical coupling on the response of morphing structures
    TT Machairas, AG Solomou, AA Karakalas, DA Saravanos
    Journal of Intelligent Material Systems and Structures 30 (14), 2166-2185 2019
    Citations: 10

  • Assessment of fatigue load alleviation potential through blade trailing edge morphing
    T Tsiantas, DI Manolas, T Machairas, A Karakalas, VA Riziotis, ...
    Journal of Physics: Conference Series 753 (4), 042020 2016
    Citations: 8

  • Co-rotational thermo-mechanically coupled multi-field framework and finite element for the large displacement analysis of multi-layered shape memory alloy beam-like structures
    AG Solomou, TT Machairas, AA Karakalas, DA Saravanos
    Smart Materials and Structures 26 (6), 065028 2017
    Citations: 7

  • Morphing Airfoil with Shape Memory Alloy Wire Actuators for Active Aerodynamic Load Control in Large Wind-Turbine Blades
    A Karakalas, T Machairas, A Solomou, V Riziotis, D Saravanos
    EWEA annual event, 17-20 2015
    Citations: 6

  • Design and simulation of morphing airfoil sections with sma actuators for wind turbine rotors
    A Karakalas, T Machairas, A Solomou, V Riziotis, D Saravanos
    Proc. ICAST 2014, 1-12 2014
    Citations: 6

  • Exploration of the partial transformation behaviour of shape memory alloys and its effect on actuation performance
    AA Karakalas, TT Machairas, DA Saravanos
    Behavior and mechanics of multifunctional materials XIII 10968, 83-97 2019
    Citations: 5

  • Effect of tension-compression asymmetry and partial transformation on the response of shape memory alloy beam structures
    AA Karakalas, DC Lagoudas
    Behavior and Mechanics of Multifunctional Materials IX 11377, 168-182 2020
    Citations: 4

  • Preliminary Design and Numerical Investigation of SMA Torsion Tubes for the Actuation of Articulated Adaptive Panels
    AA Karakalas, DC Lagoudas
    AIAA Scitech 2021 Forum, AIAA 2021-1318 2021
    Citations: 3

  • Tuning of shape memory polymer properties by controlling 3D printing strategy
    A Koualiarella, A Arvanitidis, A Argyros, C Kousiatza, A Karakalas, ...
    CIRP Annals 69 (1), 213-216 2020
    Citations: 3

  • Effect of Shape Memory Alloy Partial Transformation on the Performance of Morphing Wind Turbine Airfoils
    A Karakalas, T Machairas, A Solomou, D Saravanos
    28th International Conference on Adaptive Structures and Technologies, ICAST 2017
    Citations: 3

  • Thermomecanically Transient Response Prediction of Morphing Structures with Shape Memory Alloy Actuators
    AG Solomou, TT Machairas, AA Karakalas
    Proceedings of ICAST 2013, Aruba 2013
    Citations: 3

  • Numerical investigation of autonomous camber morphing of a helicopter rotor blade using shape memory alloys
    E Ferede, A Karakalas, F Gandhi, DC Lagoudas
    Proceedings of the 77th Annual Vertical Flight Society Forum and Technology 2021
    Citations: 2

  • Design of morphing strips using sma actuators under partial phase transformation operation
    AA Karakalas, TT Machairas, DC Lagoudas, DA Saravanos
    Smart Materials, Adaptive Structures and Intelligent Systems 84027, V001T04A021 2020
    Citations: 2

  • Finite Strain Constitutive Modelling of Shape Memory Alloys Considering Partial Phase Transformation with Transformation-Induced Plasticity
    G Scalet, A Karakalas, L Xu, D Lagoudas
    Shape Memory and Superelasticity 7 (2), 206-221 2021
    Citations: 1

  • Comparison of linear and torsional SMA actuators for morphing applications
    W Suk, AA Karakalas, DC Lagoudas
    Active and Passive Smart Structures and Integrated Systems XV 11588, 155-169 2021
    Citations: 1