Structural Analysis & Active Materials Group
Dept. of Mechanical Engineering & Aeronautics
IIMEC Related Activities of U. Patras on
Multi-Functional Materials
Nikolaos A. Chrysochoidis
Research Fellow
Dimitris A. Saravanos
Professor
Third Annual Meeting, Annenberg Presidential Conference Center, Texas
A&M University, College Station, Texas 18-19 January 2012
Location
Delphi
Patras
Olympia
Mycenae
Outline
Organization of International Conference ICAST 2011
supported by IIMEC
Participation in Schools organized during the last year
Participation in Workshop organized at the field of wind
energy - Egypt
Student exchanges
Other Research activities of University of Patras in the
areas of IIMEC
Future Activities
Outline
Organization of International Conference ICAST 2011
supported by IIMEC
Participation in Schools organized during the last year
Participation in Workshop organized at the field of wind
energy - Egypt
Student exchanges
Other Research activities of University of Patras in the
areas of IIMEC
Future Activities
ICAST2011
22nd International Conference on Adaptive Structures Technologies
October 10-12, 2011
Corfu, Greece
Conference Chair Dimitris Saravanos
Professor, University of Patras
London
Berlin
(Potsdam)
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Paris
Ascona
Rome
Corfu
Athens
Three Days
Two parallel sessions
108 Participants
3 keynote lectures
65 Oral presentations
38 Posters
ICAST 2011 - Sessions
Sessions:
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Multi functional materials
Morphing Structures
Semi- Active vibration control
Energy Harvesting and self-powered devices
Adaptive Wind Turbine Rotors
Active Contol
Damping
SHM
Actuation and Sensing Devices
ICAST 2011 - IIMEC Support
Support of 15 students covering their registration and lodging expenses
NAME
ORGANIZATION
City/Country
IIMEC:
Brian Lester
Jeffrey Kauffman
Michael Pontecorvo
El bekkaye MERRIMI
Dimitrios Chortis
Alexandros Solomou
Texas A&M University
The Pennsylvania State University
Pennsylvania State University
Université Mohammed V-Souissi
University of Patras
University of Patras
College Station - USA
Pennsylvania - USA
Pennsylvania USA
Rabat-Morocco
Patras, Greece
Patras, Greece
USA:
Julianna Abel
Ya(Sophia) Wang
WonHee Kim
University of Michigan
Virginia Tech
University of Michigan
Ann Arbor - USA
Blacksburg, VA - USA
Ann Arbor, USA
International:
Peerawan Wiwattananon
Paolo Basso
Wander Vieira
Hongli Ji
Yuji Takada
Shih-Chieh Lin
Delft University of Technology, Aerospace
Engineering
University of Pavia
Rotorcraft Research Group- Carleton University
Nanjing University of Aeroautics & Astranautics
Aichi institute of technology
Istitute of Applied Mechanics, National Taiwan
University
Delft - Netherlands
Pavia - Italy
Ottawa - CANADA
Nanjing - China
Toyota - Japan
Taipei - Taiwan
ICAST 2011
•
•
•
•
•
•
Three Days
Two parallel sessions
108 Participants
3 keynote lectures
65 Oral presentations
38 Posters
Outline
Organization of International Conference ICAST
2011 with the IIMEC Support
Participation in Schools organized during the last year
Participation in Workshop organized at the field of wind
energy
Student exchange
Other Research activities of University of Patras in the
areas of IIMEC
Future Activities
Summer School
Lectures covered topics on :
• Thermodynamics
• Micromechanics
• Homogenisation
• Modeling & Characterization of SMA
• Fatigue and Damage mechanics
•Non Destructive Evaluation
• Applications of SMA
Social Events:
• Visit to Dodoni Theatre
• Excursion to Zagorochoria (Monodendri)
• Dinner at Mystagogia
University of Patras participated with two students: Konstantinos Georgopoulos-Bosinas
and Thodoris Machairas having interactions with students from various nationalities.
Winter School
IIMEC WINTER SCHOOL
computational materials
science across scales
January 8th-17th, 2012 in
College Station, TX
Nikolaos Chrysochoidis
attended to the Winter
School thanks to the full
IIMEC support
Outline
Organization of International Conference ICAST
2011 with the IIMEC Support
Participation on Schools organized during the last year
Participation on a Workshop organized at the field of
wind energy
Students exchange
Other Research activities of University of Patras in the
areas of IIMEC
Future Activities
Material Coupling Effects on Composite
Structures
Chortis, D. I, and Saravanos, D. A., 2011,
“Linear and non-linear coupled damped structural dynamics models
for large wind turbine blades”,
International Workshop: Advanced Materials for Wind Turbine Blades, Cairo, Egypt.
Objectives:
Strong effect of coupling terms on blade mode shape.
The difference is eliminated at θ=00 and 900 where the
material coupling effect is physically vanished.
Included into DAMPBEAM FE and
Structural Dynamics code.
1.2
0.25
Coupling
NO Coupling
0.20
0.15
0.10
0.05
1.1
1.0
st
Material Coupling Effect on Gl/Ep BladeModels with Various Ply Angle
Laminations at Girder
Evaluated nonlinear effects on stiffness and damping
of large blades
1 Modal Loss Factor (%)
–
Model effects of coupling on blade
structural stiffness and damping
1st Mode Shape
Twisting (θx) / Bending (by) Angle
–
Notable Results:
0.00
0.9
0.8
0.7
0.6
0.5
Coupling
NO Coupling
0.4
0.3
0.2
0.1
0.0
-0.05
0
10
20
30
40
50
60
Ply Angle (degress)
70
80
90
0
10
20
30
40
50
60
Ply Angle (degree)
70
80
90
Nonlinear Damped Structural Dynamics
Objectives:
Predicted Stiffening Effect due to rotational loads and
gravity
Model nonlinear effects due to
large displacementsrotations on blade stiffness
and damping
Box-Section Girder Model of 54m WT blade
Fxcentrifugal
New nonlinear damped beam
Finite Element
Nonlinear DAMPBEAM code.
st
nd
1 bending
2.5
Fxgravity
st
2 bending
Modal Loss Factor (%)
Natural Frequency (Hz)
2 bending
0.80
2.0
1.5
1.0
0.5
0.0
nd
1 bending
0
2
4
6
8
10
Angular Velocity (rpm)
12
14
16
0.75
0.70
0.65
0.60
0.1
0.0
0
2
4
6
8
10
Angular Velocity (rpm)
12
14
16
Outline
Organization of International Conference ICAST
2011 with the IIMEC Support
Participation on Schools organized during the last year
Participation on a Workshop organized at the field of
wind energy
Student exchange
Other Research activities of University of Patras in the
areas of IIMEC
Future Activities
Student Exchange
TAMU visit:
Duration: 3 months , 5 May to 5 August
Visitor: Alexandros Solomou
Phd candidate at University of Patras, Greece
• Subjects :
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1D Users material Subroutine with thermomechanical coupling
A new 1D users material subroutine developed for the simulation of the SMA wires response taking into account the
thermomechanical coupling in constitutive laws. The developed UMAT captures efficiently Sma’s thermomechanical
response making the designing process of Sma wire actuator more effective. In this work Lagouda’s and coworkers Sma’s
constitutive model is used.
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Back stress model
The Back stress model aims to capture the highly anisotropic transformation strain generation and recovery observed in
actuator components subjected to common material processing and training methods.
1D UMAT with thermomechanical coupling
COMPARISON OF COUPLED AND UNCOUPLED
MODEL
Back Stress Model
Motivation
Training load affects the transformation strain that
: a material exhibits during actuation procedures. This effect is due
to the internal stresses that are accumulated during training and their direction is strongly related to the type of
training load. By implementing the back stress in the model we are trying to capture internal stress effects.
Experimental procedure
Step 1 : Training of the
specimen under axial load
Step 4 : Cooling of the
specimen while the applied
moment and axial force are
remained constant in order to
calculate the transformation
strain
Step 2 : Applying Moment
Step 3 : Adding axial force
Step 5 : Heating of the
specimen while the applied
moment and axial force are
remained constant
Back Stress Model (Continue..)
 t  

Transformation strain evolution equation
3 cur
(σ + β)
H (   )
2
(   )
β : Back stress tensor
Transformation strain direction
Equivalent shear transformation strain
Transformation strain Magnitude
Tensile transformation strain
Outcome: An upcoming joint paper at the SPIE conference at March 2012
coauthored by Darren Hartl and Dimitris Lagoudas
Outline
Organization of International Conference ICAST
2011 with the IIMEC Support
Participation on Schools organized during the last year
Participation on a Workshop organized at the field of
wind energy
Students exchange
Other Research activities of University of Patras in the
areas of IIMEC
Future Activities
Structural Health Monitoring of Polymer Matrix Composites
Non linear Ultrasonics Technique
Objective: Development of a new Structural Health Monitoring methodology based on damage detection
via non –linear wave modulation characteristics.
Structural Health Monitoring of Polymer Matrix Composites
Non linear Ultrasonics Technique
Experimental Setup for Impact Damage Detection in Composite Plates
Results: Detection of Impact Damage
4J Impact load
Healthy
Conclusions:
 Ability to reveal even small
damage sizes
 Efficient for all common damage
types of composites:
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Delamination Debondings
Matrix cracks
Single lap adhesive joints
Development of Morphing Chevron with SMA wires
Morphing Chevron
Objectives
>7o
Framework
• Implementation of constitutive model in
Abaqus UMAT
• Primary FEA for proof of concept
• SMA characterization
• Detailed FE Analyses
• Manufacturing & Testing of Adaptive strip &
full scale prototype
Adaptive Strip
• Development of an adaptive chevron in
order to reduce the noise levels during
airplane’s operation.
• Chevron to move between two positions:
•deformed during take off/landing (min
7degs penetration)
•Open in cruising.
• Apply internal SMA wire actuators
• Target shape: minimum of 7 degs tip
deflection
Adaptive Full Scale Prototype
Outline
Organization of International Conference ICAST
2011 with the IIMEC Support
Participation on Schools organized during the last year
Participation on a Workshop organized at the field of
wind energy
Students exchange
Other Research activities of University of Patras in the
areas of IIMEC
Future Activities
Future Activities
Organization of a School Related on Modeling of Wind Turbine Blades
University of
Patras
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National Technical
University of
Athens
Participation of DTU Risø and Delft University
Possible participation of British University in Cairo
Topics
Modeling tools for Wind
Turbine Blades
Aeroelasticity
Damping
Non linear Effects
Design Optimization
Center of Recycled
Energy Sources
Future Activities
Students Exchanges
• Expected visit of one student from TAMU to University of
Patras to spend three months in Greece
• Visit of Thodoris Machairas at Tamu of three months from
May to July 2012
Thanks for the Attention
Special thanks to the IIMEC institute
Questions?